PDR MEMBER LOGIN:
  • PDR Search

    Required field
  • Advertisement
  • CLASSES

    Decongestant and Expectorant Combinations

    DEA CLASS

    Rx, OTC

    DESCRIPTION

    Oral expectorant and sympathomimetic decongestant combination
    Primarily used for the temporary relief of congestion associated with the common cold or other upper respiratory conditions
    Used in adults and pediatric patients 6 years and older

    COMMON BRAND NAMES

    Aldex GS, Ambi, Ambifed-G, Aquatab D, Congestac, D Feda II, Decongest II, Deconsal II, Defen LA, Desal II, Durasal II, Dynex, Entex T, ExeFen, ExeFen-IR, Guaifenex PSE-60, Guiatex II SR, Iosal II, Maxifed, Maxifed-G, Medent-LDI, Mucinex D, Poly-Vent IR, Respaire-30, Robitussin Severe Congestion, Sinutab, Sudafed Non-Drying Sinus, SudaTex-G, Zephrex

    HOW SUPPLIED

    Aldex GS/Ambi/Ambifed/Ambifed-G/Congestac/Dynex/Entex T/ExeFen/ExeFen-IR/Guaifenesin, Pseudoephedrine/Guaifenesin, Pseudoephedrine Hydrochloride/Maxifed/Maxifed-G/Medent-LDI/Poly-Vent IR/SudaTex-G/Zephrex Oral Tab: 1200-90mg, 190-30mg, 375-60mg, 380-60mg, 400-20mg, 400-30mg, 400-40mg, 400-60mg, 780-80mg
    Ambi/Guaifenesin, Pseudoephedrine/Guaifenesin, Pseudoephedrine Hydrochloride/Maxifed-G/Mucinex D/SudaTex-G Oral Tab ER: 1200-120mg, 580-60mg, 600-60mg
    Respaire-30 Oral Cap: 150-30mg

    DOSAGE & INDICATIONS

    For the treatment of cough and nasal congestion, including relief of eustachian tube congestion, associated with the common cold, sinusitis, or other upper respiratory conditions.
    Oral dosage (biphasic/extended-release tablets with guaifenesin 580 or 600 mg and pseudoephedrine 60 mg; e.g., Mucinex D, SudaTex-G)
    Adults, Adolescents, and Children 12 years and older

    2 tablets PO every 12 hours as needed. Max: 4 tablets/day PO.

    Oral dosage (biphasic-release tablets with guaifenesin 1200 mg and pseudoephedrine 120 mg, e.g., Mucinex D Maximum Strength)
    Adults, Adolescents, and Children 12 years and older

    1 tablet PO every 12 hours as needed. Max: 2 tablets/day PO.

    Oral dosage (immediate-release tablets with guaifenesin 400 mg and pseudoephedrine 20 mg or 30 mg; e.g., Ambifed-G or Ambifed)
    Adults

    1 tablet PO every 4 to 6 hours as needed. Max: 6 tablets/24 hours PO.

    Adolescents and Children 12 years and older

    1 tablet PO every 4 to 6 hours as needed. Max: 6 tablets/24 hours PO.

    Children 6 to 11 years

    One-half tablet PO every 4 to 6 hours as needed. Max: 3 tablets/24 hours PO.

    Oral dosage (tablets with guaifenesin 780 mg and pseudoephedrine 80 mg; e.g., ExeFen)
    Adults, Adolescents, and Children 12 years and older

    1 tablet PO every 12 hours as needed. Max: 2 tablets/24 hours.

    Oral dosage (immediate-release tablets containing guaifenesin 400 mg with pseudoephedrine 40 mg; e.g., AMBI, Maxifed-G 40/400)
    Adults

    1 tablet PO every 4 to 6 hours as needed. Do not exceed 6 tablets/24 hours.

    Children and Adolescents 12 years and older

    1 tablet PO every 4 to 6 hours as needed. Do not exceed 6 tablets/24 hours.

    Children 6 to 11 years

    One-half tablet PO every 4 to 6 hours as needed. Do not exceed 3 tablets/24 hours.

    Oral dosage (tablets containing guaifenesin 380 mg or 400 mg with pseudoephedrine 60 mg; e.g., Congestac, Maxifed, Poly-Vent IR)
    Adults

    1 tablet PO every 6 hours as needed. Do not exceed 4 tablets/24 hours.

    Children and Adolescents 12 years and older

    1 tablet PO every 6 hours as needed. Do not exceed 4 tablets/24 hours.

    Children 6 to 11 years

    One-half tablet PO every 6 hours as needed. Do not exceed 2 tablets/24 hours.

    Oral dosage (capsules with guaifenesin 200 mg and pseudoephedrine 30 mg; e.g., Wal-Tussin Cold Severe Congestion Softgel)
    Adults, Adolescents, and Children 12 years and older

    Dosage was 2 capsules PO every 4 hours as needed. Max: 8 capsules/day.

    Children 6 to 11 years

    Dosage was 1 capsule PO every 4 hours as needed. Max: 4 capsules/day.

    MAXIMUM DOSAGE

    NOTE: Do not exceed recommended dosage limits for the specific product prescribed; the following are general guidelines:

    Adults

    Guaifenesin 2400 mg/day PO; pseudoephedrine 240 mg/day PO.

    Geriatric

    Guaifenesin 2400 mg/day PO; pseudoephedrine 240 mg/day PO.

    Adolescents

    Guaifenesin 2400 mg/day PO; pseudoephedrine 240 mg/day PO.

