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  • CLASSES

    Alpha-Blockers

    DEA CLASS

    Rx

    DESCRIPTION

    Oral alpha-1 adrenergic blocker
    Used to treat benign prostatic hypertrophy (BPH) in adult males
    Similar to tamsulosin, alfuzosin appears to be more specific for alpha-1a receptors than other alpha-blockers

    COMMON BRAND NAMES

    Uroxatral

    HOW SUPPLIED

    Alfuzosin/Uroxatral Oral Tab ER: 10mg

    DOSAGE & INDICATIONS

    For the symptomatic treatment of benign prostatic hyperplasia (BPH).
    Oral dosage
    Adult males

    10 mg PO once daily with food, with the same meal each day.

    For the treatment of erectile dysfunction (ED)† in combination with sildenafil in patients with lower urinary tract symptoms (LUTS) suggestive of BPH.
    Oral dosage
    Adult males

    10 mg PO once daily with food, with the same meal each day. In a pilot study, sildenafil (25 mg PO once daily at night) combined with alfuzosin (10 mg PO once daily) proved to be more effective than monotherapy with either agent for improving both voiding and sexual function in men with ED and LUTS suggestive of benign prostatic hyperplasia (BPH). Marked improvements in International Prostate Symptom Scores (IPSS) were noted with the combination compared to each agent alone. As expected, alfuzosin monotherapy significantly improved urinary frequency, nocturia, maximum urinary flow rate (Qmax), and postvoid residual urine (PVRU) volume whereas sildenafil showed minimal or no significant impact. Monotherapy with sildenafil showed significant improvements in erectile function whereas alfuzosin showed only a trend for improvement. The combination of sildenafil and alfuzosin, however, showed the most improvement in LUTS and erectile function compared to monotherapy with each agent.

    †Indicates off-label use

    MAXIMUM DOSAGE

    Adults

    10 mg/day PO.

    Geriatric

    10 mg/day PO.

    Adolescents

    Safety and efficacy have not been established.

    Children

    Safety and efficacy have not been established.

    Infants

    Not indicated.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Mild hepatic impairment (Child-Pugh class A): No dosage adjustment needed; use with caution.
    Moderate or severe hepatic impairment (Childs-Pugh class B or C): Do not use.

    Renal Impairment

    CrCl 30 mL/minute and greater: No dosage adjustment needed.
    CrCl less than 30 mL/minute: Limited safety data are available; therefore, administer alfuzosin with caution due to the potential for increased alfuzosin exposure.

    ADMINISTRATION

    Oral Administration
    Oral Solid Formulations

    Extended-release tablets:
    Swallow whole. Patients should not crush, cut or chew the extended-release tablets.
    Administer orally immediately after the same meal each day. Take with food. Do not take on an empty stomach.

    STORAGE

    Uroxatral:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    Alfuzosin is contraindicated in patients with known hypersensitivity to alfuzosin, such as urticaria and angioedema, or to any component of the commercial product.

    Hepatic disease

    Although the pharmacokinetics of alfuzosin have not been studied in patients with mild hepatic impairment, caution should be exercised when using the drug in such patients as blood concentrations of alfuzosin may be increased. Alfuzosin is contraindicated in patients with moderate or severe hepatic disease (Childs-Pugh classes B and C) because alfuzosin blood concentrations are increased in these patients. Similarly, alfuzosin use with potent CYP3A4 inhibitors is also contraindicated, since alfuzosin blood levels are increased.

    Angina, coronary artery disease, hypotension, orthostatic hypotension, syncope

    Orthostatic hypotension with or without symptoms (e.g., dizziness) may develop within a few hours following administration of alfuzosin. As with other alpha-blockers, there is a potential for syncope. Patients should be warned of the possible occurrence of such events and should avoid situations where injury could result should syncope occur. There may be an increased risk of hypotension and/or postural hypotension and syncope when taking alfuzosin during concomitant therapy with anti-hypertensive medication and/or nitrates. Alfuzosin should be discontinued if angina occurs or if it recurs or worsens in patients who are receiving therapy for coronary artery disease.

    Alcoholism, bradycardia, cardiac arrhythmias, cardiac disease, diabetes mellitus, females, heart failure, hypertension, hypocalcemia, hypokalemia, hypomagnesemia, long QT syndrome, malnutrition, myocardial infarction, QT prolongation, thyroid disease

    Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with a dose of alfuzosin 10 mg than with a dose of 40 mg, but the effect with alfuzosin 40 mg was not as great as the QT prolongation observed with therapeutic doses of moxifloxacin. Use alfuzosin with caution in patients with cardiac disease or other conditions that may increase the risk of QT prolongation including cardiac arrhythmias, congenital long QT syndrome, heart failure, bradycardia, myocardial infarction, hypertension, coronary artery disease, hypomagnesemia, hypokalemia, hypocalcemia, or in patients receiving medications known to prolong the QT interval or cause electrolyte imbalances. Females, elderly patients, patients with diabetes mellitus, thyroid disease, malnutrition, alcoholism, or hepatic dysfunction may also be at increased risk for QT prolongation.

    Renal failure, renal impairment

    Alfuzosin should be used cautiously in patients with severe renal disease (CrCl less than 30 mL/minute) including renal failure because limited safety data are available. Safety data in patients with mild to moderate renal impairment during clinical trials was similar to patients with normal renal function.

    Prostate cancer

    Prostate cancer and benign prostatic hyperplasia (BPH) cause many of the same symptoms. These two diseases frequently coexist. Therefore, patients thought to have BPH should be examined to rule out the presence of prostate cancer prior to starting treatment with alfuzosin.

    Surgery

    Alfuzosin should generally be used with caution in patients who will undergo general surgery; additive hypotension under general anesthesia may occur in rare instances with selective alpha blocker treatment.

    Ocular surgery

    Patients receiving or who have previously received treatment with alfuzosin or other alpha-1 blockers may be at risk for intraoperative floppy iris syndrome (IFIS) during surgery for cataracts (ocular surgery). Intraoperative floppy iris syndrome is a small pupil syndrome variant that is characterized by 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. The ophthalmologist should be prepared for possible modifications to their surgical technique such as the use of iris hooks, iris dilator rings, or viscoelastic substances. There does not appear to be a benefit of stopping alpha blocker therapy prior to cataract surgery.

    Priapism

    Rarely (probably less than 1 in 50,000), alfuzosin, like other alpha adrenergic blockers, has been associated with priapism (persistent painful penile erection unrelated to sexual activity). Priapism, if not treated promptly, can result in irreversible damage to the erectile tissue. Because this condition can lead to permanent impotence if not properly treated, patients should be advised about the seriousness of the condition. Males who have an erection lasting greater than 4 hours, whether painful or not, should seek emergency medical attention.

    Geriatric

    Geriatric patients should be monitored carefully for exaggerated hypotensive effects (e.g., first-dose effect) to alfuzosin. However, in clinical studies, no overall differences in safety or effectiveness were observed between elderly (65 years of age and older) and younger subjects. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). According to the OBRA guidelines, assessment of the underlying causes and identification of the type/category of urinary incontinence needs to be documented prior to or soon after the time of initiating treatment with a urinary incontinence medication. Alpha-blockers are not commonly used for urinary incontinence. These medications have specific and limited indications based on the cause and categorization of incontinence. Patients should be assessed periodically for medication effects on urinary incontinence as well as lower urinary tract symptoms and treatment tolerability.

    Pregnancy

    Alfuzosin is not indicated for use in females; therefore, no adequate well-controlled studies in pregnant women have been done to assess the safety of alfuzosin use during pregnancy. Alfuzosin was not teratogenic, embryotoxic or fetotoxic in rats at plasma exposure levels (based on AUC of unbound drug) up to 1,200-times the maximum recommended human dose (MRHD) of 10 mg/day. In rabbits administered up to 3-times the MRHD (based on body surface area) no embryofetal toxicity or teratogenicity was observed. Gestation was slightly prolonged in rats at exposure levels approximately 12-times the MRHD, but difficulties with parturition were not observed.

    Breast-feeding

    There is no known use of alfuzosin in breast-feeding mothers; it is not known whether alfuzosin distributes into breast milk.

    Children, infants

    Alfuzosin is only used to treat benign prostatic hyperplasia in men. It is not indicated for use in pediatric patients, and has not been studied in infants and children less than 2 years of age. The drug has been studied in pediatric patients 2 years and older but has not been proven effective. Efficacy of alfuzosin was not demonstrated in a randomized, double-blind, placebo-controlled, efficacy and safety trial conducted in 172 children and adolescents 2 to 16 years of age with elevated detrusor leak point pressure (LPP of 40 cm H2O or more) of neurologic origin treated with alfuzosin using pediatric formulations. The trial included a 12-week efficacy phase followed by a 40-week safety extension period. No statistically significant difference in the proportion of patients achieving a detrusor LPP of less than 40 cm H20 was observed between the alfuzosin and placebo groups. During the trial, the adverse reactions reported in 2% or more of alfuzosin-treated pediatric patients and at a higher incidence than in the placebo group were: pyrexia, headache, respiratory tract infection, cough, epistaxis and diarrhea. The adverse reactions reported for the whole 12-month trial period, which included the open-label extension, were similar in type and frequency to the reactions observed during the 12-week period.

