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    Beta-Blockers with Alpha Blockade

    DEA CLASS

    Rx

    DESCRIPTION

    Oral and parenteral combined selective alpha1-blocker and nonselective beta-blocker
    Used for hypertension
    Orthostatic hypotension common after intravenous use

    COMMON BRAND NAMES

    Normodyne, Trandate

    HOW SUPPLIED

    Labetalol/Labetalol Hydrochloride/Normodyne/Trandate Intravenous Inj Sol: 1mL, 5mg
    Labetalol/Labetalol Hydrochloride/Normodyne/Trandate Intravenous Sol: 1mL, 5mg
    Labetalol/Labetalol Hydrochloride/Normodyne/Trandate Oral Tab: 100mg, 200mg, 300mg

    DOSAGE & INDICATIONS

    For the treatment of hypertension.
    Oral dosage (outpatient titration and maintenance dosing)
    Adults

    100 mg PO twice daily, initially. Titrate dosage by 100 to 200 mg twice daily every 2 to 3 days until goal blood pressure is attained. Usual dose: 200 to 400 mg twice daily. Max: 2,400 mg/day.[28106]

    Oral dosage (inpatient titration and maintenance dosing)
    Adults

    200 mg PO once, then 200 to 400 mg PO in 6 to 12 hours, then 200 mg PO twice daily. Titrate dosage by 200 to 400 mg twice daily every day until goal blood pressure is attained. May give total daily dose in 3 divided doses. Max: 2,400 mg/day.

    Intravenous dosage
    Adults

    10 to 20 mg IV, then 20 to 80 mg IV every 10 to 30 minutes until goal blood pressure is attained. Max cumulative dose: 300 mg.[42601] [64716]

    Children† and Adolescents†

    0.2 to 1 mg/kg/dose (Max: 40 mg/dose) IV every 10 minutes until goal blood pressure is attained.

    Continuous Intravenous Infusion dosage
    Adults

    1 to 8 mg/minute continuous IV infusion until goal blood pressure is attained then transition to oral labetalol. Usual total dose: 50 to 200 mg. Max cumulative dose: 300 mg.[42601] [64716]

    Children† and Adolescents†

    0.25 to 3 mg/kg/hour continuous IV infusion. In a retrospective report, 41 children (1 month to 17 years, mean, 7.97 years) received incremental infusions of 1 to 3 mg/kg/hour.

    For the treatment of dysautonomia† due to tetanus†.
    Continuous Intravenous Infusion dosage
    Adults

    0.25 to 1 mg/minute continuous IV infusion.

    For the treatment of hypertensive crisis† (e.g., hypertensive urgency† or hypertensive emergency†).
    Intravenous dosage
    Adults

    10 to 20 mg IV, then 20 to 80 mg IV every 10 to 30 minutes until goal blood pressure is attained. Max cumulative dose: 300 mg.

    Continuous Intravenous Infusion dosage
    Adults

    10 to 20 mg IV, then 0.5 to 2 mg/minute continuous IV infusion initially. Titrate every 15 minutes until goal blood pressure is attained. May repeat or double bolus dose after 10 minutes before starting infusion. Max: 10 mg/minute. Max cumulative dose: 300 mg.

    Children and Adolescents

    0.2 to 1 mg/kg IV bolus (Max: 40 mg), then 0.25 to 3 mg/kg/hour continuous IV infusion.

    †Indicates off-label use

    MAXIMUM DOSAGE

    Adults

    2,400 mg/day PO; 300 mg/day IV.

    Geriatric

    2,400 mg/day PO; 300 mg/day IV.

    Adolescents

    1 mg/kg/dose (Max: 40 mg/dose) IV and 3 mg/kg/hour continuous IV infusion have been used off-label for the treatment of hypertension.

    Children

    1 mg/kg/dose (Max: 40 mg/dose) IV and 3 mg/kg/hour continuous IV infusion have been used off-label for the treatment of hypertension.

    Infants

    Safety and efficacy have not been established.

    Neonates

    Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed. Use labetalol with caution in patients with hepatic impairment as labetalol metabolism may be impaired.

    Renal Impairment

    Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.
     
    Hemodialysis
    Hemodialysis does not remove a significant amount of labetalol from the systemic circulation.
     
    Peritoneal Dialysis
    Peritoneal dialysis does not remove a significant amount of labetalol from the systemic circulation.

    ADMINISTRATION

    Oral Administration

    Assurance of a lack of exaggerated hypotensive response can be established in the office setting since the full antihypertensive effect of labetalol is usually seen within 1 to 3 hours of the initial dose or dose increment. The need for further titration can be assessed at subsequent visits, approximately 12 hours after a dose.[28106]

    Injectable Administration

    Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit. Do not use unless the solution is clear (colorless to light yellow).

    Intravenous Administration

    Keep patients in a supine position during administration. Establish the patient's ability to tolerate an upright position before permitting any ambulation.
    Monitor blood pressure during and after completion of the injections or infusions.[42601]
     
    Direct IV Injection
    No dilution necessary.
    Monitor supine blood pressure immediately before and 5 and 10 minutes after injection.
    Inject slowly over 2 minutes.[42601]
     
    Preparation of IV Infusion from Vials
    Dilute 200 mg labetalol in 160 mL of a compatible IV solution for a final concentration of 1 mg/mL. Alternatively, dilute 200 mg in 250 mL of a compatible IV solution for a final concentration of approximately 2 mg/3 mL.
    Compatible IV solutions include Lactated Ringer's Injection, 5% Dextrose and Lactated Ringer's Injection, 5% Dextrose Injection, 0.9% Sodium Chloride Injection, 5% Dextrose and 0.2% Sodium Chloride Injection, 2.5% Dextrose and 0.45% Sodium Chloride Injection, 5% Dextrose and 0.9% Sodium Chloride Injection, and 5% Dextrose and 0.33% Sodium Chloride Injection.[42601]
    ASHP Recommended Standard Concentrations for Adult Continuous Infusions: 5 mg/mL.[64020]
    Storage: The diluted solution is stable for 24 hours refrigerated or at room temperature.[42601]
     
    Continuous IV Infusion
    Infuse at a rate of 2 mg/minute, initially; adjust infusion rate according to blood pressure response.
    Stop the infusion once a satisfactory response is obtained and start oral labetalol when the supine blood pressure has started to rise.[42601]
    Storage: The diluted solution is stable for 24 hours refrigerated or at room temperature.[42601] Once the infusion has started, discard any solution remaining from the premixed bag at 24 hours.

    STORAGE

    Normodyne:
    - Discard product if it contains particulate matter, is cloudy, or discolored
    - Do not freeze
    - Protect from light
    - Store at controlled room temperature (between 68 and 77 degrees F)
    - Store in carton until time of use
    Trandate:
    - Discard product if it contains particulate matter, is cloudy, or discolored
    - Do not freeze
    - Protect from light
    - Store at controlled room temperature (between 68 and 77 degrees F)
    - Store in carton until time of use

    CONTRAINDICATIONS / PRECAUTIONS

    Abrupt discontinuation, coronary artery disease

    Abrupt discontinuation of labetalol in patients with coronary artery disease may result in exacerbation of angina, myocardial infarction, or ventricular dysrhythmias. When discontinuing chronically administered oral labetalol, gradually reduce the dose over 1 to 2 weeks. Carefully observe the patient and advise them to limit physical activity. If angina significantly worsens or acute coronary insufficiency develops, reintroduce labetalol, at least temporarily, and institute other measures appropriate for the management of unstable angina. In patients without coronary artery disease, abrupt discontinuation may result in transient symptoms (e.g., tremors, sweating, palpitations, headache, malaise).

    AV block, bradycardia, cardiogenic shock, heart failure, hypotension

    Labetalol is contraindicated in patients with overt heart failure, greater than first-degree AV block, cardiogenic shock, severe bradycardia, or other conditions associated with severe and prolonged hypotension.[28106] [42601] The negative inotropic effects produced by beta-blockers can exacerbate heart failure; although use should be avoided in decompensated heart failure, labetalol can be used with caution in stable patients. Continued myocardial depression can lead to heart failure in patients with latent cardiac insufficiency. If signs and symptoms of impending heart failure develop, fully digitalize and/or give the patient a diuretic and observe closely. Withdraw labetalol therapy, gradually, if possible, if heart failure continues.[28106] [42601] Monitor heart rate and rhythm in patients receiving intravenous labetalol. Before allowing ambulation, establish the patient's ability to tolerate an upright position and observe the patient at the time of first ambulation after receiving intravenous labetalol to limit the risk of orthostatic hypotension.

    Pheochromocytoma

    Use labetalol with caution in patients with pheochromocytoma; paradoxical hypertensive responses have been reported. Although labetalol has been used to effectively lower blood pressure and relieve symptoms in patients with pheochromocytoma, it is not recommended as an agent of choice for hypertensive emergencies related to pheochromocytoma.

    Hypertensive crisis

    Use caution when reducing severely elevated blood pressure (e.g., hypertensive crisis). A number of adverse reactions, including cerebral infarction, optic nerve infarction, angina, and ischemic changes in the electrocardiogram, have been reported with other agents when severely elevated blood pressure was reduced over time courses of several hours to as long as 1 or 2 days. Reduce blood pressure over as long a period of time as is compatible with the patient's clinical status. For adult patients with a compelling condition (e.g., aortic dissection, severe preeclampsia or eclampsia), reduce systolic blood pressure to less than 140 mmHg (less than 120 mmHg in aortic dissection) during the first hour. For adults without a compelling condition, reduce systolic blood pressure by no more than 25% within the first hour, then to 160/100 mmHg within the next 2 to 6 hours, then cautiously to normal during the next 24 to 48 hours.

    Asthma, bronchitis, chronic obstructive pulmonary disease (COPD), emphysema

    Labetalol is contraindicated in patients with asthma or obstructive airway disease (e.g., chronic obstructive pulmonary disease (COPD), chronic bronchitis, emphysema). If use is absolutely necessary, use the lowest effective dose so that inhibition of endogenous or exogenous beta-agonists is minimized. If bronchospasm occurs, discontinue labetalol immediately and treat as appropriate.

    Diabetes mellitus

    Monitor blood glucose concentrations in patients receiving labetalol. Beta-blockers may inhibit catecholamine-induced glycogenolysis, gluconeogenesis, and lipolysis, predisposing to hypoglycemia.[53721] Additionally, beta-blockers can mask signs of hypoglycemia (e.g., tachycardia), which may be particularly detrimental in patients with labile diabetes mellitus. Beta-blockade also reduces the release of insulin in response to hyperglycemia, which may make it necessary to adjust the dose of antidiabetic drugs.[28106] [42601] In addition to acute blood glucose effects, beta-blockers have been shown to increase the risk of developing diabetes mellitus in adult hypertensive patients; this risk should be evaluated relative to the proven benefits of beta-blockers in reducing cardiovascular events.[26823]

    Coronary artery bypass graft surgery (CABG), surgery

    Do not routinely withdraw beta-blocker therapy before surgery. Evaluate the risks vs. benefits in individual patients by considering the type of surgery (e.g., cardiac vs. noncardiac), coexisting health conditions, and anesthetic strategy. Guidelines recommend continuance in patients already on beta-blocker therapy; however, initiation well before a planned procedure and careful perioperative titration to achieve adequate heart rate control while avoiding significant bradycardia or hypotension are suggested. In an uncontrolled study of patients after coronary artery bypass graft surgery (CABG), patients with low cardiac indices and elevated systemic vascular resistance after intravenous labetalol experienced significant declines in cardiac output with little change in systemic vascular resistance. One of these patients developed hypotension after labetalol treatment. Therefore, avoid labetalol use in such patients.