    Children

    12 years: Guaifenesin 2400 mg/day PO; pseudoephedrine 240 mg/day PO.
    6 to 11 years: Guaifenesin 1200 mg/day PO; pseudoephedrine 120 mg/day PO.
    Less than 5 years: Safety and efficacy have not been established.

    Infants

    Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.

    Renal Impairment

    CrCl less than 30 mL/minute: Reduce the initial pseudoephedrine dosage by 50% (Adult Max: 120 mg/day PO), to avoid potential drug accumulation and toxicity.

    ADMINISTRATION

    Oral Administration

    Guaifenesin; pseudoephedrine products are administered orally.

    Oral Solid Formulations

    Regular-release tablets: Administer last dose 2 hours before bedtime to minimize insomnia due to pseudoephedrine.
    Extended-release tablets: Swallow whole; do not crush or chew. Scored tablets may be divided in half.
    Extended-release capsules: Swallow whole; do not crush or chew. For patients with difficulty swallowing, extended-release capsules may be opened and mixed with jam or jelly and swallowed without chewing.

    Oral Liquid Formulations

    Oral solution: Administer using a calibrated spoon, cup, or syringe to ensure accurate dosing. Note that some guaifenesin; pseudoephedrine syrups contain alcohol.

    STORAGE

    Aldex GS:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Altarussin PE:
    - Store at room temperature (between 59 to 86 degrees F)
    Altex-PSE:
    - Storage information not listed
    Ambi:
    - Store at room temperature (between 59 to 86 degrees F)
    Ambifed :
    - Protect from light
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Ambifed-G:
    - Protect from light
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Ami-Tex PSE:
    - Storage information not listed
    Aquatab D:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Coldmist JR:
    - Avoid exposure to heat
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Coldmist LA :
    - Store at room temperature (between 59 to 86 degrees F)
    Congestac:
    - Store at room temperature (between 59 to 86 degrees F)
    D Feda II:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Decongest II :
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Deconsal II:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Defen LA:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Desal II :
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Drituss GP:
    - Avoid exposure to heat
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Durasal II :
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Duratuss:
    - Storage information not listed
    Duratuss GP:
    - Avoid exposure to heat
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Dynex:
    - Store at room temperature (between 59 to 86 degrees F)
    Entex PSE:
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F
    Entex T:
    - Store between 68 to 77 degrees F
    ExeFen:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    ExeFen-IR:
    - Store at room temperature (between 59 to 86 degrees F)
    Guaidrine GP:
    - Avoid exposure to heat
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Guaidrine PSE:
    - Storage information not listed
    Guaifen PSE:
    - Storage information not listed
    Guaifenex GP:
    - Avoid exposure to heat
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Guaifenex PSE-120:
    - Storage information not listed
    Guaifenex PSE-60:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Guaifenex PSE-80:
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F
    Guaifenex PSE-85:
    - Store at room temperature (between 59 to 86 degrees F)
    Guaimax D :
    - Storage information not listed
    Guaipax PSE:
    - Storage information not listed
    Guai-Vent-PSE:
    - Storage information not listed
    Guiatex II SR :
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Iosal II :
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Iotex PSE:
    - Storage information not listed
    Levall G:
    - Store at room temperature (between 59 to 86 degrees F)
    Maxifed:
    - Store at room temperature (between 59 to 86 degrees F)
    Maxifed-G:
    - Store at room temperature (between 59 to 86 degrees F)
    Medent-LDI:
    - Store at room temperature (between 59 to 86 degrees F)
    Miraphen PSE :
    - Storage information not listed
    Mucinex D:
    - Store between 68 to 77 degrees F
    Nasatab LA:
    - Store at room temperature (between 59 to 86 degrees F)
    Nomuc-PE :
    - Store at controlled room temperature (between 68 and 77 degrees F)
    PanMist JR:
    - Avoid exposure to heat
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    PanMist LA:
    - Store at room temperature (between 59 to 86 degrees F)
    PanMist S:
    - Store at room temperature (between 59 to 86 degrees F)
    Poly-Vent IR:
    - Store at room temperature (between 59 to 86 degrees F)
    Profen Forte :
    - Store at room temperature (between 59 to 86 degrees F)
    Profen II:
    - Store at room temperature (between 59 to 86 degrees F)
    Pseudatex:
    - Protect from light
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F
    Pseudo GG TR :
    - Avoid exposure to heat
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Pseudovent:
    - Store at room temperature (between 59 to 86 degrees F)
    Pseudovent-400:
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F
    Pseudovent-PED:
    - Store at room temperature (between 59 to 86 degrees F)
    Q-Tussin PE:
    - Store at room temperature (between 59 to 86 degrees F)
    Respaire SR:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Respaire-30 :
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F
    Robitussin PE:
    - Store at room temperature (between 59 to 86 degrees F)
    Robitussin Severe Congestion:
    - Protect from light
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Ru-Tuss DE:
    - Storage information not listed
    Ru-Tuss Jr.:
    - Protect from light
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Sinutab:
    - Protect from light
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Stamoist E:
    - Store at room temperature (between 59 to 86 degrees F)
    Sudafed Non-Drying Sinus:
    - Protect from light
    - Protect from moisture
    - Store at room temperature (between 59 to 86 degrees F)
    Sudal SR:
    - Store at room temperature (between 59 to 86 degrees F)
    SudaTex :
    - Store at room temperature (between 59 to 86 degrees F)
    SudaTex-G :
    - Store at room temperature (between 59 to 86 degrees F)
    Touro LA:
    - Store at room temperature (between 59 to 86 degrees F)
    Touro LA-LD:
    - Store at room temperature (between 59 to 86 degrees F)
    Triaminic Chest and Nasal Congestion:
    - Store at room temperature (between 59 to 86 degrees F)
    Tusnel Pediatric:
    - Protect from light
    - Store at room temperature (between 59 to 86 degrees F)
    WE Mist II LA:
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F
    Zephrex:
    - Store at room temperature (between 59 to 86 degrees F)

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    Guaifenesin; pseudoephedrine is contraindicated in individuals with known hypersensitivity to sympathomimetics.
     