    ADVERSE REACTIONS

    Severe

    atrial fibrillation / Early / Incidence not known
    bradycardia / Rapid / Incidence not known
    myocardial infarction / Delayed / Incidence not known
    angioedema / Rapid / Incidence not known
    toxic epidermal necrolysis / Delayed / Incidence not known

    Moderate

    impotence (erectile dysfunction) / Delayed / 1.0-2.0
    constipation / Delayed / 1.0-2.0
    priapism / Early / 0-1.0
    ejaculation dysfunction / Delayed / 0-1.0
    orthostatic hypotension / Delayed / 0.4-0.6
    hypotension / Rapid / 0.4-0.4
    confusion / Early / Incidence not known
    sinus tachycardia / Rapid / Incidence not known
    edema / Delayed / Incidence not known
    chest pain (unspecified) / Early / Incidence not known
    angina / Early / Incidence not known
    gastritis / Delayed / Incidence not known
    erythema / Early / Incidence not known
    jaundice / Delayed / Incidence not known
    cholestasis / Delayed / Incidence not known
    hepatitis / Delayed / Incidence not known
    QT prolongation / Rapid / Incidence not known
    floppy iris syndrome / Delayed / Incidence not known
    thrombocytopenia / Delayed / Incidence not known

    Mild

    dizziness / Early / 5.7-5.7
    headache / Early / 3.0-3.0
    infection / Delayed / 2.0-3.0
    fatigue / Early / 2.7-2.7
    pharyngitis / Delayed / 1.0-2.0
    sinusitis / Delayed / 1.0-2.0
    dyspepsia / Early / 1.0-2.0
    abdominal pain / Early / 1.0-2.0
    nausea / Early / 1.0-2.0
    asthenia / Delayed / 0-1.0
    insomnia / Early / 0-1.0
    diaphoresis / Early / 0-1.0
    drowsiness / Early / 0-1.0
    rash / Early / 0-1.0
    pruritus / Rapid / 0-1.0
    urticaria / Rapid / 0-1.0
    syncope / Early / 0.2-0.2
    vertigo / Early / Incidence not known
    rhinitis / Early / Incidence not known
    diarrhea / Early / Incidence not known
    vomiting / Early / Incidence not known
    flushing / Rapid / Incidence not known