    Hepatic disease

    Use labetalol with caution in patients with hepatic disease due to decreased drug metabolism. Severe hepatocellular injury has rarely occurred after both short- and long-term treatment and may be slowly progressive even with minimal symptomatology. Monitor liver function tests periodically and at the first sign or symptom of hepatic dysfunction in patients taking labetalol. If jaundice occurs or there is evidence of liver injury, discontinue labetalol and do not restart.

    Beta-blocker hypersensitivity

    Labetalol is contraindicated in patients with a history of hypersensitivity to any component of the product. Cross sensitivity between beta-blockers (beta-blocker hypersensitivity) can occur. While taking beta-blockers, patients with a history of severe anaphylactic reaction to a variety of allergens may be more reactive to repeated challenge (accidental, diagnostic, or therapeutic). These patients may also be unresponsive to the usual doses of epinephrine used to treat the allergic reaction.

    Laboratory test interference

    Labetalol may cause laboratory test interference. The presence of labetalol metabolites in the urine may result in falsely elevated concentrations of urinary catecholamines, metanephrine, normetanephrine, and vanillylmandelic acid (VMA) when measured by fluorimetric or photometric methods. Use a specific method, such as a high-performance liquid chromatographic assay with solid-phase extraction, for determining catecholamine concentrations in patients suspected of having pheochromocytoma. Labetalol has also been reported to produce a false-positive for amphetamine when screening urine using the commercially available assay methods Toxi-Lab A (thin-layer chromatographic assay) and Emit-d.a.u. (radioenzymatic assay). Confirm results using a more specific method (e.g., gas chromatographic-mass spectrometer technique) if a test is positive in patients taking labetalol.[28106] [42601]

    Ocular surgery

    Patients treated with alpha1-blockers, including labetalol, may be at risk for intraoperative floppy iris syndrome (IFIS) during cataract ocular surgery. There does not appear to be a benefit of stopping alpha1-blocker therapy before surgery; however, the possible modifications to surgical technique (e.g., utilization of iris hooks, iris dilator rings, or viscoelastic substances) may be necessary. IFIS is characterized by the combination of a flaccid iris that billows in response to intraoperative irrigation currents, progressive intraoperative miosis despite preoperative dilation with standard mydriatic drugs, and potential prolapse of the iris toward the phacoemulsification incisions.

    Geriatric

    Caution geriatric patients about the possibility of orthostatic symptoms; some patients 60 years and older have experienced orthostatic hypotension, dizziness, or lightheadedness during treatment with labetalol. When using the injection, establish the patient's ability to tolerate an upright position before permitting ambulation. Some pharmacokinetic studies indicate labetalol elimination is reduced in elderly patients. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities. According to the OBRA guidelines, antihypertensive regimens should be individualized to achieve the desired outcome while minimizing adverse effects. Antihypertensives may cause dizziness, postural hypotension, fatigue, and there is an increased risk for falls. Additionally, beta-blockers are associated with depression, bronchospasm, cardiac decompensation that may require dose adjustments in those with acute heart failure, and they may mask some symptoms of hypoglycemia (e.g., tachycardia). Beta-blockers metabolized in the liver may have an increased effect or accumulate in those with hepatic impairment. There are many drug interactions that can potentiate the effects of antihypertensives. Beta-blockers may cause or exacerbate bradycardia, particularly in patients receiving other medications that affect cardiac conduction. When discontinuing, a gradual taper may be required to avoid adverse consequences caused by abrupt discontinuation.

    Pregnancy

    Labetalol crosses the placenta. Extensive experience with the use of labetalol during human pregnancy, based on published interventional and observational studies, has not identified a drug-associated risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes. However, most studies reported the use of intravenous labetalol after 20 weeks gestation. These studies cannot definitely establish an absence of risk during pregnancy, as there have been inconsistent findings of intrauterine growth retardation, preterm birth, and perinatal mortality with maternal use of labetalol during pregnancy. In animal reproduction studies, oral administration of labetalol during organogenesis at doses up to 4- to 6-times the maximum recommended human dose (MRHD) resulted in no fetal malformation; however, fetal resorption was seen in both species (rats and rabbits) at doses approximating the MRHD. Monitor neonates born to mothers who are receiving labetalol during pregnancy for symptoms of hypotension, bradycardia, hypoglycemia, and respiratory depression and manage accordingly. Hypertension in pregnancy increases the maternal risk for preeclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section, post-partum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death. Monitor pregnant women with hypertension carefully monitored and manage accordingly.

    Breast-feeding

    Consider the developmental and health benefits of breast-feeding along with the mother's clinical need for labetalol and any potential adverse effects on the breast-fed infant from labetalol or the underlying maternal condition. Small amounts of labetalol (approximately 0.004% of the maternal dose) are excreted in human milk. There are no data on the effects on the breast-fed infant or on milk production. Previous American Academy of Pediatrics (AAP) recommendations considered labetalol to be generally compatible with breast-feeding. Other experts consider labetalol to be compatible with breast-feeding in most infants; however, alternative agents may be preferred for the mothers of premature infants. Propranolol, another beta-blocker considered to be compatible with breast-feeding by previous AAP recommendations, may be a potential alternative for some patients.

    Infertility, reproductive risk

    Beta-blockers, including labetalol, may be associated with reproductive risk and cause male infertility via erectile dysfunction and inhibition of sperm motility.

    ADVERSE REACTIONS

    Severe

    hepatotoxicity / Delayed / 0-1.0
    visual impairment / Early / 1.0-1.0
    myocardial infarction / Delayed / Incidence not known
    AV block / Early / Incidence not known
    cardiac arrest / Early / Incidence not known
    bradycardia / Rapid / Incidence not known
    heart failure / Delayed / Incidence not known
    hepatic necrosis / Delayed / Incidence not known
    laryngospasm / Rapid / Incidence not known
    bronchospasm / Rapid / Incidence not known
    angioedema / Rapid / Incidence not known
    anaphylactoid reactions / Rapid / Incidence not known
    thrombotic thrombocytopenic purpura (TTP) / Delayed / Incidence not known
    agranulocytosis / Delayed / Incidence not known
    lupus-like symptoms / Delayed / Incidence not known

    Moderate

    orthostatic hypotension / Delayed / 1.0-58.0
    ejaculation dysfunction / Delayed / 0-5.0
    elevated hepatic enzymes / Delayed / 4.0-4.0
    impotence (erectile dysfunction) / Delayed / 1.0-4.0
    edema / Delayed / 0-2.0
    dyspnea / Early / 2.0-2.0
    hypotension / Rapid / 1.0-1.0
    wheezing / Rapid / 1.0-1.0
    depression / Delayed / Incidence not known
    memory impairment / Delayed / Incidence not known
    confusion / Early / Incidence not known
    hypertension / Early / Incidence not known
    angina / Early / Incidence not known
    jaundice / Delayed / Incidence not known
    hepatitis / Delayed / Incidence not known
    hypoglycemia / Early / Incidence not known
    hyperglycemia / Delayed / Incidence not known
    diabetes mellitus / Delayed / Incidence not known
    erythema / Early / Incidence not known
    psoriaform rash / Delayed / Incidence not known
    floppy iris syndrome / Delayed / Incidence not known
    withdrawal / Early / Incidence not known
    colitis / Delayed / Incidence not known
    myopathy / Delayed / Incidence not known
    urinary retention / Early / Incidence not known

    Mild

    nausea / Early / 0-19.0
    dizziness / Early / 1.0-16.0
    fatigue / Early / 1.0-10.0
    paresthesias / Delayed / 0-7.0
    nasal congestion / Early / 1.0-6.0
    hyperhidrosis / Delayed / 0-4.0
    dyspepsia / Early / 0-4.0
    vomiting / Early / 0-4.0
    yawning / Early / 0-3.0
    drowsiness / Early / 0-3.0
    headache / Early / 2.0-2.0
    vertigo / Early / 1.0-2.0
    asthenia / Delayed / 1.0-1.0
    hypoesthesia / Delayed / 1.0-1.0
    flushing / Rapid / 1.0-1.0
    pruritus / Rapid / 1.0-1.0
    rash / Early / 1.0-1.0
    diarrhea / Early / 0-1.0
    dysgeusia / Early / 1.0-1.0
    emotional lability / Early / Incidence not known
    syncope / Early / Incidence not known
    alopecia / Delayed / Incidence not known
    lichen planus-like eruption / Delayed / Incidence not known
    urticaria / Rapid / Incidence not known
    maculopapular rash / Early / Incidence not known
    muscle cramps / Delayed / Incidence not known
    xerophthalmia / Early / Incidence not known
    fever / Early / Incidence not known