    Guaifenesin may alter some laboratory tests. It may increase renal clearance for urate and lower serum uric acid levels. Guaifenesin may produce an increase in urinary 5-hydroxyindoleacetic acid and may therefore interfere with the interpretation of this diagnostic test for carcinoid syndrome. Guaifenesin may also falsely elevate the VMA test for catechols. Products containing guaifenesin should be discontinued at least 48 hours prior to the collection of urine specimens for such laboratory tests.

    MAOI therapy

    Pseudoephedrine-containing products should not be combined with MAOI therapy or within 2 weeks of such therapy.

    Asthma, bronchitis, emphysema, tobacco smoking

    Guaifenesin-containing products should not be used for persistent or chronic cough such as occurs with tobacco smoking, asthma, emphysema, or chronic bronchitis or any other condition where cough is associated with excessive secretions, unless under the supervision of a health care professional.

    Fever

    A fever may be indicative of a serious condition. Guaifenesin-containing products should be used in patients with a high temperature only under the direction of a physician.

    Acute myocardial infarction, angina, cardiac arrhythmias, cardiac disease, cardiomyopathy, coronary artery disease, heart failure, hypertension, myocardial infarction, tachycardia

    Well-controlled hypertensive adult patients receiving pseudoephedrine at recommended doses (240 mg/day PO) generally do not appear at risk for significant elevations in blood pressure; however, small increases in blood pressure and heart rate may occur. Although considered safe in the general population of controlled hypertensives, increased blood pressure (especially systolic hypertension) has been reported in individual patients receiving pseudoephedrine. Since pseudoephedrine is a vasoconstrictor and may increase heart rate via sympathomimetic effects, it should be avoided in patients with uncontrolled or severe hypertension or severe coronary artery disease (including history of myocardial infarction, acute myocardial infarction, or angina). Considerable caution should be used in patients with controlled or mild hypertension, heart failure, cardiomyopathy, acute cardiac arrhythmias (tachycardia), or other cardiac disease. Guaifenesin should not be used for a cough that is specifically associated with heart failure or ACE inhibitor therapy.

    Closed-angle glaucoma, diabetes mellitus, hyperthyroidism, peripheral vascular disease, prostatic hypertrophy, urinary retention

    Pseudoephedrine is also contraindicated for use in patients with closed-angle glaucoma and urinary retention due to prostatic hypertrophy. It is relatively contraindicated in patients with hyperthyroidism, diabetes mellitus, or peripheral vascular disease because sympathomimetics can exacerbate these conditions.

    Renal failure, renal impairment

    Pseudoephedrine is primarily eliminated by renal excretion; pseudoephedrine should be used with caution in patients with renal impairment and a dosage reduction is warranted. Due to decreased elimination and potential pseudoephedrine drug accumulation, patients with renal failure may at increased risk for drug-related toxicity.

    Children, infants

    Use of fixed-dose guaifenesin; pseudoephedrine combination products in infants and children less than 2 years of age is not recommended; many products containing guaifenesin; pseudoephedrine are not for use in children less than 6 years of age. Read product labels carefully. The adverse effects of sympathomimetics such as pseudoephedrine can be severe, especially in infants and toddlers; CNS stimulation, increased blood pressure, and tachycardia may occur. In January 2007, the CDC warned caregivers and healthcare providers of the risk for serious injury or fatal overdose from the administration of cough and cold products to children and infants less than 2 years of age; some cases were due to inadvertent inappropriate use. The report estimated that 1,519 children less than 2 years of age were treated in emergency departments during 2004 to 2005 for adverse events related to cough and cold medications. In October 2007, the FDA Nonprescription Drug Advisory Committee and the Pediatric Advisory Committee recommended that nonprescription cough and cold products containing pseudoephedrine, dextromethorphan, chlorpheniramine, diphenhydramine, brompheniramine, phenylephrine, clemastine, or guaifenesin not be used in children less than 6 years of age. In January 2008, the FDA issued a Public Health Advisory recommending that OTC cough and cold products not be used in infants and children less than 2 years. If cough and cold products are used in children, labels should be read carefully, caution should be used when administering multiple products, and only measuring devices specifically designed for use with medications should be used. Clinicians should thoroughly assess each patient's use of similar products, both prescription and nonprescription, to avoid duplication of therapy and the potential for inadvertent overdose.

    Pregnancy

    Both guaifenesin and pseudoephedrine are classified as pregnancy category C drugs. Adequate or well-controlled pregnancy studies have not been done in humans. Some sympathomimetic amines are associated with minor malformations in some animal species; however, human teratogenesis has not been suspected based on limited epidemiologic evidence. Use of guaifenesin; pseudoephedrine during pregnancy should be avoided unless the potential benefits outweigh the unknown potential risks to the fetus. When administered to pregnant women, product formulations that also contain ethanol or other drugs should not be used.