    DRUG INTERACTIONS

    Abarelix: (Major) Since abarelix can cause QT prolongation, abarelix should be used cautiously with other drugs that are associated with QT prolongation, such as alfuzosin.
    Acebutolol: (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.
    Alpha-blockers: (Severe) The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects, therefore, alfuzosin should not be administered in combination with other alpha-blockers.
    Ambrisentan: (Moderate) The manufacturer warns that the combination of alfuzosin with antihypertensives, such as ambrisentan, has the potential to cause hypotension in some patients.
    Amiodarone: (Major) The concomitant use of amiodarone and other drugs known to prolong the QT interval should only be done after careful assessment of risks versus benefits. Amiodarone, a Class III antiarrhythmic agent, is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Although the frequency of TdP is less with amiodarone than with other Class III agents, amiodarone is still associated with a risk of TdP. Due to the extremely long half-life of amiodarone, a drug interaction is possible for days to weeks after discontinuation of amiodarone. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. In addition, alfuzosin is primarily metabolized by CYP3A4 hepatic enzymes and amiodarone is a CYP3A4 inhibitor. Concurrent use may increase systemic exposure to alfuzosin and further increase the risk for QT prolongation.
    Amitriptyline: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Amitriptyline; Chlordiazepoxide: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Amoxicillin; Clarithromycin; Lansoprazole: (Severe) Alfuzosin is contraindicated for use with clarithromycin due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Clarithromycin is a strong CYP3A4 inhibitor that is associated with an established risk for QT prolongation and torsade de pointes (TdP). Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Amoxicillin; Clarithromycin; Omeprazole: (Severe) Alfuzosin is contraindicated for use with clarithromycin due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Clarithromycin is a strong CYP3A4 inhibitor that is associated with an established risk for QT prolongation and torsade de pointes (TdP). Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Amphetamine; Dextroamphetamine Salts: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents. Due to the risk of unopposed alpha-adrenergic activity, amphetamines should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. In particular, amphetamines can inhibit the antihypertensive response to guanadrel, an adrenergic antagonist that causes depletion of norepinephrine in the synapse. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    Amprenavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Amyl Nitrite: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Anagrelide: (Major) Torsades de pointes (TdP) and ventricular tachycardia have been reported during post-marketing use of anagrelide. A cardiovascular examination, including an ECG, should be obtained in all patients prior to initiating anagrelide therapy. Monitor patients during anagrelide therapy for cardiovascular effects and evaluate as necessary. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with anagrelide include alfuzosin.
    Apomorphine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and apomorphine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Limited data indicate that QT prolongation is possible with apomorphine administration; the change in QTc interval is not significant in most patients receiving dosages within the manufacturer's guidelines. However, concurrent use with alfuzosin may increase the risk of QT prolongation.
    Aprepitant, Fosaprepitant: (Moderate) Increased alfuzosin exposure may occur with multi-day regimens of oral aprepitant, resulting in increased alfuzosin-related adverse reactions, including QT prolongation. Alfuzosin is a CYP3A4 substrate and aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor. When administered as a single oral or single intravenous dose, the inhibitory effect of aprepitant on CYP3A4 is weak and did not result in a clinically significant increase in the AUC of a sensitive substrate.
    Aripiprazole: (Major) QT prolongation has occurred during therapeutic use of aripiprazole and following overdose. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interva, which appears to be dose-dependent. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Aripiprazole may also be associated with a significant prolongation of the QTc interval in rare instances. Concurrent use may result in additive effects on the QT interval.
    Arsenic Trioxide: (Major) Arsenic trioxide administration is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Avoid the use of arsenic trioxide with other agents that may prolong the QT interval or increase the risk of torsades de pointes. If possible, drugs with potential to prolong the QT interval should be discontinued prior to beginning arsenic trioxide therapy. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg, but the effect with alfuzosin 40 mg was not as great as the QT prolongation observed with therapeutic doses of moxifloxacin. There have been no reports of torsades de pointes (TdP) in extensive post-marketing experience with alfuzosin outside the United States. There are no known pharmacokinetic/pharmacodynamic studies of the effect of other alpha-blockers on cardiac repolarization. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients with a known history of cardiac arrhythmias, QT prolongation (e.g., congenital or acquired QT prolongation), history of torsades de pointes, or patients who are taking medications known to prolong the QT interval.
    Artemether; Lumefantrine: (Major) Concurrent use of alfuzosin and artemether; lumefantrine should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Consider ECG monitoring alfuzosin must be used with or after artemether; lumefantrine treatment. Administration of artemether; lumefantrine is associated with prolongation of the QT interval. Alfuzosin has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. (Major) Concurrent use of alfuzosin and artemether; lumefantrine should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Consider ECG monitoring if alfuzosin must be used with or after artemether; lumefantrine treatment. Administration of artemether; lumefantrine is associated with prolongation of the QT interval. Alfuzosin has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Asenapine: (Major) Asenapine has been associated with QT prolongation. According to the manufacturer of asenapine, the drug should be avoided in combination with other agents also known to have this effect, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Atazanavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Atazanavir; Cobicistat: (Severe) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold. (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Atenolol: (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.
    Atenolol; Chlorthalidone: (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.
    Atomoxetine: (Major) QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Atomoxetine is considered a drug with a possible risk of torsade de pointes (TdP). Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with atomoxetine include alfuzosin.
    Avanafil: (Moderate) There is a risk of enhanced hypotensive effects in individual patients when an alpha blockers such as alfuzosin is co-administered with avanafil. Concurrent use of PDE5 inhibitors and alpha-blockers may lead to symptomatic hypotension in some patients. Patients should be stabilized on their alpha blocker therapy prior to starting avanafil, or, if already receiving an optimum dose of avanafil, the alpha blocker therapy should be started at the lowest possible dose.
    Azithromycin: (Major) Due to an increased risk for QT prolongation and torsade de pointes (TdP), caution is advised when administering alfuzosin with azithromycin. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Reports of QT prolongation and TdP have been spontaneously reported during azithromycin postmarketing surveillance. Concurrent use may increase the risk of QT prolongation.
    Bedaquiline: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering bedaquiline with alfuzosin. Bedaquiline has been reported to prolong the QT interval. Prior to initiating bedaquiline, obtain serum electrolyte concentrations and a baseline ECG. An ECG should also be performed at least 2, 12, and 24 weeks after starting bedaquiline therapy. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Bendroflumethiazide; Nadolol: (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.
    Bepridil: (Severe) Due to an increased risk of developing cardiac arrhythmias, avoid concomitant use of bepridil and alfuzosin. According to the manufacturer, bepridil is contraindicated for use with drugs that prolong the QT interval due to the risk of TdP, including antiarrhythmic agents which prolong the QT interval (e.g., Class IA antiarrhythmics and Class III antiarrhythmics) and tricyclic antidepressants. Bepridil inhibits the cardiac conduction system, and may slow conduction through the AV node, increasing the duration of the refractory period of the action potential. Bepridil administration has Class I antiarrhythmic properties and is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Patients receiving other drugs which have the potential for QT prolongation have an increased risk of developing proarrhythmias during bepridil therapy. In addition, based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg, but the effect with alfuzosin 40 mg was not as great as the QT prolongation observed with therapeutic doses of moxifloxacin. In a post-marketing study evaluating the effect of using alfuzosin with another drug with a comparable QT effect, an additive effect on the QT interval was observed but it was less than that observed with moxifloxacin alone. The study was not designed to make a direct statistical comparison between the drugs. There have been no reports of torsades de pointes (TdP) in extensive post-marketing experience with alfuzosin outside the United States. There are no known pharmacokinetic/pharmacodynamic studies of the effect of other alpha-blockers on cardiac repolarization. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients with a known history of cardiac arrhythmias, QT prolongation (e.g., congenital or acquired QT prolongation), history of torsades de pointes, or patients who are taking medications known to prolong the QT interval. In addition to avoiding concurrent drug interactions, the potential for TdP can be reduced by avoiding the use of QT prolonging drugs in patients at substantial risk for TdP. Examples of general risk factors for TdP include congenital long QT syndrome, female sex, elderly patients, significant bradycardia, hypokalemia, hypomagnesemia, and underlying cardiac disease (e.g., arrhythmias, cardiomyopathy, acute myocardial ischemia).
    Beta-adrenergic blockers: (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.
    Betaxolol: (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.
    Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Major) Potential QT prolongation has been reported in limited case reports with metronidazole. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with metronidazole include alfuzosin.
    Bismuth Subsalicylate; Metronidazole; Tetracycline: (Major) Potential QT prolongation has been reported in limited case reports with metronidazole. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with metronidazole include alfuzosin.
    Bisoprolol: (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.
    Bisoprolol; Hydrochlorothiazide, HCTZ: (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.
    Boceprevir: (Severe) Concurrent use of alfuzosin and boceprevir is contraindicated due to the potential for serious/life-threatening reactions. Boceprevir is a potent inhibitor of CYP3A4, which is responsible for alfuzosin metabolism. Coadministration may result in large increases in alfuzosin serum concentrations, which could cause adverse events such as hypotension.
    Brimonidine; Timolol: (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.
    Buprenorphine: (Major) Buprenorphine should be used cautiously and with close monitoring with should be used cautiously and with alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Buprenorphine has been associated with QT prolongation and has a possible risk of torsade de pointes (TdP). FDA-approved labeling for some buprenorphine products recommend avoiding use with Class 1A and Class III antiarrhythmic medications while other labels recommend avoiding use with any drug that has the potential to prolong the QT interval.
    Buprenorphine; Naloxone: (Major) Buprenorphine should be used cautiously and with close monitoring with should be used cautiously and with alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Buprenorphine has been associated with QT prolongation and has a possible risk of torsade de pointes (TdP). FDA-approved labeling for some buprenorphine products recommend avoiding use with Class 1A and Class III antiarrhythmic medications while other labels recommend avoiding use with any drug that has the potential to prolong the QT interval.
    Carteolol: (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.
    Carvedilol: (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.
    Ceritinib: (Major) Avoid coadministration of ceritinib and alfuzosin due to the potential for increased alfuzosin exposure; increased risk of QT prolongation is also possible. If coadministration cannot be avoided, periodically monitor electrolytes and ECGs; an interruption of therapy, dose reduction, or discontinuation of therapy may be necessary if QT prolongation occurs. Monitor for alfuzosin-related adverse reactions. Ceritinib is a CYP3A4 inhibitor that causes concentration-dependent prolongation of the QT interval. Alfuzosin is metabolized by CYP3A4 and, based on electrophysiology studies performed by the manufacturer, may also prolong the QT interval in a dose-dependent manner. The administration of alfuzosin is contraindicated with strong CYP3A4 inhibitors; the degree of CYP3A4 inhibition by ceritinib is unknown.
    Chloramphenicol: (Severe) Alfuzosin is contraindicated for use with chloramphenicol due to the potential for serious/life-threatening reactions, including hypotension. Alfuzosin is primarily metabolized by CYP3A4 hepatic enzymes; strong inhibitors of CYP3A4, such as chloramphenicol, block the metabolism of alfuzosin and increase systemic exposure to alfuzosin. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Chloroprocaine: (Major) Alfuzosin has a slight effect to prolong the QT interval, and should be used cautiously in combination with other medications known to prolong the QT interval, such as local anesthetics.
    Chloroquine: (Major) Chloroquine administration is associated with an increased risk of QT prolongation and torsades de pointes (TdP). The need to coadminister chloroquine with drugs known to prolong the QT interval should be done with a careful assessment of risks versus benefits and should be avoided when possible. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously with chloroquine include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Chlorpromazine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and chlorpromazine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Chlorpromazine, a phenothiazine, is associated with an established risk of QT prolongation and TdP. Concurrent use may result in additive QT prolongation.
    Cimetidine: (Moderate) Alfuzosin is extensively metabolized by hepatic enzymes. Administration of of cimetidine, an inhibitor of hepatic cytochrome P450, with alfuzosin may increase the serum concentration of alfuzosin.
    Ciprofloxacin: (Major) Due to an increased risk for QT prolongation and torsade de pointes (TdP), caution is advised when administering alfuzosin with ciprofloxacin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval, like ciprofloxacin.
    Cisapride: (Severe) Coadministration of cisapride and alfuzosin is contraindicated due to the potential for QT prolongation and torsades de pointes (TdP). QT prolongation and ventricular arrhythmias, including TdP and death, have been reported with cisapride. Alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Citalopram: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), concurrent use of alfuzosin and citalopram should be avoided if possible. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Citalopram causes dose-dependent QT interval prolongation. According to its manufacturer, concurrent use of citalopram with other drugs that prolong the QT interval is not recommended. If concurrent therapy is considered essential, ECG monitoring is recommended.