    DRUG INTERACTIONS

    Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Acetaminophen; Caffeine; Phenyltoloxamine; Salicylamide: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Adenosine: (Moderate) Use adenosine with caution in the presence of beta blockers due to the potential for additive or synergistic depressant effects on the sinoatrial and atrioventricular nodes.
    Albiglutide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Aldesleukin, IL-2: (Moderate) Beta blockers may potentiate the hypotension seen with aldesleukin, IL 2.
    Alemtuzumab: (Moderate) Alemtuzumab may cause hypotension. Careful monitoring of blood pressure and hypotensive symptoms is recommended especially in patients with ischemic heart disease and in patients on antihypertensive agents.
    Alfentanil: (Moderate) Alfentanil may cause bradycardia. The risk of significant hypotension and/or bradycardia during therapy with alfentanil is increased in patients receiving beta-blockers.
    Alfuzosin: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensive agents has the potential to cause hypotension in some patients. Alfuzosin (2.5 mg, immediate-release) potentiated the hypotensive effects of atenolol (100 mg) in eight healthy young male volunteers. The Cmax and AUC of alfuzosin was increased by 28% and 21%, respectively. Alfuzosin increased the Cmax and AUC of atenolol by 26% and 14%, respectively. Significant reductions in mean blood pressure and in mean heart rate were reported with the combination.
    Aliskiren; Amlodipine: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Alogliptin; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Alpha-blockers: (Moderate) Orthostatic hypotension may be more likely if beta-blockers are coadministered with alpha-blockers.
    Alpha-glucosidase Inhibitors: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Alprostadil: (Minor) The concomitant use of systemic alprostadil injection and antihypertensive agents, such as beta-clockers, may cause additive hypotension. Caution is advised with this combination. Systemic drug interactions with the urethral suppository (MUSE) or alprostadil intracavernous injection are unlikely in most patients because low or undetectable amounts of the drug are found in the peripheral venous circulation following administration. In those men with significant corpora cavernosa venous leakage, hypotension might be more likely. Use caution with in-clinic dosing for erectile dysfunction (ED) and monitor for the effects on blood pressure. In addition, the presence of medications in the circulation that attenuate erectile function may influence the response to alprostadil. However, in clinical trials with alprostadil intracavernous injection, anti-hypertensive agents had no apparent effect on the safety and efficacy of alprostadil.
    Amifostine: (Major) Patients receiving beta-blockers should be closely monitored during amifostine infusions due to additive effects. Patients receiving amifostine at doses recommended for chemotherapy should have antihypertensive therapy interrupted 24 hours preceding administration of amifostine. If the antihypertensive cannot be stopped, patients should not receive amifostine.
    Amiodarone: (Moderate) Amiodarone prolongs AV nodal refractory period and decreases sinus node automaticity. Because beta-blockers have similar effects, concomitant administration of beta-blockers with amiodarone may cause additive electrophysiologic effects (slow sinus rate or worsen AV block), resulting in symptomatic bradycardia, sinus arrest, and atrioventricular block. This is particularly likely in patients with preexisting partial AV block or sinus node dysfunction. While combination amiodarone and beta-blockers should be used cautiously and with close monitoring, it should be noted that post-hoc analysis of amiodarone therapy in patients after acute myocardial infarction in two clinical trials revealed that amiodarone in addition to a beta-blocker significantly lowered the incidence of cardiac and arrhythmic death or resuscitated cardiac arrest when compared with amiodarone or beta-blocker therapy alone.
    Amlodipine: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amlodipine; Atorvastatin: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amlodipine; Benazepril: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amlodipine; Celecoxib: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amlodipine; Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amlodipine; Olmesartan: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amlodipine; Telmisartan: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amlodipine; Valsartan: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Amobarbital: (Moderate) Although concurrent use of amobarbital with antihypertensive agents may lead to hypotension, barbiturates, as a class, can enhance the hepatic metabolism of beta-blockers that are significantly metabolized by the liver. Beta-blockers that may be affected include betaxolol, labetalol, metoprolol, pindolol, propranolol, and timolol. Clinicians should closely monitor patients blood pressure during times of coadministration.
    Amoxapine: (Moderate) An increased incidence of labetalol-induced tremor has been reported in patients being treated concurrently with tricyclic antidepressants. Similar interactions would be expected with the related cyclic antidepressant amoxapine.
    Amyl Nitrite: (Moderate) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as antihypertensive agents or other peripheral vasodilators. Patients should be monitored more closely for hypotension if nitroglycerin, including nitroglycerin rectal ointment, is used concurrently with any beta-blockers.
    Antithyroid agents: (Minor) Hyperthyroidism may cause increased clearance of beta blockers that possess a high extraction ratio. A dose reduction of some beta-blockers may be needed when a hyperthyroid patient treated with methimazole becomes euthyroid.
    Apomorphine: (Moderate) Use of beta blockers and apomorphine together can increase the hypotensive effects of apomorphine. Monitor blood pressure regularly during use of this combination.
    Apraclonidine: (Minor) Theoretically, additive blood pressure reductions could occur when apraclonidine is combined with antihypertensive agents.
    Aripiprazole: (Minor) Aripiprazole may enhance the hypotensive effects of antihypertensive agents. It may be advisable to monitor blood pressure when these medications are coadministered.
    Articaine; Epinephrine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Thus, patients receiving antihypertensive agents may experience additive hypotensive effects.
    Asenapine: (Moderate) Secondary to alpha-blockade, asenapine can produce vasodilation that may result in additive effects during concurrent use of labetalol. The potential reduction in blood pressure can precipitate orthostatic hypotension and associated dizziness, tachycardia, and syncope. If concurrent use is necessary, patients should be counseled on measures to prevent orthostatic hypotension, such as sitting on the edge of the bed for several minutes prior to standing in the morning and rising slowly from a seated position. Close monitoring of blood pressure is recommended until the full effects of the combination therapy are known; the labetalol dosage may need to be adjusted.
    Aspirin, ASA: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Butalbital; Caffeine: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Butalbital; Caffeine; Codeine: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Caffeine: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Caffeine; Dihydrocodeine: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Caffeine; Orphenadrine: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Carisoprodol: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Carisoprodol; Codeine: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Dipyridamole: (Major) Beta-blockers should generally be withheld before dipyridamole-stress testing. Monitor the heart rate carefully following the dipyridamole injection. (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Omeprazole: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Oxycodone: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Aspirin, ASA; Pravastatin: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Atazanavir: (Moderate) Atazanavir can prolong the PR interval. Coadministration with other agents that prolong the PR interval, like beta blockers, may result in elevated risk of conduction disturbances and atrioventricular block.
    Atazanavir; Cobicistat: (Moderate) Atazanavir can prolong the PR interval. Coadministration with other agents that prolong the PR interval, like beta blockers, may result in elevated risk of conduction disturbances and atrioventricular block.
    Azelastine; Fluticasone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Baclofen: (Moderate) Baclofen has been associated with hypotension. Concurrent use with baclofen and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
    Beclomethasone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Belladonna Alkaloids; Ergotamine; Phenobarbital: (Moderate) Concurrent use of beta-blockers and ergot alkaloids should be approached with caution. Concomitant administration with beta-blockers may enhance the vasoconstrictive action of certain ergot alkaloids including dihydroergotamine, ergotamine, methylergonovine, and methysergide. The risk of peripheral ischemia, resulting in cold extremities or gangrene, has been reported to be increased when ergotamine or dihydroergotamine is coadministered with selected beta-blockers, including propranolol, a beta-blocker commonly used for migraine prophylaxis. However, the precise mechanism of these interactions remains elusive. Additionally, because of the potential to cause coronary vasospasm, these ergot alkaloids could antagonize the therapeutic effects of anti-anginal agents including beta-blockers; clinicians should keep in mind that ergot alkaloids are contraindicated for use in patients with coronary heart disease or hypertension.
    Beta-agonists: (Moderate) Use of a beta-1-selective (cardioselective) beta blocker is recommended whenever possible when this combination of drugs must be used together. Monitor the patients lung and cardiovascular status closely. Beta-agonists and beta-blockers are pharmacologic opposites, and will counteract each other to some extent when given concomitantly, especially when non-cardioselective beta blockers are used. Beta-blockers will block the pulmonary effects of inhaled beta-agonists, and in some cases may exacerbate bronchospasm in patients with reactive airways. Beta-agonists can sometimes increase heart rate or have other cardiovascular effects, particularly when used in high doses or if hypokalemia is present.
    Betamethasone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Bismuth Subsalicylate: (Moderate) Concurrent use of beta-blockers with bismuth subsalicylate and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Concurrent use of beta-blockers with bismuth subsalicylate and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Bosentan: (Moderate) Although no specific interactions have been documented, bosentan has vasodilatory effects and may contribute additive hypotensive effects when given with beta-blockers.
    Bretylium: (Moderate) Bretylium and beta-blockers may have an additive effect when used concomitantly; monitor for hypotension or marked bradycardia, which may produce vertigo, syncope, or postural hypotension.
    Brexpiprazole: (Moderate) Due to brexpiprazole's antagonism at alpha 1-adrenergic receptors, the drug may enhance the hypotensive effects of alpha-blockers and other antihypertensive agents.
    Budesonide: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Budesonide; Formoterol: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Budesonide; Glycopyrrolate; Formoterol: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Bupivacaine Liposomal: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Use extreme caution with the concomitant use of bupivacaine and antihypertensive agents. Peripheral vasodilation may occur after use of bupivacaine. Thus, patients receiving antihypertensive agents may experience additive hypotensive effects. Blood concentrations of local anesthetics achieved after therapeutic doses are associated with minimal change in peripheral vascular resistance. Higher blood concentrations of local anesthetics may occur due to inadvertent intravascular administration or repeated doses.
    Bupivacaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Use extreme caution with the concomitant use of bupivacaine and antihypertensive agents. Peripheral vasodilation may occur after use of bupivacaine. Thus, patients receiving antihypertensive agents may experience additive hypotensive effects. Blood concentrations of local anesthetics achieved after therapeutic doses are associated with minimal change in peripheral vascular resistance. Higher blood concentrations of local anesthetics may occur due to inadvertent intravascular administration or repeated doses.
    Bupivacaine; Lidocaine: (Major) Drugs such as beta-blockers that decrease cardiac output reduce hepatic blood flow and thereby decrease lidocaine hepatic clearance. Also, opposing effects on conduction exist between lidocaine and beta-blockers while their effects to decrease automaticity may be additive. Propranolol has been shown to decrease lidocaine clearance and symptoms of lidocaine toxicity have been seen as a result of this interaction. This interaction is possible with other beta-blocking agents since most decrease hepatic blood flow. Monitoring of lidocaine concentrations is recommended during concomitant therapy with beta-blockers. (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Use extreme caution with the concomitant use of bupivacaine and antihypertensive agents. Peripheral vasodilation may occur after use of bupivacaine. Thus, patients receiving antihypertensive agents may experience additive hypotensive effects. Blood concentrations of local anesthetics achieved after therapeutic doses are associated with minimal change in peripheral vascular resistance. Higher blood concentrations of local anesthetics may occur due to inadvertent intravascular administration or repeated doses.
    Bupivacaine; Meloxicam: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Use extreme caution with the concomitant use of bupivacaine and antihypertensive agents. Peripheral vasodilation may occur after use of bupivacaine. Thus, patients receiving antihypertensive agents may experience additive hypotensive effects. Blood concentrations of local anesthetics achieved after therapeutic doses are associated with minimal change in peripheral vascular resistance. Higher blood concentrations of local anesthetics may occur due to inadvertent intravascular administration or repeated doses.
    Cabergoline: (Moderate) Cabergoline should be used cautiously with antihypertensive agents, including beta-blockers. Cabergoline has been associated with hypotension. Initial doses of cabergoline higher than 1 mg may produce orthostatic hypotension. It may be advisable to monitor blood pressure.
    Caffeine; Ergotamine: (Moderate) Concurrent use of beta-blockers and ergot alkaloids should be approached with caution. Concomitant administration with beta-blockers may enhance the vasoconstrictive action of certain ergot alkaloids including dihydroergotamine, ergotamine, methylergonovine, and methysergide. The risk of peripheral ischemia, resulting in cold extremities or gangrene, has been reported to be increased when ergotamine or dihydroergotamine is coadministered with selected beta-blockers, including propranolol, a beta-blocker commonly used for migraine prophylaxis. However, the precise mechanism of these interactions remains elusive. Additionally, because of the potential to cause coronary vasospasm, these ergot alkaloids could antagonize the therapeutic effects of anti-anginal agents including beta-blockers; clinicians should keep in mind that ergot alkaloids are contraindicated for use in patients with coronary heart disease or hypertension.