    Breast-feeding

    It is not known whether guaifenesin is excreted into human breast milk. Pseudoephedrine is excreted into breast milk, with peak milk concentrations occur 1—1.5 hours after a maternal oral dosage. Peak milk concentrations of pseudoephedrine usually exceed those of maternal plasma. The total amount of pseudoephedrine (measured by AUC) in milk is 2—3 times that of plasma. However, only 0.5% of a maternal dose would probably be ingested by an infant during breast-feeding within any 24 hours. The American Academy of Pediatrics has considered the use of pseudoephedrine to be compatible with lactation. Lactating women may want to avoid breast-feeding during times of peak concentrations (i.e., within 1—2 hours after a dose) when possible. Sympathomimetic adverse effects (irritability, excessive crying, and altered sleeping patterns) have been reported in a breast-fed infant following maternal administration of pseudoephedrine; symptoms resolved within 12 hours of drug discontinuation. Guaifenesin; pseudoephedrine should be given cautiously to women who are breast-feeding. The decision should be made as to whether to discontinue breast-feeding or discontinue the product based upon the importance of the drug to the mother.

    Geriatric

    Geriatric patients 60 years and older are more likely to have decreased renal clearance of pseudoephedrine as well as adverse reactions to sympathomimetic amines. In general, dose selection for geriatric patients should be cautious, usually starting at the low end of the dosing range. According to the Beers Criteria, oral decongestants such as pseudoephedrine are considered potentially inappropriate medications (PIMs) for use in geriatric patients with insomnia and should be avoided due to the potential for drug-induced CNS stimulant effects. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities. According to the OBRA guidelines, cough, cold, and allergy medications should be used only for a limited duration (less than 14 days) unless there is documented evidence of enduring symptoms that cannot otherwise be alleviated and for which a cause cannot be identified and corrected. In addition, oral decongestants, such as pseudoephedrine, should be used cautiously in patients who have insomnia or hypertension. Oral decongestants may cause dizziness, nervousness, insomnia, palpitations, urinary retention, and elevated blood pressure.

    ADVERSE REACTIONS

    Severe

    seizures / Delayed / Incidence not known
    stroke / Early / Incidence not known
    myocardial infarction / Delayed / Incidence not known
    arrhythmia exacerbation / Early / Incidence not known

    Moderate

    hallucinations / Early / Incidence not known
    psychosis / Early / Incidence not known
    sinus tachycardia / Rapid / Incidence not known
    premature ventricular contractions (PVCs) / Early / Incidence not known
    angina / Early / Incidence not known
    hypertension / Early / Incidence not known
    palpitations / Early / Incidence not known
    supraventricular tachycardia (SVT) / Early / Incidence not known

    Mild

    restlessness / Early / Incidence not known
    anxiety / Delayed / Incidence not known
    insomnia / Early / Incidence not known
    drowsiness / Early / Incidence not known
    headache / Early / Incidence not known
    dizziness / Early / Incidence not known