    Clarithromycin: (Severe) Alfuzosin is contraindicated for use with clarithromycin due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Clarithromycin is a strong CYP3A4 inhibitor that is associated with an established risk for QT prolongation and torsade de pointes (TdP). Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Clomipramine: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Clozapine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and clozapine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Treatment with clozapine has been associated with QT prolongation, TdP, cardiac arrest, and sudden death. The manufacturer of clozapine recommends caution during concurrent use with medications known to cause QT prolongation.
    Cobicistat: (Severe) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Cobicistat; Elvitegravir; Emtricitabine; Tenofovir Alafenamide: (Severe) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Cobicistat; Elvitegravir; Emtricitabine; Tenofovir Disoproxil Fumarate: (Severe) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Codeine; Phenylephrine; Promethazine: (Moderate) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval; use these drugs with caution and with close clinical monitoring. Promethazine carries a possible risk of QT prolongation.
    Codeine; Promethazine: (Moderate) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval; use these drugs with caution and with close clinical monitoring. Promethazine carries a possible risk of QT prolongation.
    Conivaptan: (Severe) Alfuzosin is contraindicated for use with conivaptan due to the potential for serious/life-threatening reactions, including hypotension. Treatment with alfuzosin may be initiated no sooner than 1 week after completion of conivaptan therapy. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; conivaptan is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Crizotinib: (Major) Avoid coadministration of crizotinib with alfuzosin due to the risk of QT prolongation; increased alfuzosin exposure may also occur. If concomitant use is unavoidable, monitor ECGs for QT prolongation and monitor electrolytes; an interruption of therapy, dose reduction, or discontinuation of therapy may be necessary for crizotinib if QT prolongation occurs. Also monitor for evidence of alfuzosin-related adverse effects (e.g., hypotension). Alfuzosin is a CYP3A4 substrate that, based on electrophysiology studies performed by the manufacturer, may prolong the QT interval in a dose-dependent manner. Crizotinib is a moderate CYP3A inhibitor that has also been associated with concentration-dependent QT prolongation. Coadministration with a moderate CYP3A4 inhibitor increased the alfuzosin AUC by 1.3-fold.
    Darunavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Darunavir; Cobicistat: (Severe) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold. (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Severe) Alfuzosin is contraindicated for use with cobicistat due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; cobicistat is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold. (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Dasatinib: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and dasatinib should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. In vitro studies have shown that dasatinib has the potential to prolong the QT interval. Caution is advised when coadministered with other drugs that prolong the QT interval.
    Degarelix: (Major) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously with alfuzosin include degarelix.
    Delavirdine: (Severe) Alfuzosin is contraindicated for use with delavirdine due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; delavirdine is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Desflurane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Desipramine: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Deutetrabenazine: (Major) For patients taking a deutetrabenazine dosage more than 24 mg/day with alfuzosin, assess the QTc interval before and after increasing the dosage of either medication. Clinically relevant QTc prolongation may occur with deutetrabenazine. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Dextromethorphan; Promethazine: (Moderate) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval; use these drugs with caution and with close clinical monitoring. Promethazine carries a possible risk of QT prolongation.
    Dextromethorphan; Quinidine: (Major) Alfuzosin should be used cautiously with quinidine. Quinidine administration is associated with QT prolongation and torsades de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Diltiazem: (Major) Alfuzosin and diltiazem may have additive vasodilatory actions; concurrent use of these agents can result in hypotension. Alfuzosin is primarily metabolized by the CYP3A4 hepatic enzyme. Diltiazem, a moderately potent CYP3A4 inhibitor, increases the Cmax and AUC of alfuzosin; alfuzosin increases both the Cmax and AUC of diltiazem, however, no changes in blood pressure are reported.
    Disopyramide: (Major) Alfuzosin should be used cautiously and with close monitoring with disopyramide. Disopyramide administration is associated with QT prolongation and torsades de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Dofetilide: (Severe) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Dofetilide, a Class III antiarrhythmic agent, is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Because of the potential for TdP, concurrent use is contraindicated.
    Dolasetron: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), dolasetron and alfuzosin should be used together cautiously. Dolasetron has been associated with a dose-dependant prolongation in the QT, PR, and QRS intervals on an electrocardiogram. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Concomitant use may increase the risk for QT prolongation.
    Dolutegravir; Rilpivirine: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Donepezil: (Moderate) Case reports indicate that QT prolongation and torsade de pointes (TdP) can occur during donepezil therapy. Donepezil is considered a drug with a known risk of TdP. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with donepezil include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Donepezil; Memantine: (Moderate) Case reports indicate that QT prolongation and torsade de pointes (TdP) can occur during donepezil therapy. Donepezil is considered a drug with a known risk of TdP. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with donepezil include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Dorzolamide; Timolol: (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.
    Doxazosin: (Severe) The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects, therefore, alfuzosin should not be administered in combination with other alpha-blockers.
    Doxepin: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Dronedarone: (Severe) Concurrent use of dronedarone and alfuzosin is contraindicated. Dronedarone administration is associated with a dose-related increase in the QTc interval. The increase in QTc is approximately 10 milliseconds at doses of 400 mg twice daily (the FDA-approved dose) and up to 25 milliseconds at doses of 1600 mg twice daily. Although there are no studies examining the effects of dronedarone in patients receiving other QT prolonging drugs, coadministration of such drugs may result in additive QT prolongation. The concomitant use of dronedarone with other drugs that prolong the QTc may induce Torsade de Pointes (TdP) and is contraindicated. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Droperidol: (Major) Droperidol should be administered with extreme caution to patients receiving other agents that may prolong the QT interval. Droperidol administration is associated with an established risk for QT prolongation and torsades de pointes (TdP). Any drug known to have potential to prolong the QT interval should not be coadministered with droperidol. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously with droperidol include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Duvelisib: (Moderate) Monitor for evidence of alfuzosin-related adverse effects including hypotension and QT prolongation if coadministered with duvelisib. Increased alfuzosin exposure may occur. Alfuzosin is a CYP3A4 substrate. duvelisib is a moderate CYP3A4 inhibitor. Coadministration of another moderate CYP3A4 inhibitor increased the alfuzosin AUC by 1.3-fold.
    Efavirenz: (Major) Although data are limited, coadministration of efavirenz and alfuzosin may increase the risk for QT prolongation and torsade de pointes (TdP). QT prolongation has been observed with use of efavirenz. A slight prolonging effect on the QT interval has also been observed during alfuzosin electrophysiology studies. Alfuzosin-induced QT prolongation appears to be less with 10 mg than with 40 mg. In addition, efavirenz may induce the CYP3A4 metabolism of alfuzosin, potentially reducing the efficacy of alfuzosin by decreasing its systemic exposure.
    Efavirenz; Emtricitabine; Tenofovir: (Major) Although data are limited, coadministration of efavirenz and alfuzosin may increase the risk for QT prolongation and torsade de pointes (TdP). QT prolongation has been observed with use of efavirenz. A slight prolonging effect on the QT interval has also been observed during alfuzosin electrophysiology studies. Alfuzosin-induced QT prolongation appears to be less with 10 mg than with 40 mg. In addition, efavirenz may induce the CYP3A4 metabolism of alfuzosin, potentially reducing the efficacy of alfuzosin by decreasing its systemic exposure.
    Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Major) Although data are limited, coadministration of efavirenz and alfuzosin may increase the risk for QT prolongation and torsade de pointes (TdP). QT prolongation has been observed with use of efavirenz. A slight prolonging effect on the QT interval has also been observed during alfuzosin electrophysiology studies. Alfuzosin-induced QT prolongation appears to be less with 10 mg than with 40 mg. In addition, efavirenz may induce the CYP3A4 metabolism of alfuzosin, potentially reducing the efficacy of alfuzosin by decreasing its systemic exposure.
    Elbasvir; Grazoprevir: (Moderate) Administering alfuzosin with elbasvir; grazoprevir may result in elevated alfuzosin plasma concentrations. Alfuzosin is a substrate of CYP3A; grazoprevir is a weak CYP3A inhibitor. If these drugs are used together, closely monitor for signs of adverse events.
    Eliglustat: (Major) Eliglustat is predicted to cause PR, QRS, and/or QT prolongation at significantly elevated plasma concentrations. Drugs with a possible risk for QT prolongation and torsade de pointes (TdP) that should be used cautiously and with close monitoring with eliglustat include alfuzosin.
    Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Emtricitabine; Rilpivirine; Tenofovir disoproxil fumarate: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Enalapril; Felodipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Encorafenib: (Major) Avoid coadministration of encorafenib and alfuzosin due to QT prolongation. If concurrent use cannot be avoided, monitor ECGs for QT prolongation and monitor electrolytes; correct hypokalemia and hypomagnesemia prior to treatment. Encorafenib is associated with dose-dependent prolongation of the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Enflurane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Eribulin: (Major) Eribulin has been associated with QT prolongation. If eribulin and another drug that prolongs the QT interval, such as alfuzosin, must be coadministered, ECG monitoring is recommended; closely monitor the patient for QT interval prolongation.
    Erythromycin: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and erythromycin should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Erythromycin administration is associated with QT prolongation and TdP. In addition, coadministration of erythromycin, a CYP3A4 inhibitor, with alfuzosin, a CYP3A4 substrate, may result in elevated alfuzosin plasma concentrations.
    Erythromycin; Sulfisoxazole: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and erythromycin should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Erythromycin administration is associated with QT prolongation and TdP. In addition, coadministration of erythromycin, a CYP3A4 inhibitor, with alfuzosin, a CYP3A4 substrate, may result in elevated alfuzosin plasma concentrations.
    Escitalopram: (Major) Escitalopram has been associated with QT prolongation. Coadministration with other drugs that have a possible risk for QT prolongation and torsade de pointes (TdP), such as alfuzosin, should be done with caution and close monitoring.
    Esmolol: (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.
    Ezogabine: (Major) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously with alfuzosin include ezogabine.
    Felodipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Fingolimod: (Major) Fingolimod initiation results in decreased heart rate and may prolong the QT interval. After the first fingolimod dose, overnight monitoring with continuous ECG in a medical facility is advised for patients taking QT prolonging drugs with a known risk of torsades de pointes (TdP). Fingolimod has not been studied in patients treated with drugs that prolong the QT interval, but drugs that prolong the QT interval have been associated with cases of TdP in patients with bradycardia. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously with fingolimod include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Flecainide: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering alfuzosin with flecainide. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight QT prolonging effect. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Flecainide, a Class IC antiarrhythmic, is also associated with a possible risk for QT prolongation and/or TdP; although, the increase in QT interval is largely due to prolongation of the QRS interval. Causality for TdP has not been established for flecainide.
    Fluconazole: (Severe) Due to the risk of life-threatening arrhythmias such as torsade de pointes (TdP), coadministration of fluconazole with drugs that both prolong the QT interval and are CYP3A4 substrates, such as alfuzosin, is contraindicated. Fluconazole has been associated with QT prolongation and rare cases of TdP. Additonally, fluconazole is an inhibitor of CYP3A4. Coadministration may result in elevated plasma concentrations of alfuzosin, causing an increased risk for adverse events, such as QT prolongation.
    Fluoxetine: (Major) Because QT prolongation and torsade de pointes (TdP) have been reported in patients treated with fluoxetine, the manufacturer recommends caution when using fluoxetine with other drugs that prolong the QT interval. Drugs with a possible risk for QT prolongation and TdP include alfuzosin.
    Fluoxetine; Olanzapine: (Major) Because QT prolongation and torsade de pointes (TdP) have been reported in patients treated with fluoxetine, the manufacturer recommends caution when using fluoxetine with other drugs that prolong the QT interval. Drugs with a possible risk for QT prolongation and TdP include alfuzosin. (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and olanzapine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval. Therefore, caution is advised when administering olanzapine with drugs having an established causal association with QT prolongation and TdP.
    Fluphenazine: (Minor) Due to a possible risk for QT prolongation use these drugs together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Fluphenazine, a phenothiazine, is associated with a possible risk for QT prolongation.
    Fluvoxamine: (Major) There may be an increased risk for QT prolongation and torsade de pointes (TdP) during concurrent use of fluvoxamine and alfuzosin. Coadminister with caution. QT prolongation and torsade de pointes (TdP) has been reported during fluvoxamine postmarketing use. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Also, alfuzosin is primarily metabolized by CYP3A4 and inhibitors of CYP3A4, such as fluvoxamine, are expected to inhibit alfuzosin metabolism and increase systemic exposure to alfuzosin.
    Food: (Moderate) Alfuzosin extended-release tablets should be taken with food at the same time each day. Alfuzosin absolute bioavailability is 49 percent under fed conditions; under fasting conditions, the extent of absorption is 50 percent lower.
    Fosamprenavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Foscarnet: (Major) When possible, avoid concurrent use of foscarnet with other drugs known to prolong the QT interval, such as alfuzosin. Foscarnet has been associated with postmarketing reports of both QT prolongation and torsade de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. If these drugs are administered together, obtain an electrocardiogram and electrolyte concentrations before and periodically during treatment.