    Canagliflozin; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Carbidopa; Levodopa: (Moderate) Concomitant use of beta-blockers with levodopa can result in additive hypotensive effects.
    Carbidopa; Levodopa; Entacapone: (Moderate) Concomitant use of beta-blockers with levodopa can result in additive hypotensive effects.
    Cariprazine: (Moderate) Orthostatic vital signs should be monitored in patients who are at risk for hypotension, such as those receiving cariprazine in combination with antihypertensive agents. Atypical antipsychotics may cause orthostatic hypotension and syncope, most commonly during treatment initiation and dosage increases. Patients should be informed about measures to prevent orthostatic hypotension, such as sitting on the edge of the bed for several minutes prior to standing in the morning, or rising slowly from a seated position. Consider a cariprazine dose reduction if hypotension occurs.
    Ceritinib: (Major) Avoid coadministration of ceritinib with labetolol if possible due to the risk of additive bradycardia. An interruption of ceritinib therapy, dose reduction, or discontinuation of therapy may be necessary if bradycardia occurs. Bradycardia has been reported with ceritinib treatment; labetolol also causes bradycardia.
    Cevimeline: (Major) Cevimeline should be administered with caution to patients taking beta adrenergic antagonists, because of the possibility of conduction disturbances. Cevimeline can potentially alter cardiac conduction and/or heart rate. Patients with significant cardiovascular disease treated with beta-blockers may potentially be unable to compensate for transient changes in hemodynamics or rhythm induced by cevimeline. If use of these drugs together cannot be avoided, close monitoring of blood pressure, heart rate and cardiac function is advised.
    Chloroprocaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Chlorthalidone; Clonidine: (Major) Monitor heart rate in patients receiving concomitant clonidine and agents known to affect sinus node function or AV nodal conduction (e.g., beta-blockers). Severe bradycardia resulting in hospitalization and pacemaker insertion has been reported during combination therapy with clonidine and other sympatholytic agents. Concomitant use of clonidine with beta-blockers can also cause additive hypotension. Beta-blockers should not be substituted for clonidine when modifications are made in a patient's antihypertensive regimen because beta-blocker administration during clonidine withdrawal can augment clonidine withdrawal, which may lead to a hypertensive crisis. If a beta-blocker is to be substituted for clonidine, clonidine should be gradually tapered and the beta-blocker should be gradually increased over several days to avoid the possibility of rebound hypertension; administration of beta-blockers during withdrawal of clonidine can precipitate severe increases in blood pressure as a result of unopposed alpha stimulation.
    Choline Salicylate; Magnesium Salicylate: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Ciclesonide: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Cimetidine: (Moderate) Monitor for an increased incidence of labetalol-related adverse effects if cimetidine and labetalol are used concomitantly. Cimetidine increases the oral bioavailability of labetalol, possibly by decreasing first-pass liver metabolism or by increasing the oral absorption of labetalol.
    Clevidipine: (Moderate) Use clevidipine and labetalol with caution due to risk for additive negative effects on heart rate, AV conduction, and/or cardiac contractility.
    Clonidine: (Major) Monitor heart rate in patients receiving concomitant clonidine and agents known to affect sinus node function or AV nodal conduction (e.g., beta-blockers). Severe bradycardia resulting in hospitalization and pacemaker insertion has been reported during combination therapy with clonidine and other sympatholytic agents. Concomitant use of clonidine with beta-blockers can also cause additive hypotension. Beta-blockers should not be substituted for clonidine when modifications are made in a patient's antihypertensive regimen because beta-blocker administration during clonidine withdrawal can augment clonidine withdrawal, which may lead to a hypertensive crisis. If a beta-blocker is to be substituted for clonidine, clonidine should be gradually tapered and the beta-blocker should be gradually increased over several days to avoid the possibility of rebound hypertension; administration of beta-blockers during withdrawal of clonidine can precipitate severe increases in blood pressure as a result of unopposed alpha stimulation.
    Clozapine: (Moderate) Clozapine used concomitantly with the antihypertensive agents can increase the risk and severity of hypotension by potentiating the effect of the antihypertensive drug.
    Cocaine: (Major) Although beta-blockers are indicated to reduce cocaine-induced tachycardia, myocardial ischemia, and arrhythmias, concomitant use of cocaine and non-selective beta-adrenergic blocking agents, including ophthalmic preparations, can cause unopposed alpha-adrenergic activity, resulting in heart block, excessive bradycardia, or hypertension. In theory, the use of alpha-blocker and beta-blocker combinations or selective beta-blockers in low doses may not cause unopposed alpha stimulation in this situation. Labetalol, a beta-blocker with some alpha-blocking activity, has been used successfully to treat cocaine-induced hypertension. In addition, cocaine can reduce the therapeutic effects of beta-blockers.
    Co-Enzyme Q10, Ubiquinone: (Moderate) Co-enzyme Q10, ubiquinone (CoQ10) may lower blood pressure. CoQ10 use in combination with antihypertensive agents may lead to additional reductions in blood pressure in some individuals. Patients who choose to take CoQ10 concurrently with antihypertensive medications should receive periodic blood pressure monitoring. Patients should be advised to inform their prescriber of their use of CoQ10.
    Corticosteroids: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Cortisone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Crizotinib: (Major) Avoid coadministration of crizotinib with agents known to cause bradycardia, such as beta-blockers, to the extent possible due to the risk of additive bradycardia. If concomitant use is unavoidable, monitor heart rate and blood pressure regularly. An interruption of crizotinib therapy or dose adjustment may be necessary if bradycardia occurs.
    Dapagliflozin; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Cardiac and neurologic events have been reported when ritonavir was concurrently administered with beta-blockers.
    Dasiglucagon: (Minor) A temporary increase in both blood pressure and pulse rate may occur following the administration of glucagon. Patients taking beta-blockers might be expected to have a greater increase in both pulse and blood pressure. Glucagon exerts positive inotropic and chronotropic effects and may, therefore, cause tachycardia and hypertension in some patients. The increase in blood pressure and pulse rate may require therapy in some patients with coronary artery disease.
    Deflazacort: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Desflurane: (Moderate) Concurrent use of beta-blockers with desflurane may result in exaggerated cardiovascular effects (e.g., hypotension and negative inotropic effects). Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects. Withdrawal of a beta-blocker perioperatively may be detrimental to the patient's clinical status and is not recommended. Caution is advised if these drugs are administered together.
    Dexamethasone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Dexmedetomidine: (Major) In general, the concomitant administration of dexmedetomidine with antihypertensive agents could lead to additive hypotensive effects. Dexmedetomidine can produce bradycardia or AV block and should be used cautiously in patients who are receiving antihypertensive drugs that lower the heart rate such as beta-blockers.
    Dextromethorphan; Quinidine: (Major) Quinidine may have additive effects (e.g., reduced heart rate, hypotension) on cardiovascular parameters when used together with beta-blockers, like labetalol. In general, patients receiving combined therapy should be monitored for potential hypotension, orthostasis, bradycardia and/or AV block, and heart failure. Reduce the beta-blocker dosage if necessary.
    Diazoxide: (Moderate) Additive hypotensive effects can occur with the concomitant administration of diazoxide with other antihypertensive agent. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly. The manufacturer advises that IV diazoxide should not be administered to patients within 6 hours of receiving beta-blockers.
    Digoxin: (Moderate) Use with caution due to additive pharmacodynamic effects on cardiac conduction, especially in patients with pre-existing left ventricular dysfunction. The risk of additive inhibition of AV conduction is symptomatic bradycardia with hypotension or advanced AV block; whereas additive negative inotropic effects could precipitate overt heart failure in some patients. Despite potential for interactions, digoxin sometimes is intentionally used in combination with a beta-blocker to further reduce conduction through the AV node. Dosages may need adjustment in some patients.
    Dihydroergotamine: (Moderate) Concurrent use of beta-blockers and ergot alkaloids should be approached with caution. Concomitant administration with beta-blockers may enhance the vasoconstrictive action of certain ergot alkaloids including dihydroergotamine, ergotamine, methylergonovine, and methysergide. The risk of peripheral ischemia, resulting in cold extremities or gangrene, has been reported to be increased when ergotamine or dihydroergotamine is coadministered with selected beta-blockers, including propranolol, a beta-blocker commonly used for migraine prophylaxis. However, the precise mechanism of these interactions remains elusive. Additionally, because of the potential to cause coronary vasospasm, these ergot alkaloids could antagonize the therapeutic effects of anti-anginal agents including beta-blockers; clinicians should keep in mind that ergot alkaloids are contraindicated for use in patients with coronary heart disease or hypertension.
    Diltiazem: (Major) Intravenous labetalol is contraindicated with intravenous diltiazem use in close proximity (within a few hours). Fatal cardiac arrests have occurred in patients receiving intravenous beta-blockers and intravenous calcium channel blockers. Use oral labetalol and oral diltiazem with caution due to risk for additive negative effects on heart rate, AV conduction, and/or cardiac contractility.
    Dipeptidyl Peptidase-4 Inhibitors: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Dipyridamole: (Major) Beta-blockers should generally be withheld before dipyridamole-stress testing. Monitor the heart rate carefully following the dipyridamole injection.
    Disopyramide: (Major) Disopyramide and beta-blockers, like labetalol, have been used together for the treatment of ventricular arrhythmias; however, this combination should be used with caution due to the potential for additive AV blocking effects. In general, patients receiving combined therapy with disopyramide and beta-blockers should be monitored for potential bradycardia, AV block, and/or hypotension.
    Donepezil: (Moderate) The increase in vagal tone induced by some cholinesterase inhibitors may produce bradycardia, hypotension, or syncope. The vagotonic effect of these drugs may be increased when given with other medications known to cause bradycardia such as beta-blockers. These interactions are pharmacodynamic in nature rather than pharmacokinetic.
    Donepezil; Memantine: (Moderate) The increase in vagal tone induced by some cholinesterase inhibitors may produce bradycardia, hypotension, or syncope. The vagotonic effect of these drugs may be increased when given with other medications known to cause bradycardia such as beta-blockers. These interactions are pharmacodynamic in nature rather than pharmacokinetic.
    Doxazosin: (Moderate) Orthostatic hypotension may be more likely if beta-blockers are coadministered with alpha-blockers.
    Dronedarone: (Major) In dronedarone clinical trials, bradycardia was seen more frequently in patients also receiving beta blockers. If coadministration of dronedarone and a beta blocker is unavoidable, administer a low dose of the beta blocker initially and increase the dosage only after ECG verification of tolerability. Concomitant administration may decreased AV and sinus node conduction. Furthermore, dronedarone is an inhibitor of CYP2D6, and some beta blockers are substrates for CYP2D6 (e.g., metoprolol, propranolol, nebivolol, carvedilol). Coadministration of dronedarone with a single dose of propranolol and multiple doses of metoprolol increased propranolol and metoprolol exposure by 1.3- and 1.6-fold, respectively.
    Dulaglutide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Duloxetine: (Moderate) Orthostatic hypotension and syncope have been reported during duloxetine administration. The concurrent administration of labetalol and duloxetine may increase the risk of hypotension. It is advisable to monitor blood pressure if the combination is necessary.
    Dutasteride; Tamsulosin: (Minor) Tamsulosin did not potentiate the hypotensive effects of atenolol. However, since the symptoms of orthostasis are reported more frequently in tamsulosin-treated vs. placebo patients, there is a potential risk of enhanced hypotensive effects when co-administered with antihypertensive agents
    Empagliflozin; Linagliptin; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Empagliflozin; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Enalapril; Felodipine: (Moderate) Coadministration of felodipine and labetalol can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Encainide: (Major) Pharmacologically, beta-blockers, like labetalol, cause AV nodal conduction depression and additive effects are possible when used in combination with encainide. When used together, AV block can occur. Patients should be monitored closely and the dose should be adjusted according to clinical response.
    Enflurane: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    Epoprostenol: (Moderate) Epoprostenol can have additive effects when administered with other antihypertensive agents, including beta-blockers. These effects can be used to therapeutic advantage, but dosage adjustments may be necessary.
    Ergonovine: (Major) Whenever possible, concomitant use of beta-blockers and ergot alkaloids should be avoided, since propranolol has been reported to potentiate the vasoconstrictive action of ergotamine. The risk of peripheral ischemia, resulting in cold extremities or gangrene, has been reported to be increased when ergot alkaloids are coadministered with selected beta-blockers, including propranolol, a beta-blocker commonly used for migraine prophylaxis. However, the precise mechanism of these interactions remains elusive. Additionally, because of the potential to cause coronary vasospasm, ergot alkaloids could antagonize the therapeutic effects of anti-anginal agents including beta-blockers; clinicians should keep in mind that ergot alkaloids are contraindicated for use in patients with coronary heart disease or hypertension.