    DRUG INTERACTIONS

    Acarbose: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Acebutolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Acetaminophen; Butalbital; Caffeine: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Acetaminophen; Butalbital; Caffeine; Codeine: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Acetaminophen; Caffeine; Dihydrocodeine: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Acetaminophen; Caffeine; Phenyltoloxamine; Salicylamide: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Acetaminophen; Dextromethorphan; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Acetaminophen; Guaifenesin; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Acetazolamide: (Moderate) Acetazolamide and methazolamide can decrease excretion and enhance the effects of pseudoephedrine. Carbonic anhydrase inhibitors increase the alkalinity of the urine, thereby increasing the amount of nonionized pseudoephedrine available for renal tubular reabsorption. Use caution if acetazolamide or methazolamide is coadministered; monitor for excessive pseudoephedrine-related adverse effects.
    Albiglutide: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Albuterol: (Major) Caution and close observation should be used when albuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Albuterol; Ipratropium: (Major) Caution and close observation should be used when albuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Aliskiren; Amlodipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Alkalinizing Agents: (Minor) Pseudoephedrine renal elimination is susceptible to changes in urinary pH. Urinary alkalinizers allow for increased tubular reabsorption of pseudoephedrine. Concomitant administration of pseudoephedrine with urinary alkalinizers may increase the likelihood of pseudoephedrine adverse reactions.
    Alogliptin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving alogliptin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Alogliptin; Metformin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving alogliptin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Alogliptin; Pioglitazone: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving alogliptin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Alpha-blockers: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by alpha-blockers. Monitor blood pressure and heart rate.
    Alpha-glucosidase Inhibitors: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Aluminum Hydroxide: (Minor) It appears that antacids containing alluminum hydroxide may increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If aluminum-based antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Aluminum Hydroxide; Magnesium Carbonate: (Minor) It appears that antacids containing alluminum hydroxide may increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If aluminum-based antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Aluminum Hydroxide; Magnesium Hydroxide: (Minor) It appears that antacids containing alluminum hydroxide may increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If aluminum-based antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Minor) It appears that antacids containing alluminum hydroxide may increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If aluminum-based antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Aluminum Hydroxide; Magnesium Trisilicate: (Minor) It appears that antacids containing alluminum hydroxide may increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If aluminum-based antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Amlodipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Amlodipine; Atorvastatin: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Amlodipine; Benazepril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Amlodipine; Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Amlodipine; Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Amlodipine; Olmesartan: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Amlodipine; Telmisartan: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Amlodipine; Valsartan: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Ammonium Chloride: (Minor) Pseudoephedrine renal elimination is susceptible to changes in urinary pH. Ammonium chloride, by acidifying the urine, increases the elimination of pseudoephedrine.
    Amoxapine: (Major) Concomitant use of amoxapine with sympathomimetics should be avoided whenever possible; use with caution when concurrent use cannot be avoided. One drug information reference suggests that cyclic antidepressants potentiate the pharmacologic effects of direct-acting sympathomimetics, but decrease the pressor response to indirect-acting sympathomimetics, however, the data are not consistent.
    Angiotensin II receptor antagonists: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin II receptor antagonists. Monitor heart rate and blood pressure.
    Angiotensin-converting enzyme inhibitors: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Arformoterol: (Moderate) Caution and close observation should be used when arformoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Aspirin, ASA; Butalbital; Caffeine: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Aspirin, ASA; Butalbital; Caffeine; Codeine: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Aspirin, ASA; Caffeine; Dihydrocodeine: (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Atenolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Atenolol; Chlorthalidone: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Atomoxetine: (Major) Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with drugs with sympathomimetic activity such as pseudoephedrine. Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if sympathomimetics are coadministered with atomoxetine.
    Atropine: (Major) Atropine blocks the vagal reflex bradycardia caused by pseudoephedrine, and increases its pressor effect. Patients need to be asked whether they have taken pseudoephedrine before receiving atropine.
    Atropine; Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Major) Atropine blocks the vagal reflex bradycardia caused by pseudoephedrine, and increases its pressor effect. Patients need to be asked whether they have taken pseudoephedrine before receiving atropine.
    Atropine; Difenoxin: (Major) Atropine blocks the vagal reflex bradycardia caused by pseudoephedrine, and increases its pressor effect. Patients need to be asked whether they have taken pseudoephedrine before receiving atropine.
    Atropine; Diphenoxylate: (Major) Atropine blocks the vagal reflex bradycardia caused by pseudoephedrine, and increases its pressor effect. Patients need to be asked whether they have taken pseudoephedrine before receiving atropine.
    Atropine; Edrophonium: (Major) Atropine blocks the vagal reflex bradycardia caused by pseudoephedrine, and increases its pressor effect. Patients need to be asked whether they have taken pseudoephedrine before receiving atropine.
    Atropine; Hyoscyamine; Phenobarbital; Scopolamine: (Major) Atropine blocks the vagal reflex bradycardia caused by pseudoephedrine, and increases its pressor effect. Patients need to be asked whether they have taken pseudoephedrine before receiving atropine.
    Azilsartan; Chlorthalidone: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Belladonna Alkaloids; Ergotamine; Phenobarbital: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Benazepril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Bendroflumethiazide; Nadolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Beta-blockers: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Betaxolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Bethanechol: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
    Bisoprolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Bisoprolol; Hydrochlorothiazide, HCTZ: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Bretylium: (Major) The action of sympathomimetics may be enhanced in patients receiving bretylium. Administration of bretylium causes an initial surge in catecholamine release from nerve terminals. Prolonged therapy with bretylium prevents release of the neurotransmitter but adrenergic stores of norepinephrine are not depleted. Inhibition of the release of norepinephrine eventually leads to increased receptor sensitivity. Increased sensitivity to sympathomimetics, such as pseudoephedrine, should be expected in patients receiving bretylium.