    Gemifloxacin: (Major) Due to an increased risk for QT prolongation and torsade de pointes (TdP), caution is advised when administering gemifloxacin with alfuzosin. Gemifloxacin may prolong the QT interval in some patients. The maximal change in the QTc interval occurs approximately 5 to 10 hours following oral administration of gemifloxacin. The likelihood of QTc prolongation may increase with increasing dose of the drug; therefore, the recommended dose should not be exceeded especially in patients with renal or hepatic impairment where the Cmax and AUC are slightly higher. Alfuzosin has a slight effect to prolong the QT interval based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Gemtuzumab Ozogamicin: (Major) Use gemtuzumab ozogamicin and alfuzosin together with caution due to the potential for additive QT interval prolongation and risk of torsade de pointes (TdP). If these agents are used together, obtain an ECG and serum electrolytes prior to the start of gemtuzumab and as needed during treatment. Although QT interval prolongation has not been reported with gemtuzumab, it has been reported with other drugs that contain calicheamicin. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Glasdegib: (Major) Avoid coadministration of glasdegib with alfuzosin due to the potential for additive QT prolongation. If coadministration cannot be avoided, monitor patients for increased risk of QT prolongation with increased frequency of ECG monitoring. Glasdegib therapy may result in QT prolongation and ventricular arrhythmias including ventricular fibrillation and ventricular tachycardia. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Goserelin: (Major) Alfuzosin should be used cautiously and with close monitoring with goserelin. Androgen deprivation therapy (e.g., goserelin) prolongs the QT interval; the risk may be increased with the concurrent use of drugs that may prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Granisetron: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), granisetron and alfuzosin should be used together cautiously. Granisetron has been associated with QT prolongation. According to the manufacturer, use of granisetron with drugs known to prolong the QT interval or are arrhythmogenic, may result in clinical consequences. Based on electrophysiology studies performed by its manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Grapefruit juice: (Severe) Instruct patients not to consume grapefruit or grapefruit juice while taking alfuzosin. Grapefruit may increase alfuzosin exposure resulting in serious/life-threatening reactions, including hypotension. Alfuzosin is primarily metabolized by CYP3A4; grapefruit is a strong CYP3A4 inhibitor.
    Halofantrine: (Major) Halofantrine is considered to be associated with an increased risk for QT prolongation and torsades de pointes. The need to co-administer halofantrine with drugs known to prolong the QT interval, such as alfuzosin, should be done with a careful assessment of risks versus benefits, and should be avoided when possible.
    Halogenated Anesthetics: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Haloperidol: (Major) QT prolongation and torsade de pointes (TdP) have been observed during haloperidol treatment. Excessive doses (particularly in the overdose setting) or IV administration of haloperidol may be associated with a higher risk of QT prolongation. According to the manufacturer of haloperidol, caution is advisable when prescribing the drug concurrently with medications known to prolong the QT interval, including alfuzosin.
    Halothane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Histrelin: (Major) Consider periodic monitoring of EGCs for QT prolongation and monitor electrolytes if coadministration of histrelin and alfuzosin is necessary; correct any electrolyte abnormalities. Androgen deprivation therapy (e.g., histrelin) prolongs the QT interval; the risk may be increased with the concurrent use of drugs that may prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Hydralazine; Isosorbide Dinitrate, ISDN: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Hydrochlorothiazide, HCTZ; Metoprolol: (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.
    Hydrochlorothiazide, HCTZ; Propranolol: (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.
    Hydroxychloroquine: (Major) Avoid coadministration of hydroxychloroquine and alfuzosin. Hydroxychloroquine increases the QT interval and should not be administered with other drugs known to prolong the QT interval. Ventricular arrhythmias and torsade de pointes have been reported with the use of hydroxychloroquine. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Hydroxyzine: (Major) Post-marketing data indicate that hydroxyzine causes QT prolongation and Torsade de Pointes (TdP). Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with hydroxyzine include alfuzosin.
    Ibutilide: (Major) Ibutilide administration can cause QT prolongation and torsades de pointes (TdP); proarrhythmic events should be anticipated. The potential for proarrhythmic events with ibutilide increases with the coadministration of other drugs that prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Idelalisib: (Severe) Coadministration of alfuzosin and idelalisib is contraindicated due to increased alfuzosin exposure. Idelalisib is a strong CYP3A4 inhibitor. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Iloperidone: (Major) Iloperidone has been associated with QT prolongation; however, torsade de pointes has not been reported. According to the manufacturer, since iloperidone may prolong the QT interval, it should be avoided with other agents also known to have this effect, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Iloprost: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Imatinib: (Moderate) Alfuzosin is primarily metabolized by CYP3A4 hepatic enzymes; inhibitors of CYP3A4, such as imatinib, are expected to inhibit alfuzosin metabolism and increase systemic exposure to alfuzosin.
    Imipramine: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Indapamide: (Moderate) The effects of indapamide may be additive when administered with other antihypertensive agents or diuretics. This may be desirable, but occasionally orthostatic hypotension may occur. Decreased indapamide dosages may be necessary during concomitant use.
    Indinavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Inotuzumab Ozogamicin: (Major) Avoid coadministration of inotuzumab ozogamicin with alfuzosin due to the potential for additive QT interval prolongation and risk of torsade de pointes (TdP). If coadministration is unavoidable, obtain an ECG and serum electrolytes prior to the start of treatment, after treatment initiation, and periodically during treatment. Inotuzumab has been associated with QT interval prolongation. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Isavuconazonium: (Moderate) Concomitant use of isavuconazonium with alfuzosin may result in increased serum concentrations of alfuzosin. Alfuzosin is a substrate of the hepatic isoenzyme CYP3A4; isavuconazole, the active moiety of isavuconazonium, is a moderate inhibitor of this enzyme. Caution and close monitoring are advised if these drugs are used together.
    Isoflurane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Isosorbide Dinitrate, ISDN: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Isosorbide Mononitrate: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Isradipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Itraconazole: (Severe) Alfuzosin is contraindicated for use during itraconazole therapy and is not recommended for 2 weeks after completion of itraconazole therapy. Concurrent use of itraconazole (strong CYP3A4 inhibitor) increases alfuzosin (CYP3A4 substrate) exposure. Both alfuzosin and itraconazole are also associated with QT prolongation; coadministration may increase this risk.
    Ivosidenib: (Major) Avoid coadministration of ivosidenib with alfuzosin due to an increased risk of QT prolongation. If concomitant use is unavoidable, monitor ECGs for QTc prolongation and monitor electrolytes; correct any electrolyte abnormalities as clinically appropriate. An interruption of therapy and dose reduction of ivosidenib may be necessary if QT prolongation occurs. Prolongation of the QTc interval and ventricular arrhythmias have been reported in patients treated with ivosidenib. Alfuzosin may prolong the QT interval in a dose-dependent manner.
    Ketoconazole: (Severe) Concomitant use of alfuzosin and ketoconazole is contraindicated. Both alfuzosin and ketoconazole are associated with QT prolongation; coadministration may increase this risk. In addition, coadministration of ketoconazole (a potent CYP3A4 inhibitor) with alfuzosin (a CYP3A4 substrate) results in elevated alfuzosin plasma concentrations and may increase the risk for adverse events, including QT prolongation. In one study, repeated doses of ketoconazole (400 mg) increased alfuzosin Cmax by 2.3-fold and AUC by 3.2-fold after a single alfuzosin dose. At a lower ketoconazole dose (200 mg) the Cmax and AUC of alfuzosin were increased by 2.1-fold and 2.5-fold, respectively.
    Labetalol: (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.
    Lapatinib: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and lapatinib should be used together cautiously. Lapatinib can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Lenvatinib: (Major) Avoid coadministration of lenvatinib with alfuzosin due to the risk of QT prolongation. Prolongation of the QT interval has been reported with lenvatinib therapy. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Lesinurad: (Moderate) Lesinurad may decrease the systemic exposure and therapeutic efficacy of alfuzosin; monitor for potential reduction in efficacy. Alfuzosin is a CYP3A substrate, and lesinurad is a weak CYP3A inducer.
    Lesinurad; Allopurinol: (Moderate) Lesinurad may decrease the systemic exposure and therapeutic efficacy of alfuzosin; monitor for potential reduction in efficacy. Alfuzosin is a CYP3A substrate, and lesinurad is a weak CYP3A inducer.
    Letermovir: (Moderate) Coadministration of alfuzosin with letermovir may increase alfuzosin exposure and risk for adverse events. Concurrent use is contraindicated if the patient is also receiving cyclosporine because the magnitude of the interaction may be amplified. Alfuzosin is a substrate of CYP3A4. Letermovir is a moderate CYP3A4 inhibitor. The combined effect of letermovir and cyclosporine on CYP3A4 substrates may be similar to a strong CYP3A4 inhibitor. Coadministration of a strong CYP3A4 inhibitor with alfuzosin increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Leuprolide: (Major) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Androgen deprivation therapy (e.g., leuprolide) prolongs the QT interval; the risk may be increased with the concurrent use of drugs that may prolong the QT interval. Use these drugs together cautiously and with close monitoring.
    Leuprolide; Norethindrone: (Major) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Androgen deprivation therapy (e.g., leuprolide) prolongs the QT interval; the risk may be increased with the concurrent use of drugs that may prolong the QT interval. Use these drugs together cautiously and with close monitoring.
    Levobetaxolol: (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.
    Levobunolol: (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.
    Levofloxacin: (Major) Concurrent use of alfuzosin and levofloxacin should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Levofloxacin has been associated with prolongation of the QT interval and infrequent cases of arrhythmia. Additionally, rare cases of TdP have been spontaneously reported during postmarketing surveillance in patients receiving levofloxacin. Alfuzosin has a slight prolongation effect to the QT interval, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Levomethadyl: (Severe) Levomethadyl is associated with an established risk of QT prolongation and/or torsades de pointes and is contraindicated in combination with other agents that may prolong the QT interval, such as alfuzosin.
    Lithium: (Major) Lithium should be used cautiously and with close monitoring with alfuzosin. Lithium has been associated with QT prolongation. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Lofexidine: (Major) Monitor ECG if lofexidine is coadministered with alfuzosin due to the potential for additive QT prolongation. Lofexidine prolongs the QT interval. In addition, there are postmarketing reports of torsade de pointes. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Alfuzosin is an alpha-blocker that does not commonly result in a drop in blood pressure, however, additive effects on blood pressure may also occur.
    Lomefloxacin: (Moderate) The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients with a known history of cardiac arrhythmias, QT prolongation, history of torsades de pointes, or patients who are taking quinolones.
    Long-acting beta-agonists: (Moderate) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Beta-agonists may be associated with adverse cardiovascular effects including QT interval prolongation, usually at higher doses and/or when associated with hypokalemia. Beta-agonists should be administered with caution to patients being treated with drugs known to prolong the QT interval because the action of beta-agonists on the cardiovascular system may be potentiated.
    Loperamide: (Major) At high doses, loperamide has been associated with serious cardiac toxicities, including syncope, ventricular tachycardia, QT prolongation, torsade de pointes (TdP), and cardiac arrest. Drugs with a possible risk for QT prolongation and TdP, like alfuzosin, should be used cautiously and with close monitoring with loperamide.
    Loperamide; Simethicone: (Major) At high doses, loperamide has been associated with serious cardiac toxicities, including syncope, ventricular tachycardia, QT prolongation, torsade de pointes (TdP), and cardiac arrest. Drugs with a possible risk for QT prolongation and TdP, like alfuzosin, should be used cautiously and with close monitoring with loperamide.
    Lopinavir; Ritonavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Lumacaftor; Ivacaftor: (Minor) Lumacaftor; ivacaftor may reduce the efficacy of alfuzosin by decreasing its systemic exposure. If used together, monitor the patient for appropriate clinical effects. Alfuzosin is a CYP3A4 substrate. Lumacaftor is a strong CYP3A inducer.
    Macimorelin: (Major) Avoid concurrent administration of macimorelin with drugs that prolong the QT interval, such as alfuzosin. Use of these drugs together may increase the risk of developing torsade de pointes-type ventricular tachycardia. Sufficient washout time of drugs that are known to prolong the QT interval prior to administration of macimorelin is recommended. Treatment with macimorelin has been associated with an increase in the corrected QT (QTc) interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Maprotiline: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and maprotiline should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Maprotiline has also been reported to prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Cases of long QT syndrome and TdP tachycardia have been described with maprotiline use, but rarely occur when the drug is used alone in normal prescribed doses and in the absence of other known risk factors for QT prolongation. Limited data are available regarding the safety of maprotiline in combination with other QT-prolonging drugs.
    Mefloquine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and mefloquine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. There is evidence that the use of halofantrine after mefloquine causes a significant lengthening of the QTc interval. Mefloquine alone has not been reported to cause QT prolongation. However, due to the lack of clinical data, mefloquine should be used with caution in patients receiving drugs that prolong the QT interval.
    Meperidine; Promethazine: (Moderate) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval; use these drugs with caution and with close clinical monitoring. Promethazine carries a possible risk of QT prolongation.
    Mesoridazine: (Severe) Alfuzosin has a slight effect to prolong the QT interval and should be used cautiously in combination with other drugs that may also prolong the QT interval including mesoridazine.
    Methadone: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and methadone should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Methadone is considered to be associated with an increased risk for QT prolongation and torsades de pointes (TdP), especially at higher doses (> 200 mg/day but averaging approximately 400 mg/day in adult patients). Laboratory studies, both in vivo and in vitro, have demonstrated that methadone inhibits cardiac potassium channels and prolongs the QT interval. Most cases involve patients being treated for pain with large, multiple daily doses of methadone, although cases have been reported in patients receiving doses commonly used for maintenance treatment of opioid addiction.
    Metoprolol: (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.
    Metronidazole: (Major) Potential QT prolongation has been reported in limited case reports with metronidazole. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with metronidazole include alfuzosin.