    Ergotamine: (Moderate) Concurrent use of beta-blockers and ergot alkaloids should be approached with caution. Concomitant administration with beta-blockers may enhance the vasoconstrictive action of certain ergot alkaloids including dihydroergotamine, ergotamine, methylergonovine, and methysergide. The risk of peripheral ischemia, resulting in cold extremities or gangrene, has been reported to be increased when ergotamine or dihydroergotamine is coadministered with selected beta-blockers, including propranolol, a beta-blocker commonly used for migraine prophylaxis. However, the precise mechanism of these interactions remains elusive. Additionally, because of the potential to cause coronary vasospasm, these ergot alkaloids could antagonize the therapeutic effects of anti-anginal agents including beta-blockers; clinicians should keep in mind that ergot alkaloids are contraindicated for use in patients with coronary heart disease or hypertension.
    Ertugliflozin; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Estradiol Cypionate; Medroxyprogesterone: (Minor) Estrogens can induce fluid retention and may increase blood pressure in some patients; patients who are receiving antihypertensive agents concurrently with hormonal contraceptives should be monitored for antihypertensive effectiveness.
    Estradiol: (Minor) Estrogens can induce fluid retention and may increase blood pressure in some patients; patients who are receiving antihypertensive agents concurrently with hormonal contraceptives should be monitored for antihypertensive effectiveness.
    Etomidate: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    Exenatide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Felodipine: (Moderate) Coadministration of felodipine and labetalol can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Fenoldopam: (Major) Avoid concomitant use of fenoldopam with beta-blockers due to the risk of hypotension. If used together, monitor blood pressure frequently. Beta-blockers may inhibit the sympathetic reflex response to fenoldopam.
    Fingolimod: (Major) If possible, do not start fingolimod in a patient who is taking a drug that slows the heart rate or atrioventricular conduction such as beta-blockers. Use of these drugs during fingolimod initiation may be associated with severe bradycardia or heart block. Seek advice from the prescribing physician regarding the possibility to switch to drugs that do not slow the heart rate or atrioventricular conduction before initiating fingolimod. After the first fingolimod dose, overnight monitoring with continuous ECG in a medical facility is advised for patients who cannot stop taking drugs that slow the heart rate or atrioventricular conduction. Experience with fingolimod in patients receiving concurrent therapy with drugs that slow the heart rate or atrioventricular conduction is limited.
    Fish Oil, Omega-3 Fatty Acids (Dietary Supplements): (Moderate) High doses of fish oil supplements may produce a blood pressure lowering effect. It is possible that additive reductions in blood pressure may be seen when fish oils are used in a patient already taking antihypertensive agents.
    Flecainide: (Moderate) Pharmacologically, beta-blockers, like labetalol, cause AV nodal conduction depression and additive effects are possible when used in combination with flecainide. When used together, AV block can occur. During flecainide clinical trials, increased adverse events have not been reported in patients receiving combination therapy with beta-blockers and flecainide. However, patients should be monitored closely and the dose should be adjusted according to clinical response.
    Fludrocortisone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Flunisolide: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Fluorescein: (Moderate) Patients on beta-blockers are at an increased risk of adverse reaction when administered fluorescein injection. It is thought that beta-blockers may worsen anaphylaxis severity by exacerbating bronchospasm or by increasing the release of anaphylaxis mediators; alternately, beta-blocker therapy may make the patient more pharmacodynamically resistance to epinephrine rescue treatment.
    Fluticasone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Fluticasone; Salmeterol: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Fluticasone; Umeclidinium; Vilanterol: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Fluticasone; Vilanterol: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Food: (Major) Avoid administering marijuana and beta-blockers together as concurrent use may result in decreased beta-blocker efficacy. Marijuana is known to produce significant increases in heart rate and cardiac output lasting for 2-3 hours. Further, rare case reports of myocardial infarction and cardiac arrhythmias have been associated with marijuana use. These marijuana-induced cardiovascular effects may be detrimental to patients requiring treatment with beta-blockers; thus, coadministration of beta-blockers and marijuana should be avoided.
    Formoterol; Mometasone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Fospropofol: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    Galantamine: (Moderate) The increase in vagal tone induced by cholinesterase inhibitors, such as galantamine, may produce bradycardia or syncope. The vagotonic effect of galantamine may theoretically be increased when given with beta-blockers.
    General anesthetics: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    Ginger, Zingiber officinale: (Minor) In vitro studies have demonstrated the positive inotropic effects of certain gingerol constituents of ginger; but it is unclear if whole ginger root exhibits these effects clinically in humans. It is theoretically possible that excessive doses of ginger could affect the action of inotropes; however, no clinical data are available.
    Glipizide; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Glucagon: (Minor) A temporary increase in both blood pressure and pulse rate may occur following the administration of glucagon. Patients taking beta-blockers might be expected to have a greater increase in both pulse and blood pressure. Glucagon exerts positive inotropic and chronotropic effects and may, therefore, cause tachycardia and hypertension in some patients. The increase in blood pressure and pulse rate may require therapy in some patients with coronary artery disease.
    Glyburide; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Guanabenz: (Moderate) Guanabenz can have additive effects when administered with other antihypertensive agents, including beta-blockers. These effects can be used to therapeutic advantage, but dosage adjustments may be necessary.
    Guanfacine: (Moderate) Guanfacine can have additive effects when administered with other antihypertensive agents, including beta-blockers. These effects can be used to therapeutic advantage, but dosage adjustments may be necessary.
    Haloperidol: (Moderate) Haloperidol should be used cautiously with labetalol due to the possibility of additive hypotension.
    Halothane: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    Hydralazine; Isosorbide Dinitrate, ISDN: (Moderate) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as antihypertensive agents or other peripheral vasodilators. Patients should be monitored more closely for hypotension if nitroglycerin, including nitroglycerin rectal ointment, is used concurrently with any beta-blockers.
    Hydrocortisone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Icosapent ethyl: (Moderate) Beta-blockers may exacerbate hypertriglyceridemia and should be discontinued or changed to alternate therapy, if possible, prior to initiation of icosapent ethyl.
    Iloperidone: (Moderate) Secondary to alpha-blockade, iloperidone can produce vasodilation that may result in additive effects during concurrent use with antihypertensive agents. The potential reduction in blood pressure can precipitate orthostatic hypotension and associated dizziness, tachycardia, and syncope. If concurrent use of iloperidone and antihypertensive agents is necessary, patients should be counseled on measures to prevent orthostatic hypotension, such as sitting on the edge of the bed for several minutes prior to standing in the morning and rising slowly from a seated position. Close monitoring of blood pressure is recommended until the full effects of the combination therapy are known.
    Iloprost: (Moderate) Additive reductions in blood pressure may occur when inhaled iloprost is administered to patients receiving other antihypertensive agents.
    Incretin Mimetics: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Insulin Degludec; Liraglutide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Insulin Glargine; Lixisenatide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Insulins: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Intravenous Lipid Emulsions: (Moderate) High doses of fish oil supplements may produce a blood pressure lowering effect. It is possible that additive reductions in blood pressure may be seen when fish oils are used in a patient already taking antihypertensive agents.
    Iobenguane I 131: (Major) Discontinue labetalol for at least 5 half-lives before the administration of the dosimetry dose or a therapeutic dose of iobenguane I-131. Do not restart labetalol until at least 7 days after each iobenguane I-131 dose. Drugs that reduce catecholamine uptake or deplete catecholamine stores, such as labetalol, may interfere with iobenguane I-131 uptake into cells and interfere with dosimetry calculations resulting in altered iobenguane I-131 efficacy.
    Isocarboxazid: (Moderate) Additive hypotensive effects may be seen when monoamine oxidase inhibitors (MAOIs) are combined with antihypertensives. Careful monitoring of blood pressure is suggested during concurrent therapy of MAOIs with beta-blockers. Limited data suggest that bradycardia is worsened when MAOIs are administered to patients receiving beta-blockers. Although the sinus bradycardia observed was not severe, until more data are available, clinicians should use MAOIs cautiously in patients receiving beta-blockers. Patients should be instructed to rise slowly from a sitting position, and to report syncope or changes in blood pressure or heart rate to their health care provider.
    Isoflurane: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    Isosorbide Dinitrate, ISDN: (Moderate) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as antihypertensive agents or other peripheral vasodilators. Patients should be monitored more closely for hypotension if nitroglycerin, including nitroglycerin rectal ointment, is used concurrently with any beta-blockers.
    Isosorbide Mononitrate: (Moderate) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as antihypertensive agents or other peripheral vasodilators. Patients should be monitored more closely for hypotension if nitroglycerin, including nitroglycerin rectal ointment, is used concurrently with any beta-blockers.
    Isradipine: (Moderate) Although concomitant therapy with beta-blockers and isradipine is generally well tolerated and can even be beneficial in some cases, coadministration of these agents can induce excessive bradycardia or hypotension. Isradipine when used in combination with beta-blockers, especially in heart failure patients, can result in additive negative inotropic effects. Finally, angina has been reported when beta-adrenergic blocking agents are withdrawn abruptly when isradipine therapy is initiated. A gradual downward titration of the beta-adrenergic blocking agent dosage during initiation of isradipine therapy can minimize or eliminate this potential interaction. Patients should be monitored carefully, however, for excessive bradycardia, cardiac conduction abnormalities, or hypotension when these drugs are given together. In general, these reactions are more likely to occur with other non-dihydropyridine calcium channel blockers than with isradipine.
    Ivabradine: (Moderate) Monitor heart rate if ivabradine is coadministered with other negative chronotropes like beta-blockers. Most patients receiving ivabradine will receive concomitant beta-blocker therapy. Coadministration of drugs that slow heart rate increases the risk for bradycardia.
    Ketamine: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    Lacosamide: (Moderate) Use lacosamide with caution in patients taking concomitant medications that affect cardiac conduction, such as beta-blockers, because of the risk of AV block, bradycardia, or ventricular tachyarrhythmia. If use together is necessary, obtain an ECG prior to lacosamide initiation and after treatment has been titrated to steady-state. In addition, monitor patients receiving lacosamide via the intravenous route closely.
    Lanreotide: (Moderate) Concomitant administration of bradycardia-inducing drugs (e.g., beta-adrenergic blockers) may have an additive effect on the reduction of heart rate associated with lanreotide. Adjust the beta-blocker dose if necessary.
    Lasmiditan: (Moderate) Monitor heart rate if lasmiditan is coadministered with beta-blockers as concurrent use may increase the risk for bradycardia. Lasmiditan has been associated with lowering of heart rate. In a drug interaction study, addition of a single 200 mg dose of lasmiditan to a beta-blocker (propranolol) decreased heart rate by an additional 5 beats per minute.
    Levamlodipine: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Levobupivacaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Levodopa: (Moderate) Concomitant use of beta-blockers with levodopa can result in additive hypotensive effects.
    Levothyroxine: (Minor) Because thyroid hormones cause cardiac stimulation including increased heart rate and increased contractility, the effects of beta-blockers may be reduced by thyroid hormones. The reduction of effects may be especially evident when a patient goes from a hypothyroid to a euthyroid state or when excessive amounts of thyroid hormone is given to the patient.
    Levothyroxine; Liothyronine (Porcine): (Minor) Because thyroid hormones cause cardiac stimulation including increased heart rate and increased contractility, the effects of beta-blockers may be reduced by thyroid hormones. The reduction of effects may be especially evident when a patient goes from a hypothyroid to a euthyroid state or when excessive amounts of thyroid hormone is given to the patient.
    Levothyroxine; Liothyronine (Synthetic): (Minor) Because thyroid hormones cause cardiac stimulation including increased heart rate and increased contractility, the effects of beta-blockers may be reduced by thyroid hormones. The reduction of effects may be especially evident when a patient goes from a hypothyroid to a euthyroid state or when excessive amounts of thyroid hormone is given to the patient.
    Lidocaine: (Major) Drugs such as beta-blockers that decrease cardiac output reduce hepatic blood flow and thereby decrease lidocaine hepatic clearance. Also, opposing effects on conduction exist between lidocaine and beta-blockers while their effects to decrease automaticity may be additive. Propranolol has been shown to decrease lidocaine clearance and symptoms of lidocaine toxicity have been seen as a result of this interaction. This interaction is possible with other beta-blocking agents since most decrease hepatic blood flow. Monitoring of lidocaine concentrations is recommended during concomitant therapy with beta-blockers.