    Brimonidine; Timolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Bromocriptine: (Moderate) One case report documented worsening headache, hypertension, premature ventricular complexes, and ventricular tachycardia in a post-partum patient receiving bromocriptine for lactation suppression who was subsequently prescribed acetaminophen; dichloralphenazone; isometheptene for a headache. A second case involved a post-partum patient receiving bromocriptine who was later prescribed phenylpropanolamine; guaifenesin and subsequently developed hypertension, tachycardia, seizures, and cerebral vasospasm. Also, ergot alkaloids, which are chemically related to bromocriptine, should not be administered with other vasoconstrictors. Therefore, until more data become available, concurrent use of bromocriptine and some sympathomimetics such as vasopressors (e.g., norepinephrine, dopamine, phenylephrine), cocaine, epinephrine, phenylpropanolamine, ephedra, ma huang, ephedrine, pseudoephedrine, amphetamines, and phentermine should be approached with caution.
    Brompheniramine; Carbetapentane; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Budesonide; Formoterol: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Bumetanide: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Bupropion: (Major) Bupropion is associated with a dose-related risk of seizures. Excessive use of psychostimulants, including non-prescription stimulants and weight loss medications, is associated with an increased seizure risk; seizures may be more likely to occur in these patients during concurrent use of bupropion. Patients should be closely monitored if these combinations are necessary.
    Bupropion; Naltrexone: (Major) Bupropion is associated with a dose-related risk of seizures. Excessive use of psychostimulants, including non-prescription stimulants and weight loss medications, is associated with an increased seizure risk; seizures may be more likely to occur in these patients during concurrent use of bupropion. Patients should be closely monitored if these combinations are necessary.
    Cabergoline: (Minor) In theory, an interaction is possible between cabergoline, an ergot derivative, and some sympathomimetic agents such as vasopressors (e.g., norepinephrine, dopamine, phenylephrine), cocaine, epinephrine, phenylpropanolamine, ephedra, ma huang, pseudoephedrine, amphetamines, and phentermine. Use of the ergot derivative bromocriptine for lactation suppression in conjunction with a sympathomimetic (i.e., isometheptene or phenylpropanolamine) for other therapeutic uses has resulted in adverse effects such as worsening headache, hypertension, ventricular tachycardia, seizures, sudden loss of vision, and cerebral vasospasm.
    Caffeine: (Moderate) Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Caffeine; Ergotamine: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics. (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants or psychostimulants; caffeine should be avoided or used cautiously. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
    Calcium Carbonate: (Minor) It appears that antacids increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Calcium Carbonate; Magnesium Hydroxide: (Minor) It appears that antacids increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Calcium Carbonate; Risedronate: (Minor) It appears that antacids increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Calcium; Vitamin D: (Minor) It appears that antacids increase pseudoephedrine plasma concentrations. This interaction can be avoided by separating the administration of pseudoephedrine and antacids by 1 to 2 hours. If antacids are used on a regular basis, an alternative to pseudoephedrine may be considered.
    Calcium-channel blockers: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Canagliflozin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving canagliflozin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Canagliflozin; Metformin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving canagliflozin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Captopril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Carbetapentane; Chlorpheniramine; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Carbetapentane; Diphenhydramine; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Carbetapentane; Guaifenesin; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Carbetapentane; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Carbetapentane; Phenylephrine; Pyrilamine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Carbinoxamine; Hydrocodone; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Carbinoxamine; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Cardiac glycosides: (Major) Concomitant use of cardiac glycosides with sympathomimetics can cause arrhythmias because sympathomimetics enhance ectopic pacemaker activity. Caution is warranted during co-administration of digoxin and sympathomimetics.
    Carteolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Carvedilol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Chlophedianol; Guaifenesin; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Chlorothiazide: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Chlorpheniramine; Dextromethorphan; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Chlorpheniramine; Hydrocodone; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Chlorpheniramine; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Chlorthalidone: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Chlorthalidone; Clonidine: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) Sympathomimetics, such as pseudoephedrine, can antagonize the antihypertensive effects of clonidine when administered concomitantly. Patients should be monitored for loss of blood pressure control.
    Clevidipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Clonidine: (Moderate) Sympathomimetics, such as pseudoephedrine, can antagonize the antihypertensive effects of clonidine when administered concomitantly. Patients should be monitored for loss of blood pressure control.
    Codeine; Phenylephrine; Promethazine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Colchicine: (Minor) The response to sympathomimetics may be enhanced by colchicine.
    Dapagliflozin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving dapagliflozin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Dapagliflozin; Metformin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving dapagliflozin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Dapagliflozin; Saxagliptin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving dapagliflozin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Desiccated Thyroid: (Moderate) Sympathomimetic amines should be used with caution in patients with thyrotoxicosis since these patients are unusually responsive to sympathomimetic amines. Based on the cardiovascular stimulatory effects of sympathomimetic drugs, the concomitant use of sympathomimetics and thyroid hormones can enhance the effects on the cardiovascular system. Patients with coronary artery disease have an increased risk of coronary insufficiency from either agent. Concomitant use of these agents may increase this risk further. In addition, dopamine at a dose of >= 1 mcg/kg/min and dopamine agonists (e.g., apomorphine, bromocriptine, levodopa, pergolide, pramipexole, ropinirole, rotigotine) may result in a transient reduction in TSH secretion. The reduction in TSH secretion is not sustained; hypothyroidism does not occur.
    Dextromethorphan; Diphenhydramine; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Dextromethorphan; Guaifenesin; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Digitoxin: (Major) Concomitant use of cardiac glycosides with sympathomimetics can cause arrhythmias because sympathomimetics enhance ectopic pacemaker activity. Caution is warranted during co-administration of digoxin and sympathomimetics.
    Digoxin: (Major) Concomitant use of cardiac glycosides with sympathomimetics can cause arrhythmias because sympathomimetics enhance ectopic pacemaker activity. Caution is warranted during co-administration of digoxin and sympathomimetics.
    Dihydroergotamine: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Diltiazem: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Diphenhydramine; Hydrocodone; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Diphenhydramine; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Dopamine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Dorzolamide; Timolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Dronabinol, THC: (Moderate) Concurrent use of dronabinol, THC with sympathomimetics may result in additive hypertension, tachycardia, and possibly cardiotoxicity. Dronabinol, THC has been associated with occasional hypotension, hypertension, syncope, and tachycardia. In a study of 7 adult males, combinations of IV cocaine and smoked marijuana, 1 g marijuana cigarette, 0 to 2.7% delta-9-THC, increased the heart rate above levels seen with either agent alone, with increases plateauing at 50 bpm.