    Midostaurin: (Major) The concomitant use of midostaurin and alfuzosin may lead to additive QT interval prolongation. If these drugs are used together, consider obtaining electrocardiograms to monitor the QT interval. In clinical trials, QT prolongation was reported in patients who received midostaurin as single-agent therapy or in combination with cytarabine and daunorubicin. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Mifepristone: (Severe) Alfuzosin is contraindicated for use with mifepristone due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is a CYP3A4 substrate that has been associated with dose-dependent QT prolongation; mifepristone is a strong CYP3A4 inhibitor that has also been associated with dose-dependent prolongation of the QT interval. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Mirtazapine: (Major) There may be an increased risk for QT prolongation and torsade de pointes (TdP) during concurrent use of mirtazapine and alfuzosin. Coadminister with caution. Cases of QT prolongation, TdP, ventricular tachycardia, and sudden death have been reported during postmarketing use of mirtazapine. The majority of reports have occurred in the setting of mirtazapine overdose or in patients with other risk factors for QT prolongation, including concomitant use of other medications associated with QT prolongation. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Mitotane: (Moderate) Use caution if mitotane and alfuzosin are used concomitantly, and monitor for decreased efficacy of alfuzosin and a possible change in dosage requirements. Mitotane is a strong CYP3A4 inducer and alfuzosin is a CYP3A4 substrate; coadministration may result in decreased plasma concentrations of alfuzosin.
    Moxifloxacin: (Major) Concurrent use of alfuzosin and moxifloxacin should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Moxifloxacin has been associated with prolongation of the QT interval. Additionally, post-marketing surveillance has identified very rare cases of ventricular arrhythmias including TdP, usually in patients with severe underlying proarrhythmic conditions. The likelihood of QT prolongation may increase with increasing concentrations of moxifloxacin, therefore the recommended dose or infusion rate should not be exceeded. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Nadolol: (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.
    Nebivolol: (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.
    Nebivolol; Valsartan: (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.
    Nefazodone: (Severe) Alfuzosin is contraindicated for use with nefazodone due to the potential for serious/life-threatening reactions, including hypotension. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is primarily metabolized by CYP3A4; nefazodone is a strong inhibitor of this enzyme. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Nelfinavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Nicardipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Nifedipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Nilotinib: (Major) Avoid the concomitant use of nilotinib with other agents that prolong the QT interval, such as alfuzosin. Additionally, nilotinib is a moderate inhibitor of CYP3A4 and alfuzosin is a substrate of CYP3A4; administering these drugs together may result in increased alfuzosin levels. If the use of alfuzosin is necessary, hold nilotinib therapy. If these drugs are used together, consider an alfuzosin dose reduction and monitor patients for toxicity (e.g., QT interval prolongation).
    Nisoldipine: (Moderate) The concomitant administration of alpha-blockers with other antihypertensive agents can cause additive hypotensive effects. This interaction can be therapeutically advantageous, but dosages must be adjusted accordingly.
    Nitrates: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Nitroglycerin: (Moderate) The manufacturer of alfuzosin warns that concurrent use with nitrates has the potential to cause hypotension, orthostatic hypotension, or syncope. Caution is advisable when coadministering alfuzosin and a nitrate to patients with symptomatic hypotension or those who have had a previous hypotensive response to either agent.
    Norfloxacin: (Major) Due to an increased risk for QT prolongation and torsade de pointes (TdP), caution is advised when administering alfuzosin with norfloxacin. Alfuzosin has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Quinolones have also been associated with QT prolongation and TdP. For norfloxacin specifically, extremely rare cases of TdP were reported during post-marketing surveillance. These reports generally involved patients with concurrent medical conditions or concomitant medications that may have been contributory.
    Nortriptyline: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Octreotide: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and octreotide should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Arrhythmias, sinus bradycardia, and conduction disturbances have occurred during octreotide therapy warranting more cautious monitoring during octreotide administration in higher risk patients with cardiac disease. Since bradycardia is a risk factor for development of TdP, the potential occurrence of bradycardia during octreotide administration could theoretically increase the risk of TdP in patients receiving drugs that prolong the QT interval.
    Ofloxacin: (Major) Due to an increased risk for QT prolongation and torsade de pointes (TdP), caution is advised when administering alfuzosin with ofloxacin. Alfuzosin has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Some quinolones, including ofloxacin, have also been associated with QT prolongation. Additionally, post-marketing surveillance for ofloxacin has identified very rare cases of TdP.
    Olanzapine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and olanzapine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Limited data, including some case reports, suggest that olanzapine may be associated with a significant prolongation of the QTc interval. Therefore, caution is advised when administering olanzapine with drugs having an established causal association with QT prolongation and TdP.
    Ombitasvir; Paritaprevir; Ritonavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Ondansetron: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), ondansetron and alfuzosin should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Ondansetron has been associated with a dose-related increase in the QT interval and postmarketing reports of torsade de pointes (TdP). If ondansetron and alfuzosin must be coadministered, ECG monitoring is recommended.
    Oritavancin: (Moderate) Alfuzosin is metabolized by CYP3A4; oritavancin is a weak CYP3A4 inducer. Plasma concentrations and efficacy of alfuzosin may be reduced if these drugs are administered concurrently.
    Osimertinib: (Major) Avoid coadministration of alfuzosin with osimertinib if possible due to the risk of QT prolongation and torsade de pointes (TdP). If concomitant use is unavoidable, periodically monitor ECGs for QT prolongation and monitor electrolytes; an interruption of osimertinib therapy with dose reduction or discontinuation of therapy may be necessary if QT prolongation occurs. Concentration-dependent QTc prolongation occurred during clinical trials of osimertinib. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Oxaliplatin: (Major) Monitor ECGs and electrolytes in patients receiving oxaliplatin and alfuzosin concomitantly; correct electrolyte abnormalities prior to administration of oxaliplatin. QT prolongation and ventricular arrhythmias including fatal torsade de pointes have been reported with oxaliplatin use in postmarketing experience. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Oxymetazoline: (Major) Caution is advised when administering alfuzosin with oxymetazoline. Alfuzosin, an alpha adrenergic blocker, would likely antagonize the sympathomimetic effects of oxymetazoline, alpha adrenergic agonists; thereby reducing the effectiveness of oxymetazoline.
    Paliperidone: (Major) Paliperidone has been associated with QT prolongation; torsade de pointes (TdP) and ventricular fibrillation have been reported in the setting of overdose. According to the manufacturer, since paliperidone may prolong the QT interval, it should be avoided in combination with other agents also known to have this effect, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. If coadministration is considered necessary by the practitioner, and the patient has known risk factors for cardiac disease or arrhythmia, close monitoring is essential.
    Panobinostat: (Major) QT prolongation has been reported with panobinostat therapy in patients with multiple myeloma in a clinical trial; use of panobinostat with other agents that prolong the QT interval is not recommended. Obtain an electrocardiogram at baseline and periodically during treatment. Hold panobinostat if the QTcF increases to >= 480 milliseconds during therapy; permanently discontinue if QT prolongation does not resolve. Drugs with a possible risk for QT prolongation and torsade de pointes that should be used cautiously and with close monitoring with panobinostat include alfuzosin.
    Pasireotide: (Major) Cautious use and close monitoring of pasireotide and drugs that prolong the QT interval is needed, as coadministration may have additive effects on the prolongation of the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Pazopanib: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and pazopanib should be avoided. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Coadministration of pazopanib and other drugs that prolong the QT interval is not advised; pazopanib has been reported to prolong the QT interval. If pazopanib and the other drug must be continued, closely monitor the patient for QT interval prolongation.
    Penbutolol: (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.
    Pentamidine: (Major) Pentamidine has been associated with QT prolongation and torsade de pointes. Drugs with a possible risk for QT prolongation include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval; use caution in co-administration.
    Perphenazine: (Minor) Due to a possible risk for QT prolongation use these drugs together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Perphenazine, a phenothiazine, is associated with a possible risk for QT prolongation.
    Perphenazine; Amitriptyline: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). (Minor) Due to a possible risk for QT prolongation use these drugs together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Perphenazine, a phenothiazine, is associated with a possible risk for QT prolongation.
    Phenoxybenzamine: (Severe) The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects, therefore, alfuzosin should not be administered in combination with other alpha-blockers.
    Phentolamine: (Severe) The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects, therefore, alfuzosin should not be administered in combination with other alpha-blockers.
    Phenylephrine; Promethazine: (Moderate) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval; use these drugs with caution and with close clinical monitoring. Promethazine carries a possible risk of QT prolongation.
    Pimavanserin: (Major) Pimavanserin may cause QT prolongation and should generally be avoided in patients receiving other medications known to prolong the QT interval, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. Coadministration may increase the risk for QT prolongation.
    Pimozide: (Severe) Because of the potential for QT prolongation and torsade de pointes (TdP), use of alfuzosin with pimozide is contraindicated. Pimozide is associated with a well-established risk of QT prolongation and TdP. Based on electrophysiology studies, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Pindolol: (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.
    Posaconazole: (Severe) Alfuzosin is contraindicated for use with posaconazole due to the potential for serious/life-threatening reactions, including hypotension and QT prolongation. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is a CYP3A4 substrate that has been associated with dose-dependent QT prolongation; posaconazole is a strong CYP3A4 inhibitor that has been associated with prolongation of the QT interval as well as rare cases of torsade de pointes. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Prazosin: (Severe) The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects, therefore, alfuzosin should not be administered in combination with other alpha-blockers.
    Primaquine: (Major) Due to the potential for QT interval prolongation with primaquine, caution is advised with other drugs that prolong the QT interval. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with primaquine include alfuzosin.
    Procainamide: (Major) Alfuzosin should be used cautiously with procainamide. Procainamide is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Prochlorperazine: (Minor) Due to a possible risk for QT prolongation use these drugs together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Prochlorperazine is associated with a possible risk for QT prolongation.
    Promethazine: (Moderate) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval; use these drugs with caution and with close clinical monitoring. Promethazine carries a possible risk of QT prolongation.
    Propafenone: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering propafenone with alfuzosin. Propafenone is a Class IC antiarrhythmic which increases the QT interval, but largely due to prolongation of the QRS interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin also has a slight QT prolonging effect. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Propranolol: (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.
    Protease inhibitors: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Protriptyline: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Quetiapine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), coadministration of alfuzosin and quetiapine should be avoided. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Limited data, including some case reports, suggest that quetiapine may also be associated with a significant prolongation of the QTc interval in rare instances. Concurrent use may result in additive effects on the QT interval.
    Quinidine: (Major) Alfuzosin should be used cautiously with quinidine. Quinidine administration is associated with QT prolongation and torsades de pointes (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Quinine: (Major) Concurrent use of quinine and alfuzosin should be avoided due to an increased risk for QT prolongation and torsade de pointes (TdP). Quinine has been associated with prolongation of the QT interval and rare cases of TdP. Based on electrophysiology studies performed by the manufacturer, alfuzosin also has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. In addition, concentrations of alfuzosin may be increased with concomitant use of quinine. Alfuzosin is a CYP3A4 substrate and quinine is a CYP3A4 inhibitor.
    Ranolazine: (Major) Ranolazine is associated with dose- and plasma concentration-related increases in the QTc interval. The mean increase in QTc is about 6 milliseconds, measured at the tmax of the maximum dosage (1000 mg PO twice daily). However, in 5% of the population studied, increases in the QTc of at least 15 milliseconds have been reported. Although there are no studies examining the effects of ranolazine in patients receiving other QT prolonging drugs, coadministration of such drugs may result in additive QT prolongation. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously with ranolazine include alfuzosin. In addition, alfuzosin is primarily metabolized by CYP3A4 hepatic enzymes; inhibitors of CYP3A4, such as ranolazine, may inhibit alfuzosin metabolism and increase systemic exposure to alfuzosin.
    Ribociclib: (Severe) Alfuzosin is contraindicated for use with ribociclib due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Ribociclib is a strong CYP3A4 inhibitor that has also been shown to prolong the QT interval in a concentration-dependent manner. Concomitant use may increase the risk for QT prolongation.
    Ribociclib; Letrozole: (Severe) Alfuzosin is contraindicated for use with ribociclib due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Alfuzosin is a CYP3A4 substrate that may prolong the QT interval in a dose-dependent manner. Ribociclib is a strong CYP3A4 inhibitor that has also been shown to prolong the QT interval in a concentration-dependent manner. Concomitant use may increase the risk for QT prolongation.