    Lidocaine; Prilocaine: (Major) Drugs such as beta-blockers that decrease cardiac output reduce hepatic blood flow and thereby decrease lidocaine hepatic clearance. Also, opposing effects on conduction exist between lidocaine and beta-blockers while their effects to decrease automaticity may be additive. Propranolol has been shown to decrease lidocaine clearance and symptoms of lidocaine toxicity have been seen as a result of this interaction. This interaction is possible with other beta-blocking agents since most decrease hepatic blood flow. Monitoring of lidocaine concentrations is recommended during concomitant therapy with beta-blockers. (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Linagliptin; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Linezolid: (Moderate) Linezolid is an antibiotic that is also a reversible, non-selective MAO inhibitor. Bradycardia may be worsened when MAO-inhibitors are co-administered to patients receiving beta-blockers. Use linezolid cautiously in patients receiving beta-blockers.
    Liothyronine: (Minor) Because thyroid hormones cause cardiac stimulation including increased heart rate and increased contractility, the effects of beta-blockers may be reduced by thyroid hormones. The reduction of effects may be especially evident when a patient goes from a hypothyroid to a euthyroid state or when excessive amounts of thyroid hormone is given to the patient.
    Liraglutide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Lithium: (Moderate) Beta-blockers have been used to treat lithium-induced tremor. Because tremor may be a sign of lithium toxicity and may be masked by the coadministration of beta-blockers, patients should be monitored for other clinical signs of lithium toxicity if these medications are taken concurrently. Other clinical signs of toxicity include: anorexia; visual impairment; drowsiness; muscular weakness; fasciculations or myoclonia; ataxia; dysarthria or slurred speech; stupor or coma; confusion or impaired cognition; seizures; and arrhythmias. Limited data suggest that using propranolol, even in low doses, with lithium can lead to bradycardia and syncope. In addition, lithium renal clearance has been shown to be lower when propranolol was coadministered. It is not clear if these effects are unique for propranolol or hold true for all beta-blockers. Until more data are known, clinicians should use beta-blockers with caution in patients receiving lithium. (Moderate) Moderate to significant dietary sodium changes, or changes in sodium and fluid intake, may affect lithium excretion. Systemic sodium chloride administration may result in increased lithium excretion and therefore, decreased serum lithium concentrations. In addition, high fluid intake may increase lithium excretion. For patients receiving sodium-containing intravenous fluids, symptom control and lithium concentrations should be carefully monitored. It is recommended that patients taking lithium maintain consistent dietary sodium consumption and adequate fluid intake during the initial stabilization period and throughout lithium treatment. Supplemental oral sodium and fluid should be only be administered under careful medical supervision.
    Lixisenatide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Lofexidine: (Major) Because both lofexidine and labetalol can cause hypotension and bradycardia, concurrent use should be avoided if possible. Patients being given lofexidine in an outpatient setting should be capable of and instructed on self-monitoring for hypotension, orthostasis, bradycardia, and associated symptoms. If clinically significant or symptomatic hypotension and/or bradycardia occur, the next dose of lofexidine should be reduced in amount, delayed, or skipped.
    Lopinavir; Ritonavir: (Moderate) Cardiac and neurologic events have been reported when ritonavir was concurrently administered with beta-blockers.
    Lovastatin; Niacin: (Moderate) Cutaneous vasodilation induced by niacin may become problematic if high-dose niacin is used concomitantly with other antihypertensive agents. This effect is of particular concern in the setting of acute myocardial infarction, unstable angina, or other acute hemodynamic compromise.
    Lurasidone: (Moderate) Due to the antagonism of lurasidone at alpha-1 adrenergic receptors, the drug may enhance the hypotensive effects of alpha-blockers and other antihypertensive agents. If concurrent use of lurasidone and antihypertensive agents is necessary, patients should be counseled on measures to prevent orthostatic hypotension, such as sitting on the edge of the bed for several minutes prior to standing in the morning and rising slowly from a seated position. Close monitoring of blood pressure is recommended until the full effects of the combination therapy are known.
    Magnesium Salicylate: (Moderate) Concurrent use of beta-blockers with aspirin and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Maprotiline: (Moderate) An increased incidence of labetalol-induced tremor has been reported in patients being treated concurrently with tricyclic antidepressants. Similar interactions would be expected with the related cyclic antidepressant maprotiline.
    Mefloquine: (Major) Concurrent use of mefloquine and beta blockers can result in ECG abnormalities or cardiac arrest.
    Meglitinides: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Mephobarbital: (Moderate) Barbiturates can enhance the hepatic metabolism of beta-blockers that are significantly metabolized by the liver. Beta-blockers that may be affected include labetalol. Clinicians should monitor patients for loss of beta-blockade.
    Mepivacaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Peripheral vasodilation may occur after use of mepivacaine. Thus, patients receiving antihypertensive agents may experience additive hypotensive effects. Blood concentrations of local anesthetics achieved after therapeutic doses are associated with minimal change in peripheral vascular resistance. Higher blood concentrations of local anesthetics may occur due to inadvertent intravascular administration or repeated doses.
    Mepivacaine; Levonordefrin: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Peripheral vasodilation may occur after use of mepivacaine. Thus, patients receiving antihypertensive agents may experience additive hypotensive effects. Blood concentrations of local anesthetics achieved after therapeutic doses are associated with minimal change in peripheral vascular resistance. Higher blood concentrations of local anesthetics may occur due to inadvertent intravascular administration or repeated doses.
    Mestranol; Norethindrone: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients; monitor patients receiving concurrent therapy to confirm that the desired antihypertensive effect is being obtained.
    Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Metformin; Repaglinide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Metformin; Rosiglitazone: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Metformin; Saxagliptin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Metformin; Sitagliptin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Methacholine: (Moderate) Beta-blockers may impair reversal of methacholine-induced bronchoconstriction with an inhaled rapid-acting beta-agonist.
    Methohexital: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension.
    Methylergonovine: (Moderate) Concurrent use of beta-blockers and ergot alkaloids should be approached with caution. Concomitant administration with beta-blockers may enhance the vasoconstrictive action of certain ergot alkaloids including dihydroergotamine, ergotamine, methylergonovine, and methysergide. The risk of peripheral ischemia, resulting in cold extremities or gangrene, has been reported to be increased when ergotamine or dihydroergotamine is coadministered with selected beta-blockers, including propranolol, a beta-blocker commonly used for migraine prophylaxis. However, the precise mechanism of these interactions remains elusive. Additionally, because of the potential to cause coronary vasospasm, these ergot alkaloids could antagonize the therapeutic effects of anti-anginal agents including beta-blockers; clinicians should keep in mind that ergot alkaloids are contraindicated for use in patients with coronary heart disease or hypertension.
    Methylprednisolone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Methysergide: (Moderate) Concurrent use of beta-blockers and ergot alkaloids should be approached with caution. Concomitant administration with beta-blockers may enhance the vasoconstrictive action of certain ergot alkaloids including dihydroergotamine, ergotamine, methylergonovine, and methysergide. The risk of peripheral ischemia, resulting in cold extremities or gangrene, has been reported to be increased when ergotamine or dihydroergotamine is coadministered with selected beta-blockers, including propranolol, a beta-blocker commonly used for migraine prophylaxis. However, the precise mechanism of these interactions remains elusive. Additionally, because of the potential to cause coronary vasospasm, these ergot alkaloids could antagonize the therapeutic effects of anti-anginal agents including beta-blockers; clinicians should keep in mind that ergot alkaloids are contraindicated for use in patients with coronary heart disease or hypertension.
    Milrinone: (Moderate) Concurrent administration of antihypertensive agents could lead to additive hypotension when administered with milrinone. Titrate milrinone dosage according to hemodynamic response.
    Mometasone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Nefazodone: (Minor) Although relatively infrequent, nefazodone may cause orthostatic hypotension in some patients; this effect may be additive with antihypertensive agents. Blood pressure monitoring and dosage adjustments of either drug may be necessary.
    Nesiritide, BNP: (Major) The potential for hypotension may be increased when coadministering nesiritide with antihypertensive agents.
    Neuromuscular blockers: (Moderate) Concomitant use of neuromuscular blockers and beta-blockers may prolong neuromuscular blockade.
    Niacin, Niacinamide: (Moderate) Cutaneous vasodilation induced by niacin may become problematic if high-dose niacin is used concomitantly with other antihypertensive agents. This effect is of particular concern in the setting of acute myocardial infarction, unstable angina, or other acute hemodynamic compromise.
    Niacin; Simvastatin: (Moderate) Cutaneous vasodilation induced by niacin may become problematic if high-dose niacin is used concomitantly with other antihypertensive agents. This effect is of particular concern in the setting of acute myocardial infarction, unstable angina, or other acute hemodynamic compromise.
    Nicardipine: (Moderate) Use nicardipine and labetalol with caution due to risk for additive negative effects on heart rate, AV conduction, and/or cardiac contractility.
    Nifedipine: (Moderate) In general, concomitant therapy of nifedipine with beta-blockers is well tolerated and can even be beneficial in some cases (i.e., inhibition of nifedipine-induced reflex tachycardia by beta-blockade). Negative inotropic and/or chronotropic effects can be additive when these drugs are used in combination. Finally, angina has been reported when beta-adrenergic blocking agents are withdrawn abruptly and nifedipine therapy is initiated. A gradual downward titration of the beta-adrenergic blocking agent dosage during initiation of nifedipine therapy may minimize or eliminate this potential interaction. Hypotension and impaired cardiac performance can occur during coadministration of nifedipine with beta-blockers, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis. Monitor clinical response during coadministration; adjustment of nifedipine dosage may be needed during concurrent beta-blocker therapy.
    Nimodipine: (Moderate) Nimodipine, a selective calcium-channel blocker, can enhance the antihypertensive effects of beta-blockers. Although often used together, concurrent use of calcium-channel blockers and beta-blockers may result in additive hypotensive, negative inotropic, and/or bradycardic effects in some patients.
    Nisoldipine: (Moderate) Concurrent use of nisoldipine with labetalol can be beneficial (i.e., inhibition of vasodilation-induced reflex tachycardia by beta-blockade); however, the additive negative inotropic and/or chronotropic effects can cause adverse effects, especially in patients with compromised ventricular function or conduction defects (e.g., sinus bradycardia or AV block).
    Nitrates: (Moderate) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as antihypertensive agents or other peripheral vasodilators. Patients should be monitored more closely for hypotension if nitroglycerin, including nitroglycerin rectal ointment, is used concurrently with any beta-blockers.
    Nitroglycerin: (Moderate) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as antihypertensive agents or other peripheral vasodilators. Patients should be monitored more closely for hypotension if nitroglycerin, including nitroglycerin rectal ointment, is used concurrently with any beta-blockers.
    Nitroprusside: (Moderate) Additive hypotensive effects may occur when nitroprusside is used concomitantly with other antihypertensive agents. Dosages should be adjusted carefully, according to blood pressure.
    Non-Ionic Contrast Media: (Moderate) Use caution when administering non-ionic contrast media to patients taking beta-blockers. Beta-blockers lower the threshold for and increase the severity of contrast reactions and reduce the responsiveness of treatment of hypersensitivity reactions with epinephrine.
    Nonsteroidal antiinflammatory drugs: (Moderate) If nonsteroidal anti-inflammatory drugs (NSAIDs) and an antihypertensive drug are concurrently used, carefully monitor the patient for signs and symptoms of renal insufficiency and blood pressure control. Doses of antihypertensive medications may require adjustment in patients receiving concurrent NSAIDs. NSAIDs, to varying degrees, have been associated with an elevation in blood pressure. This effect is most significant in patients receiving concurrent antihypertensive agents and long-term NSAID therapy. NSAIDs cause a dose-dependent reduction in prostaglandin formation, which may result in a reduction in renal blood flow leading to renal insufficiency and an increase in blood pressure that are often accompanied by peripheral edema and weight gain. Patients who rely upon renal prostaglandins to maintain renal perfusion may have acute renal blood flow reduction with NSAID usage. Elderly patients may be at increased risk of adverse effects from combined long-term NSAID therapy and antihypertensive agents, especially diuretics, due to age-related decreases in renal function and an increased risk of stroke and coronary artery disease.
    Octreotide: (Moderate) Dose adjustments in drugs such as beta-blockers and calcium-channel blockers which cause bradycardia and/or affect cardiac conduction may be necessary during octreotide therapy due to additive effects.
    Olanzapine: (Moderate) Olanzapine may induce orthostatic hypotension and thus enhance the effects of antihypertensive agents.
    Olanzapine; Fluoxetine: (Moderate) Olanzapine may induce orthostatic hypotension and thus enhance the effects of antihypertensive agents.
    Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Cardiac and neurologic events have been reported when ritonavir was concurrently administered with beta-blockers.
    Oxymetazoline: (Major) The vasoconstricting actions of oxymetazoline, an alpha adrenergic agonist, may reduce the antihypertensive effects produced by beta-blockers. If these drugs are used together, closely monitor for changes in blood pressure.
    Ozanimod: (Moderate) Ozanimod may cause bradycardia and AV-conduction delays, which may be enhanced with the concomitant use of beta-blockers. If a calcium channel blocker that slows heart rate/cardiac conduction is also prescribed with ozanimod and a beta-blocker, a cardiologist should be consulted due to the likelyhood of additive effects.