    Droxidopa: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Dulaglutide: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Dyphylline: (Major) Coadministration of dyphylline with sympathomimetics should be approached with caution. Coadministration may lead to adverse effects, such as tremors, insomnia, seizures, or cardiac arrhythmias, and should be avoided if possible.
    Dyphylline; Guaifenesin: (Major) Coadministration of dyphylline with sympathomimetics should be approached with caution. Coadministration may lead to adverse effects, such as tremors, insomnia, seizures, or cardiac arrhythmias, and should be avoided if possible.
    Empagliflozin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving empagliflozin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Empagliflozin; Linagliptin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving empagliflozin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving linagliptin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Empagliflozin; Metformin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving empagliflozin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Enalapril, Enalaprilat: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Enalapril; Felodipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Ephedrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Epoprostenol: (Major) Sympathomimetics can antagonize the antihypertensive effects of adrenergic agonists when administered concomitantly. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Ergoloid Mesylates: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Ergonovine: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Ergot alkaloids: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Ergotamine: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Esmolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Ethacrynic Acid: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Exenatide: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Felodipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Fluticasone; Salmeterol: (Major) Caution and close observation should also be used when salmeterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Fluticasone; Umeclidinium; Vilanterol: (Moderate) Administer sympathomimetics with caution with beta-agonists such as vilanterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use. Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects.
    Fluticasone; Vilanterol: (Moderate) Administer sympathomimetics with caution with beta-agonists such as vilanterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use. Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects.
    Formoterol: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Formoterol; Mometasone: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Fosinopril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Furosemide: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Ginger, Zingiber officinale: (Minor) In vitro studies have demonstrated the positive inotropic effects of certain gingerol constituents of ginger; but it is unclear if whole ginger root exhibits these effects clinically in humans. It is theoretically possible that excessive doses of ginger could affect the action of vasopressors like pseudoephedrine; however, no clinical data are available.
    Glipizide; Metformin: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Glyburide; Metformin: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Glycopyrrolate; Formoterol: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Green Tea: (Moderate) Some, but not all, green tea products contain caffeine. Caffeine should be avoided or used cautiously with pseudoephedrine. CNS stimulants and sympathomimetics are associated with adverse effects such as nervousness, irritability, insomnia, and cardiac arrhythmias.
    Guaifenesin; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Guanabenz: (Major) Sympathomimetics can antagonize the antihypertensive effects of adrenergic agonists when administered concomitantly. Patients should be monitored for loss of blood pressure control.
    Guarana: (Major) Caffeine, an active constituent of guarana, is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Use of guarana should be avoided with amphetamine, dextroamphetamine, methylphenidate, modafinil, pemoline, pseudoephedrine, beta-agonists or other sympathomimetics. When combined with any of these medications, nervousness, irritability, insomnia, and/or cardiac arrhythmias may result.
    Halogenated Anesthetics: (Major) Avoid administration of pseudoephedrine products to patients who have recently undergone, or will soon undergo, a procedure or treatment that requires general anesthesia. Specifically, halogenated anesthetics may sensitize the myocardium to the effects of sympathomimetics, including pseudoephedrine.
    Haloperidol: (Moderate) Non-cardiovascular drugs with alpha-blocking activity such as haloperidol directly counteract the effects of pseudoephedrine and can counter the desired pharmacologic effect. They also can be used to treat excessive pseudoephedrine-induced hypertension.
    Hydralazine; Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Irbesartan: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Lisinopril: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Hydrochlorothiazide, HCTZ; Losartan: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Methyldopa: (Major) Sympathomimetics, such as pseudoephedrine, can antagonize the antihypertensive effects of methyldopa when administered concomitantly. Blood pressure should be monitored closely to confirm that the desired antihypertensive effect is achieved. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Metoprolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Propranolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed. (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Quinapril: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Hydrochlorothiazide, HCTZ; Spironolactone: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Telmisartan: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Triamterene: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Hydrocodone; Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Iloprost: (Major) Sympathomimetics can antagonize the antihypertensive effects of adrenergic agonists when administered concomitantly. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
    Incretin Mimetics: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Indacaterol: (Moderate) Clinically significant cardiovascular effects and fatalities have been reported in association with excessive use of inhaled sympathomimetic drugs. Caution and close observation is needed if indacaterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Indacaterol; Glycopyrrolate: (Moderate) Clinically significant cardiovascular effects and fatalities have been reported in association with excessive use of inhaled sympathomimetic drugs. Caution and close observation is needed if indacaterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Indapamide: (Moderate) Sympathomimetics can antagonize the antihypertensive effects of vasodilators when administered concomitantly. Patients should be monitored to confirm that the desired antihypertensive effect is achieved.
    Insulin Degludec; Liraglutide: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Insulin Glargine; Lixisenatide: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Insulins: (Moderate) Monitor patients receiving insulin closely for worsening glycemic control when sympathomimetic agents are instituted. Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism.
    Isocarboxazid: (Severe) In general, all types of sympathomimetics and psychostimulants should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and even respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
    Isradipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Labetalol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Levalbuterol: (Major) Caution and close observation should be used when albuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Levobetaxolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Levobunolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Levothyroxine: (Moderate) Sympathomimetic amines should be used with caution in patients with thyrotoxicosis since these patients are unusually responsive to sympathomimetic amines. Based on the cardiovascular stimulatory effects of sympathomimetic drugs, the concomitant use of sympathomimetics and thyroid hormones can enhance the effects on the cardiovascular system. Patients with coronary artery disease have an increased risk of coronary insufficiency from either agent. Concomitant use of these agents may increase this risk further. In addition, dopamine at a dose of >= 1 mcg/kg/min and dopamine agonists (e.g., apomorphine, bromocriptine, levodopa, pergolide, pramipexole, ropinirole, rotigotine) may result in a transient reduction in TSH secretion. The reduction in TSH secretion is not sustained; hypothyroidism does not occur.