    Rilpivirine: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering rilpivirine with alfuzosin. Supratherapeutic doses of rilpivirine (75 to 300 mg/day) have caused QT prolongation. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Risperidone: (Major) Risperidone has been associated with a possible risk for QT prolongation and/or torsade de pointes; however, data are currently lacking to establish causality in association with torsades de pointes (TdP). Reports of QT prolongation and torsades de pointes during risperidone therapy are noted by the manufacturer, primarily in the overdosage setting. Since risperidone may prolong the QT interval, it should be used cautiously with other agents also known to have this effect, taking into account the patient's underlying disease state(s) and additional potential risk factors. If coadministration is chosen, and the patient has known risk factors for cardiac disease or arrhythmia, then the patient should be closely monitored clinically. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously with risperidone include alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Ritonavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Romidepsin: (Major) Romidepsin has been reported to prolong the QT interval. If romidepsin must be coadministered with another drug that prolongs the QT interval, such as alfuzosin, appropriate cardiovascular monitoring precautions should be considered, such as the monitoring of electrolytes and ECGs at baseline and periodically during treatment. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Saquinavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Sertraline: (Major) There have been postmarketing reports of QT prolongation and torsade de pointes (TdP) during treatment with sertraline and the manufacturer of sertraline recommends avoiding concurrent use with drugs known to prolong the QTc interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Sevoflurane: (Major) Halogenated anesthetics should be used cautiously and with close monitoring with alfuzosin. Halogenated anesthetics can prolong the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Short-acting beta-agonists: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Beta-agonists may be associated with adverse cardiovascular effects including QT interval prolongation, usually at higher doses and/or when associated with hypokalemia. Beta-agonists should be administered with caution to patients being treated with drugs known to prolong the QT interval because the action of beta-agonists on the cardiovascular system may be potentiated.
    Sildenafil: (Moderate) Thereis is a risk of enhanced hypotensive effects in individual patients when alfuzosin is co-administered with phosphodiesterase (PDE5) inhibitors such as sildenafil. Sildenafil doses greater than 25 mg should not be taken within 4 hours of taking an alpha-blocker. Patients should be stabilized on their alpha blocker therapy prior to starting sildenafil, or if already receiving an optimum dose of sildenafil, the alpha blocker therapy should be started at the lowest possible dose. Concurrent use of PDE5 inhibitors and alpha-blockers may lead to symptomatic hypotension in some patients. There have been infrequent reports of patients who experienced symptomatic postural hypotension. These reports included dizziness and light-headedness, but not syncope. Despite the potential for interaction, with regimen modifications, patients can take these drugs together.
    Silodosin: (Severe) The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects, therefore, alfuzosin should not be administered in combination with other alpha-blockers.
    Simeprevir: (Moderate) Simeprevir, a mild intestinal CYP3A4 inhibitor, may increase the side effects of alfuzosin, which is a CYP3A4 substrate. Monitor patients for adverse effects of alfuzosin, such as dizziness, hypotension, and syncope.
    Solifenacin: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and solifenacin should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Solifenacin has been associated with dose-dependent prolongation of the QT interval. TdP has been reported with postmarketing use, although causality was not determined. This should be taken into consideration when prescribing solifenacin to patients taking other drugs that are associated with QT prolongation.
    Sorafenib: (Major) Monitor ECGs for QT prolongation and monitor electrolytes if coadministration of sorafenib with alfuzosin is necessary; correct any electrolyte abnormalities. An interruption or discontinuation of sorafenib therapy may be necessary if QT prolongation occurs. Sorafenib has been associated with QT prolongation. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Sotalol: (Major) Use caution during concurrent administration. Sotalol administration is associated with QT prolongation and torsades de pointes (TdP). Proarrhythmic events should be anticipated after initiation of therapy and after each upward dosage adjustment. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Sparfloxacin: (Severe) Alfuzosin has a slight effect to prolong the QT interval, and should be used cautiously in combination with other medications known to prolong the QT interval, such as sparfloxacin.
    Sunitinib: (Major) Monitor patients for QT prolongation if coadministration of alfuzosin with sunitinib is necessary. Sunitinib can cause dose-dependent QT prolongation, which may increase the risk for ventricular arrhythmias, including torsades de points (TdP). Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Tacrolimus: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and tacrolimus should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Tacrolimus causes QT prolongation. Reducing the tacrolimus dose, close monitoring of tacrolimus whole blood concentrations, and monitoring for QT prolongation is recommended when coadministrating tacrolimus with other substrates and/or inhibitors of CYP3A4 that also have the potential to prolong the QT interval such as alfuzosin.
    Tadalafil: (Moderate) Concurrent use of phosphodiesterase (PDE5) inhibitors, such as tadalafil, with an alpha blocker, such as alfuzosin, may lead to symptomatic hypotension in some patients. Patients should be stabilized on alpha blocker therapy prior to starting tadalafil, or if receiving optimum dose of tadalafil, the alpha blocker therapy should be started at the lowest possible dose.
    Tamoxifen: (Major) Caution is advised with the concomitant use of tamoxifen with alfuzosin due to an increased risk of QT prolongation. Tamoxifen has been reported to prolong the QT interval, usually in overdose or when used in high doses. Rare case reports of QT prolongation have also been described when tamoxifen is used at lower doses. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Concomitant use may increase the risk of QT prolongation.
    Telaprevir: (Severe) The concurrent use of alfuzosin and telaprevir is contraindicated due to the potential for serious/life-threatening reactions. Telaprevir is an inhibitor of CYP3A4, which is responsible for alfuzosin metabolism. Coadministration may result in large increases in alfuzosin serum concentrations, which could cause adverse events such as hypotension and cardiac arrhythmias.
    Telavancin: (Major) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering telavancin with alfuzosin. Telavancin has been associated with QT prolongation. Alfuzosin also has a slight QT prolonging effect, based on electrophysiology studies performed by the manufacturer. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Telithromycin: (Severe) Alfuzosin is contraindicated for use with telithromycin due to the potential for serious/life-threatening reactions, including hypotension. Additive effects on the QT interval may also occur. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is a CYP3A4 substrate that has been associated with dose-dependent QT prolongation; telithromycin is a strong CYP3A4 inhibitor that is associated with QT prolongation and torsade de pointes (TdP). Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Telotristat Ethyl: (Moderate) Use caution if coadministration of telotristat ethyl and alfuzosin is necessary, as the systemic exposure of alfuzosin may be decreased resulting in reduced efficacy. If these drugs are used together, monitor patients for suboptimal efficacy of alfuzosin; consider increasing the dose of alfuzosin if necessary. Alfuzosin is a CYP3A4 substrate. The mean Cmax and AUC of another sensitive CYP3A4 substrate was decreased by 25% and 48%, respectively, when coadministered with telotristat ethyl; the mechanism of this interaction appears to be that telotristat ethyl increases the glucuronidation of the CYP3A4 substrate.
    Terazosin: (Severe) The pharmacokinetic and pharmacodynamic interactions between alfuzosin and other alpha-blockers (used for high blood pressure or for benign prostatic hyperplasia) have not been determined. However, interactions or side effects (dizziness, hypotension, syncope, etc.) may be expected from the duplication of pharmacologic effects, therefore, alfuzosin should not be administered in combination with other alpha-blockers.
    Tetrabenazine: (Major) Tetrabenazine causes a small increase in the corrected QT interval (QTc). The manufacturer recommends avoiding concurrent use of tetrabenazine with other drugs known to prolong QTc, such as alfuzosin. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg.
    Thioridazine: (Severe) Thioridazine is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Thioridazine is considered contraindicated for use along with agents that, when combined with a phenothiazine, may prolong the QT interval and increase the risk of TdP, and/or cause orthostatic hypotension. Because of the potential for TdP, use of alfuzosin with thioridazine is contraindicated.
    Timolol: (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.
    Tipranavir: (Severe) Coadministration of alfuzosin and protease inhibitors is contraindicated due to increased alfuzosin exposure. Protease inhibitors are strong CYP3A4 inhibitors. Alfuzosin is a CYP3A4 substrate. When coadministered with another strong CYP3A4 inhibitor, the AUC of alfuzosin was increased by 2.5-fold to 3.2-fold.
    Tolterodine: (Moderate) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and tolterodine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tolterodine has been associated with dose-dependent prolongation of the QT interval, especially in poor CYP2D6 metabolizers. This should be taken into consideration when prescribing tolterodine to patients taking other drugs that are associated with QT prolongation.
    Toremifene: (Major) Avoid coadministration of alfuzosin with toremifene if possible due to the risk of additive QT prolongation. If concomitant use is unavoidable, closely monitor ECGs for QT prolongation and monitor electrolytes; correct hypokalemia or hypomagnesemia prior to administration of toremifene. Toremifene has been shown to prolong the QTc interval in a dose- and concentration-related manner. Based on electrophysiology studies performed by the manufacturer, alfuzosin may also prolong the QT interval in a dose-dependent manner.
    Trandolapril; Verapamil: (Moderate) Monitor blood pressure if coadministration of alfuzosin and verapamil is necessary. This combination has the potential to cause hypotension in some patients. Coadministration may also result in increased alfuzosin serum concentrations. Alfuzosin is primarily metabolized by the CYP3A4 hepatic enzyme. In addition to potential for additive hypotension with alfuzosin, verapamil may also inhibit the metabolism of alfuzosin.
    Trazodone: (Major) Trazodone should be avoided in combination with alfuzosin. Trazodone can prolong the QT/QTc interval at therapeutic doses. In addition, there are post-marketing reports of torsade de pointes (TdP). Therefore, the manufacturer recommends avoiding trazodone in patients receiving other drugs that increase the QT interval. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval.
    Tricyclic antidepressants: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Trifluoperazine: (Minor) Due to a possible risk for QT prolongation use these drugs together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Trifluoperazine, a phenothiazine, is associated with a possible risk for QT prolongation.
    Trimipramine: (Minor) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval. Tricyclic antidepressants should be used cautiously and with close monitoring with alfuzosin. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
    Triptorelin: (Major) Androgen deprivation therapy (e.g., triptorelin) prolongs the QT interval; the risk may be increased with the concurrent use of drugs that may prolong the QT interval. Drugs with a possible risk for QT prolongation and TdP that should be used cautiously and with close monitoring with triptorelin include alfuzosin.
    Vandetanib: (Major) Avoid coadministration of vandetanib with alfuzosin due to an increased risk of QT prolongation and torsade de pointes (TdP). If concomitant use is unavoidable, monitor ECGs for QT prolongation and monitor electrolytes; correct hypocalcemia, hypomagnesemia, and/or hypomagnesemia prior to vandetanib administration. An interruption of vandetanib therapy or dose reduction may be necessary for QT prolongation. Vandetanib can prolong the QT interval in a concentration-dependent manner; TdP and sudden death have been reported in patients receiving vandetanib. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.
    Vardenafil: (Major) There is a risk of enhanced hypotensive effects in individual patients when alfuzosin is co-administered with vardenafil. Concurrent use of PDE5 inhibitors and alpha-blockers may lead to symptomatic hypotension in some patients. Patients should be stabilized on their alpha blocker therapy prior to starting vardenafil, or, if already receiving an optimum dose of vardenafil, the alpha blocker therapy should be started at the lowest possible dose. Vardenafil is associated with QT prolongation. Both therapeutic and supratherapeutic doses of vardenafil produce an increase in QTc interval. Alfuzosin has also been reported to cause QT prolongation; use together may increase this risk.
    Vemurafenib: (Major) Vemurafenib has been associated with QT prolongation. If vemurafenib and another drug, such as alfuzosin, that is associated with a possible risk for QT prolongation and torsade de pointes (TdP) must be coadministered, ECG monitoring is recommended; closely monitor the patient for QT interval prolongation. In addition to avoiding concurrent drug interactions, the potential for TdP can be reduced by avoiding the use of QT prolonging drugs in patients at substantial risk for TdP. Examples of general risk factors for TdP include congenital long QT syndrome, female sex, elderly patients, significant bradycardia, hypokalemia, hypomagnesemia, and underlying cardiac disease (e.g., arrhythmias, cardiomyopathy, acute myocardial ischemia). Also, alfuzosin is a CYP3A4 substrate, while vemurafenib is a CYP3A4 substrate and inducer; therefore, concentrations of alfuzosin may be decreased.
    Venlafaxine: (Major) Due to a possible risk for QT prolongation and torsade de pointes (TdP), alfuzosin and venlafaxine should be used together cautiously. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner. Venlafaxine administration is associated with a possible risk of QT prolongation; TdP has reported with postmarketing use. Coadministration may increase the risk of QT prolongation.
    Verapamil: (Moderate) Monitor blood pressure if coadministration of alfuzosin and verapamil is necessary. This combination has the potential to cause hypotension in some patients. Coadministration may also result in increased alfuzosin serum concentrations. Alfuzosin is primarily metabolized by the CYP3A4 hepatic enzyme. In addition to potential for additive hypotension with alfuzosin, verapamil may also inhibit the metabolism of alfuzosin.
    Voriconazole: (Severe) Alfuzosin is contraindicated for use with voriconazole due to the potential for serious/life-threatening reactions, including hypotension and QT prolongation. Coadministration is expected to reduce the metabolism and increase systemic exposure to alfuzosin. Alfuzosin is a CYP3A4 substrate that has been associated with dose-dependent QT prolongation; voriconazole is a strong CYP3A4 inhibitor that has been associated with QT prolongation and rare cases of torsade de pointes. Coadministration of another strong CYP3A4 inhibitor increased the alfuzosin AUC by 2.5-fold to 3.2-fold.
    Vorinostat: (Major) Based on electrophysiology studies performed by the manufacturer, alfuzosin has a slight effect to prolong the QT interval. The QT prolongation appeared less with alfuzosin 10 mg than with 40 mg. The manufacturer warns that the QT effect of alfuzosin should be considered prior to administering the drug to patients taking other medications known to prolong the QT interval, such as vorinostat. Vorinostat therapy is associated with a risk of QT prolongation and should be used with caution if given with other agents that may prolong the QT interval including alfuzosin.
    Ziprasidone: (Major) Concomitant use of ziprasidone and alfuzosin should be avoided due to the potential for additive QT prolongation. Clinical trial data indicate that ziprasidone causes QT prolongation; there are postmarketing reports of torsade de pointes (TdP) in patients with multiple confounding factors. Based on electrophysiology studies performed by the manufacturer, alfuzosin may prolong the QT interval in a dose-dependent manner.