    Paliperidone: (Moderate) Paliperidone may cause orthostatic hypotension, thereby enhancing the hypotensive effects of antihypertensive agents. Orthostatic vital signs should be monitored in patients receiving paliperidone and beta-adrenergic blockers who are susceptible to hypotension.
    Pasireotide: (Major) Pasireotide may cause a decrease in heart rate. Closely monitor patients who are also taking drugs associated with bradycardia such as beta-blockers. Dose adjustments of beta-blockers may be necessary.
    Pentoxifylline: (Moderate) Pentoxifylline has been used concurrently with antihypertensive drugs (beta blockers, diuretics) without observed problems. Small decreases in blood pressure have been observed in some patients treated with pentoxifylline; periodic systemic blood pressure monitoring is recommended for patients receiving concomitant antihypertensives. If indicated, dosage of the antihypertensive agents should be reduced.
    Perindopril; Amlodipine: (Moderate) Coadministration of amlodipine and beta-blockers can reduce angina and improve exercise tolerance. When these drugs are given together, however, hypotension and impaired cardiac performance can occur, especially in patients with left ventricular dysfunction, cardiac arrhythmias, or aortic stenosis.
    Phenelzine: (Moderate) Additive hypotensive effects may be seen when monoamine oxidase inhibitors (MAOIs) are combined with antihypertensives. Careful monitoring of blood pressure is suggested during concurrent therapy of MAOIs with beta-blockers. Limited data suggest that bradycardia is worsened when MAOIs are administered to patients receiving beta-blockers. Although the sinus bradycardia observed was not severe, until more data are available, clinicians should use MAOIs cautiously in patients receiving beta-blockers. Patients should be instructed to rise slowly from a sitting position, and to report syncope or changes in blood pressure or heart rate to their health care provider.
    Phenoxybenzamine: (Moderate) Orthostatic hypotension may be more likely if beta-blockers are coadministered with alpha-blockers.
    Phentolamine: (Moderate) Orthostatic hypotension may be more likely if beta-blockers are coadministered with alpha-blockers.
    Pilocarpine: (Moderate) Systemically administered pilocarpine (e.g., when used for the treatment of xerostomia or xerophthalmia) should be administered with caution in patients taking beta-blockers because of the possibility of cardiac conduction disturbances. The risk of conduction disturbances with beta-blockers and ophthalmically administered pilocarpine is low.
    Pioglitazone; Metformin: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Ponesimod: (Moderate) Monitor for decreases in heart rate if concomitant use of ponesimod and beta-blockers is necessary. Consider a temporary interruption in beta-blocker therapy before initiating ponesimod in patients with a resting heart rate less than or equal to 55 bpm. Beta-blocker treatment can be initiated in patients receiving stable doses of ponesimod. Concomitant use of another beta-blocker with ponesimod resulted in a mean decrease in heart rate of 12.4 bpm after the first dose of ponesimod and 7.4 bpm after beginning maintenance ponesimod.
    Pramlintide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Prazosin: (Moderate) Orthostatic hypotension may be more likely if beta-blockers are coadministered with alpha-blockers.
    Prednisolone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Prednisone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Prilocaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Prilocaine; Epinephrine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Primidone: (Moderate) Barbiturates can enhance the hepatic metabolism of beta-blockers that are significantly metabolized by the liver, such as labetaolol. Clinicians should monitor patients for loss of beta-blockade.
    Procainamide: (Major) High or toxic concentrations of procainamide may prolong AV nodal conduction time or induce AV block; these effects could be additive with the pharmacologic actions of beta-blockers, like labetalol. In general, patients receiving combined therapy with procainamide and beta-blockers should be monitored for potential bradycardia, AV block, and/or hypotension.
    Procaine: (Minor) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Propafenone: (Major) Pharmacologically, beta-blockers, like labetalol, cause AV nodal conduction depression and additive effects are possible when used in combination with propafenone. When used together, AV block can occur. Patients should be monitored closely and the dose should be adjusted according to clinical response.
    Propofol: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    Quinidine: (Major) Quinidine may have additive effects (e.g., reduced heart rate, hypotension) on cardiovascular parameters when used together with beta-blockers, like labetalol. In general, patients receiving combined therapy should be monitored for potential hypotension, orthostasis, bradycardia and/or AV block, and heart failure. Reduce the beta-blocker dosage if necessary.
    Rasagiline: (Moderate) Additive hypotensive effects may be seen when monoamine oxidase inhibitors (MAOIs) are combined with antihypertensives. Careful monitoring of blood pressure is suggested during concurrent therapy of MAOIs with beta-blockers. Limited data suggest that bradycardia is worsened when MAOIs are administered to patients receiving beta-blockers. Although the sinus bradycardia observed was not severe, until more data are available, clinicians should use MAOIs cautiously in patients receiving beta-blockers. Patients should be instructed to rise slowly from a sitting position, and to report syncope or changes in blood pressure or heart rate to their health care provider.
    Remifentanil: (Moderate) The risk of significant hypotension and/or bradycardia during therapy with remifentanil may be increased in patients receiving beta-blockers or calcium-channel blockers due to additive hypotensive effects.
    Reserpine: (Moderate) Reserpine may have additive orthostatic hypotensive effects when used with beta-blockers due to catecholamine depletion. Beta-blockers may also interfere with reflex tachycardia, worsening the orthostasis. Patients treated concurrently with a beta-blocker and reserpine should be monitored closely for evidence of hypotension or marked bradycardia and associated symptoms (e.g., vertigo, syncope, postural hypotension).
    Risperidone: (Moderate) Risperidone may induce orthostatic hypotension and thus enhance the hypotensive effects of labetalol. Lower initial doses or slower dose titration of risperidone may be necessary in patients receiving labetalol concomitantly.
    Ritonavir: (Moderate) Cardiac and neurologic events have been reported when ritonavir was concurrently administered with beta-blockers.
    Rivastigmine: (Moderate) The increase in vagal tone induced by some cholinesterase inhibitors may produce bradycardia, hypotension, or syncope. The vagotonic effect of these drugs may theoretically be increased when given with other medications known to cause bradycardia such as beta-blockers.
    Ropivacaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents.
    Salsalate: (Moderate) Concurrent use of beta-blockers with salsalate and other salicylates may result in loss of antihypertensive activity due to inhibition of renal prostaglandins and thus, salt and water retention and decreased renal blood flow.
    Semaglutide: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Sevoflurane: (Major) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Beta-blockers may be continued during general anesthesia as long as the patient is monitored for cardiac depressant and hypotensive effects.
    SGLT2 Inhibitors: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Silodosin: (Moderate) During clinical trials with silodosin, the incidence of dizziness and orthostatic hypotension was higher in patients receiving concomitant antihypertensive treatment. Thus, caution is advisable when silodosin is administered with antihypertensive agents. In addition, increased concentrations of silodosin may occur if it is coadministered with carvedilol; exercise caution. Carvedilol is a P-glycoprotein (P-gp) inhibitor and silodosin is a P-gp substrate.
    Siponimod: (Moderate) Monitor for significant bradycardia with coadministration of siponimod and beta-blockers, as additive lowering effects on heart rate may occur; temporary interruption of beta-blocker treatment may be necessary prior to siponimod initiation. Beta-blocker treatment can be initiated in patients receiving stable doses of siponimod.
    Sufentanil: (Moderate) The incidence and degree of bradycardia and hypotension during induction with sufentanil may be increased in patients receiving beta-blockers.
    Sulfonylureas: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Sympathomimetics: (Minor) Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed in patients receiving a beta-blocker. Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Concurrent use increases the risk of unopposed alpha-adrenergic activity. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation.
    Tacrine: (Moderate) The increase in vagal tone induced by some cholinesterase inhibitors may produce bradycardia, hypotension, or syncope in some patients. The vagotonic effect of these drugs may be increased when given with other medications known to cause bradycardia such as beta-blockers. These interactions are pharmacodynamic in nature rather than pharmacokinetic.
    Tamsulosin: (Minor) Tamsulosin did not potentiate the hypotensive effects of atenolol. However, since the symptoms of orthostasis are reported more frequently in tamsulosin-treated vs. placebo patients, there is a potential risk of enhanced hypotensive effects when co-administered with antihypertensive agents
    Tasimelteon: (Moderate) Advise patients to administer the beta-blocker in the morning if tasimelteon is used concomitantly. Nighttime administration of a beta-blocker may reduce the efficacy of tasimelteon by decreasing the production of melatonin via inhibition of beta1 receptors.
    Terazosin: (Moderate) Orthostatic hypotension may be more likely if beta-blockers are coadministered with alpha-blockers.
    Tetrabenazine: (Moderate) Tetrabenazine may induce orthostatic hypotension and thus enhance the hypotensive effects of antihypertensive agents. Lower initial doses or slower dose titration of tetrabenazine may be necessary in patients receiving antihypertensive agents concomitantly.
    Tetracaine: (Moderate) Local anesthetics may cause additive hypotension in combination with antihypertensive agents. Use caution with the concomitant use of tetracaine and antihypertensive agents.
    Thalidomide: (Moderate) Thalidomide and other agents that slow cardiac conduction such as beta-blockers should be used cautiously due to the potential for additive bradycardia.
    Thiazolidinediones: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Thiopental: (Moderate) General anesthetics can potentiate the antihypertensive effects of beta-blockers and can produce prolonged hypotension. Patients receiving beta-blockers before or during surgery involving thiopental should be monitored closely for signs of heart failure.
    Thiothixene: (Moderate) Thiothixene should be used cautiously in patients receiving antihypertensive agents. Additive hypotensive effects are possible.
    Thyroid hormones: (Minor) Because thyroid hormones cause cardiac stimulation including increased heart rate and increased contractility, the effects of beta-blockers may be reduced by thyroid hormones. The reduction of effects may be especially evident when a patient goes from a hypothyroid to a euthyroid state or when excessive amounts of thyroid hormone is given to the patient.
    Tizanidine: (Moderate) Concurrent use of tizanidine with antihypertensive agents can result in significant hypotension. Caution is advised when tizanidine is to be used in patients receiving concurrent antihypertensive therapy.
    Tolvaptan: (Moderate) Coadministration of tolvaptan and hypertonic saline (e.g., 3% NaCl injection solution) is not recommended. The use of hypertonic sodium chloride in combination with tolvaptan may result in a too rapid correction of hyponatremia and increase the risk of osmotic demyelination (i.e., central pontine myelinolysis).
    Trandolapril; Verapamil: (Major) Intravenous labetalol is contraindicated with intravenous verapamil use in close proximity (within a few hours). Fatal cardiac arrests have occurred in patients receiving intravenous beta-blockers and intravenous calcium channel blockers. Use oral labetalol and oral verapamil with caution and close monitoring due to risk for additive negative effects on heart rate, AV conduction, and/or cardiac contractility. There have been reports of excess bradycardia and AV block, including complete heart block, when beta-blockers and verapamil have been used for the treatment of hypertension.
    Tranylcypromine: (Major) Avoid concomitant use of beta-blockers and tranylcypromine due to the risk of additive hypotension and/or severe bradycardia. Potential for this interaction persists for up to 10 days after discontinuation of tranylcypromine (or 4 to 5 half-lives after discontinuation of the beta-blocker). If a medication-free interval is not feasible, initiate therapy at the lowest appropriate dose and monitor blood pressure and heart rate closely.
    Trazodone: (Minor) Due to additive hypotensive effects, patients receiving antihypertensive agents concurrently with trazodone may have excessive hypotension. Decreased dosage of the antihypertensive agent may be required when given with trazodone.
    Triamcinolone: (Moderate) Concomitant use of systemic sodium chloride, especially at high doses, and corticosteroids may result in sodium and fluid retention. Assess sodium chloride intake from all sources, including intake from sodium-containing intravenous fluids and antibiotic admixtures. Carefully monitor sodium concentrations and fluid status if sodium-containing drugs and corticosteroids must be used together.
    Tricyclic antidepressants: (Moderate) An increased incidence of labetalol-induced tremor has been reported in patients being treated concurrently with tricyclic antidepressants (TCAs). the mechanism of the increase in tremor is not clear. In one study, labetalol caused a significant decrease (22% mean decrease) in the amount of imipramine metabolized to 2-hydroxyimipramine and from desipramine to 2-hydroxydesipramine (8% mean decrease). The AUCs of imipramine and desipramine were increased. Since these metabolic processes are dependent on the CYP2D6 isozyme, these data suggest that labetalol decreases the oral clearance of some TCAs by inhibiting this system.
    Verapamil: (Major) Intravenous labetalol is contraindicated with intravenous verapamil use in close proximity (within a few hours). Fatal cardiac arrests have occurred in patients receiving intravenous beta-blockers and intravenous calcium channel blockers. Use oral labetalol and oral verapamil with caution and close monitoring due to risk for additive negative effects on heart rate, AV conduction, and/or cardiac contractility. There have been reports of excess bradycardia and AV block, including complete heart block, when beta-blockers and verapamil have been used for the treatment of hypertension.
    Yohimbine: (Moderate) Yohimbine can increase blood pressure and therefore can antagonize the therapeutic action of antihypertensive agents. Use with particular caution in hypertensive patients with high or uncontrolled blood pressure.
    Ziprasidone: (Minor) Ziprasidone is a moderate antagonist of alpha-1 receptors and may cause orthostatic hypotension with or without tachycardia, dizziness, or syncope. Additive hypotensive effects are possible if ziprasidone is used concurrently with antihypertensive agents.