    PREGNANCY AND LACTATION

    Pregnancy

    Alfuzosin is not indicated for use in females; therefore, no adequate well-controlled studies in pregnant women have been done to assess the safety of alfuzosin use during pregnancy. Alfuzosin was not teratogenic, embryotoxic or fetotoxic in rats at plasma exposure levels (based on AUC of unbound drug) up to 1,200-times the maximum recommended human dose (MRHD) of 10 mg/day. In rabbits administered up to 3-times the MRHD (based on body surface area) no embryofetal toxicity or teratogenicity was observed. Gestation was slightly prolonged in rats at exposure levels approximately 12-times the MRHD, but difficulties with parturition were not observed.

    There is no known use of alfuzosin in breast-feeding mothers; it is not known whether alfuzosin distributes into breast milk.

    MECHANISM OF ACTION

    Alfuzosin is a selective antagonist at alpha-1 receptors. Blockade of these receptors by alfuzosin can cause smooth muscles in the bladder neck and prostate to relax, thereby reducing pressure on the urethra and improving urine flow rate. This results in a reduction in the symptoms of benign prostatic hypertrophy (BPH) and improves urinary flow. Alpha-1 receptors are involved in contraction of smooth muscle and are abundant in the prostate, prostatic capsule, prostatic urethra, bladder base, and bladder neck. Three subtypes of alpha-1 receptors have been identified: Alpha-1a, alpha-1b, and alpha-1d. Alpha-1a receptors mediate human prostatic smooth muscle contraction whereas alpha-1b and alpha-1d receptors are involved in vascular smooth muscle contraction. Both alpha-1a and alpha-1b receptors exist in the prostate, however, approximately 70% of the alpha receptors in the human prostate are of the alpha-1a subtype. Similar to tamsulosin, alfuzosin appears to be more specific for alpha-1a receptors than other alpha-1 blockers.

    PHARMACOKINETICS

    Alfuzosin is administered orally as a sustained-release dosage form. Steady-state plasma concentrations are attained after a second dose and are 1.2- to 1.6-fold higher than those following single doses. In the systemic circulation, it is approximately 82% to 90% protein bound. Penetration into the CNS is low. Alfuzosin is extensively metabolized by the liver to inactive metabolites; the metabolic pathways involved are oxidation, O-demethylation, and N-dealkylation. CYP3A4 is the principal hepatic enzyme involved in metabolism. About 11% of the parent compound is excreted unchanged in the urine. The metabolites are primarily excreted in the feces. Radiolabeled studies show 69% of an administered dose is excreted in the feces and 24% in the urine. The terminal elimination half-life is about 10 hours. Multiple dosing does not affect the elimination half-life.
     
    Affected cytochrome P450 (CYP450) isoenzymes and drug transporters: CYP3A4
    CYP3A4 is the principal enzyme involved in alfuzosin metabolism. Potent inhibitors of CYP3A4 are contraindicated for use with alfuzosin, as alfuzosin blood concentrations are greatly increased (approximately 2 to 3-fold) in the presence of such inhibitors. Alfuzosin does not inhibit CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6 or CYP3A4; it does not induce CYP1A, CYP2A6, or CYP3A4.

    Oral Route

    Alfuzosin extended-release tablets are absorbed rapidly with an absolute bioavailability of 49% under fed conditions once released. Under fasting conditions, the extent of absorption is 50% lower. The extended-release tablets must be taken with food and not on an empty stomach. The time to peak concentration (Tmax) is 8 hours.