    PREGNANCY AND LACTATION

    Pregnancy

    Labetalol crosses the placenta. Extensive experience with the use of labetalol during human pregnancy, based on published interventional and observational studies, has not identified a drug-associated risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes. However, most studies reported the use of intravenous labetalol after 20 weeks gestation. These studies cannot definitely establish an absence of risk during pregnancy, as there have been inconsistent findings of intrauterine growth retardation, preterm birth, and perinatal mortality with maternal use of labetalol during pregnancy. In animal reproduction studies, oral administration of labetalol during organogenesis at doses up to 4- to 6-times the maximum recommended human dose (MRHD) resulted in no fetal malformation; however, fetal resorption was seen in both species (rats and rabbits) at doses approximating the MRHD. Monitor neonates born to mothers who are receiving labetalol during pregnancy for symptoms of hypotension, bradycardia, hypoglycemia, and respiratory depression and manage accordingly. Hypertension in pregnancy increases the maternal risk for preeclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section, post-partum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death. Monitor pregnant women with hypertension carefully monitored and manage accordingly.

    Consider the developmental and health benefits of breast-feeding along with the mother's clinical need for labetalol and any potential adverse effects on the breast-fed infant from labetalol or the underlying maternal condition. Small amounts of labetalol (approximately 0.004% of the maternal dose) are excreted in human milk. There are no data on the effects on the breast-fed infant or on milk production. Previous American Academy of Pediatrics (AAP) recommendations considered labetalol to be generally compatible with breast-feeding. Other experts consider labetalol to be compatible with breast-feeding in most infants; however, alternative agents may be preferred for the mothers of premature infants. Propranolol, another beta-blocker considered to be compatible with breast-feeding by previous AAP recommendations, may be a potential alternative for some patients.

    MECHANISM OF ACTION

    Labetalol is a combined selective, competitive alpha1-blocker and nonselective, competitive beta-blocker. Labetalol blocks beta1-receptors in the heart, beta2-receptors in bronchial and vascular smooth muscle, and alpha1-receptors in vascular smooth muscle. Its pharmacodynamic action is primarily mediated by beta-blockade, with an alpha- to beta-receptor activity ratio of 1:3 when given orally and 1:7 when given intravenously. The alpha1-blocking activity inhibits peripheral vasoconstriction and minimizes reductions in cardiac output often seen with beta-blockade. Labetalol reduces systemic vascular resistance without reducing total peripheral blood flow and has very little effect on cerebral circulation.[28106] [42601] [65609]

    PHARMACOKINETICS

    Labetalol is administered orally and intravenously. Labetalol is approximately 50% protein bound. Negligible amounts of the drug cross the blood-brain barrier. Metabolism occurs primarily through conjugation to glucuronide metabolites. These metabolites are excreted in the urine and feces. Approximately 55% to 60% of a dose appears in the urine as conjugates or unchanged drug within 24 hours of dosing. Total body clearance is 33 mL/kg/minute, and the plasma half-life is approximately 6 to 8 hours.[28106] [42601]
     
    Affected cytochrome P450 isoenzymes and drug transporters: none

    Oral Route

    Labetalol is completely absorbed from the gastrointestinal tract with peak plasma concentrations occurring within 1 to 2 hours after oral administration. Labetalol undergoes extensive first-pass metabolism; absolute bioavailability of labetalol when compared to an intravenous infusion is 25%. Absolute bioavailability is increased when administered with food. Despite first-pass metabolism, there is a linear relationship between oral doses of 100 to 3,000 mg and peak plasma concentrations. Peak effects occur within 2 to 4 hours of oral administration. Duration of effect depends on dose, lasting at least 8 hours after single oral doses of 100 mg and more than 12 hours after single oral doses of 300 mg. Approximately 70% of the maximum beta-blocking effect is present at 5 hours after oral dosing with a suggestion that 40% remains at 8 hours. Maximum, steady-state blood pressure response occurs within 24 to 72 hours upon oral, twice-daily dosing.[28106]

    Intravenous Route

    The maximum effect of each intravenous labetalol dose occurs within 5 minutes. An initial 0.25 mg/kg injection decreases blood pressure by an average of 11/7 mmHg. Additional injections of 0.5 mg/kg at 15-minute intervals up to a total cumulative dose of 1.75 mg/kg of labetalol caused further dose-related decreases in blood pressure. Blood pressure decreases by an average of 60/35 mmHg in patients receiving a continuous infusion (mean dose: 136 mg) over 2 to 3 hours. After drug discontinuation, blood pressure rises gradually and progressively approaching pretreatment values within an average of 16 to 18 hours.[42601]