    Linagliptin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving linagliptin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted.
    Linagliptin; Metformin: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving linagliptin should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Linezolid: (Moderate) Linezolid may enhance the hypertensive effect of pseudoephedrine. Closely monitor for increased blood pressure during coadministration. Linezolid is an antibiotic that is also a weak, reversible nonselective inhibitor of monoamine oxidase (MAO). Therefore, linezolid has the potential for interaction with adrenergic agents, such as pseudoephedrine.
    Liothyronine: (Moderate) Sympathomimetic amines should be used with caution in patients with thyrotoxicosis since these patients are unusually responsive to sympathomimetic amines. Based on the cardiovascular stimulatory effects of sympathomimetic drugs, the concomitant use of sympathomimetics and thyroid hormones can enhance the effects on the cardiovascular system. Patients with coronary artery disease have an increased risk of coronary insufficiency from either agent. Concomitant use of these agents may increase this risk further. In addition, dopamine at a dose of >= 1 mcg/kg/min and dopamine agonists (e.g., apomorphine, bromocriptine, levodopa, pergolide, pramipexole, ropinirole, rotigotine) may result in a transient reduction in TSH secretion. The reduction in TSH secretion is not sustained; hypothyroidism does not occur.
    Liotrix: (Moderate) Sympathomimetic amines should be used with caution in patients with thyrotoxicosis since these patients are unusually responsive to sympathomimetic amines. Based on the cardiovascular stimulatory effects of sympathomimetic drugs, the concomitant use of sympathomimetics and thyroid hormones can enhance the effects on the cardiovascular system. Patients with coronary artery disease have an increased risk of coronary insufficiency from either agent. Concomitant use of these agents may increase this risk further. In addition, dopamine at a dose of >= 1 mcg/kg/min and dopamine agonists (e.g., apomorphine, bromocriptine, levodopa, pergolide, pramipexole, ropinirole, rotigotine) may result in a transient reduction in TSH secretion. The reduction in TSH secretion is not sustained; hypothyroidism does not occur.
    Liraglutide: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Lisinopril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Lixisenatide: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Loop diuretics: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Macitentan: (Major) Sympathomimetics can antagonize the effects of vasodilators when administered concomitantly. Patients should be monitored for reduced efficacy if taking macitentan with a sympathomimetic.
    Maprotiline: (Major) Sympathomimetics may interact with maprotiline, resulting in severe cardiovascular effects including arrhythmias, severe hypertension, hyperpyrexia, and/or severe headaches.
    Meglitinides: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Metaproterenol: (Major) Caution and close observation should also be used when metaproterenol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Metformin: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Metformin; Pioglitazone: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Metformin; Repaglinide: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Metformin; Rosiglitazone: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Metformin; Saxagliptin: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Metformin; Sitagliptin: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted. (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Methazolamide: (Moderate) Methazolamide can decrease the urinary excretion and enhance the clinical effects of pseudoephedrine. Use caution if methazolamide is coadministered; monitor for excessive pseudoephedrine-related adverse effects.
    Methyclothiazide: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Methyldopa: (Major) Sympathomimetics, such as pseudoephedrine, can antagonize the antihypertensive effects of methyldopa when administered concomitantly. Blood pressure should be monitored closely to confirm that the desired antihypertensive effect is achieved.
    Methylergonovine: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Methysergide: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Metolazone: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Metoprolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Midodrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Miglitol: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Moexipril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Monoamine oxidase inhibitors: (Severe) In general, all types of sympathomimetics and psychostimulants should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and even respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
    Nabilone: (Moderate) Concurrent use of nabilone with sympathomimetics (e.g., amphetamine or cocaine) may result in additive hypertension, tachycardia, and possibly cardiotoxicity. In a study of 7 adult males, combinations of cocaine (IV) and smoked marijuana (1 g marijuana cigarette, 0 to 2.7% delta-9-THC) increased the heart rate above levels seen with either agent alone, with increases reaching a plateau at 50 bpm.
    Nadolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Nebivolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Nebivolol; Valsartan: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Nicardipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Nicotine: (Minor) Vasoconstricting nasal decongestants such as oxymetazoline, phenylephrine, pseudoephedrine, and tetrahydrozoline prolong the time to peak effect of nasally administered nicotine (i.e. nicotine nasal spray); however, no dosage adjustments are recommended.
    Nifedipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Nimodipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Nisoldipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Nitrates: (Major) Concomitant use of nitrates with sympathomimetics can result in antagonism of the antianginal effects of nitrates. In addition, amyl nitrite can block the alpha-adrenergic effects of epinephrine, possibly precipitating tachycardia and severe hypotension.
    Norepinephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Penbutolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Pergolide: (Severe) Ergot alkaloids should not be administered with pseudoephedrine since combining these agents may produce a synergistic increase in blood pressure. There is also an additive risk of peripheral ischemia or gangrene. Of note, at therapeutic doses, ergoloid mesylates lack the vasoconstrictor properties of the natural ergot alkaloids; therefore, ergoloid mesylates are not expected to interact with sympathomimetics.
    Perindopril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Perindopril; Amlodipine: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Phenelzine: (Severe) In general, all types of sympathomimetics and psychostimulants should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and even respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
    Phenylephrine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Phenylephrine; Promethazine: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Pindolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Pirbuterol: (Moderate) Caution and close observation should also be used when pirbuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Potassium-sparing diuretics: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Pramlintide: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Procarbazine: (Major) Because procarbazine exhibits some monoamine oxidase inhibitory (MAOI) activity, sympathomimetic drugs should be avoided. As with MAOIs, the use of a sympathomimetic drug with procarbazine may precipitate hypertensive crisis or other serious side effects. In the presence of MAOIs, drugs that cause release of norepinephrine induce severe cardiovascular and cerebrovascular responses. In general, do not use a sympathomimetic drug unless clinically necessary (e.g., medical emergencies, agents like dopamine) within the 14 days prior, during or 14 days after procarbazine therapy. If use is necessary within 2 weeks of the MAOI drug, in general the initial dose of the sympathomimetic agent must be greatly reduced. Patients should be counseled to avoid non-prescription (OTC) decongestants and other drug products, weight loss products, and energy supplements that contain sympathomimetic agents.
    Propranolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Quinapril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Racepinephrine: (Major) Racepinephrine is a sympathomimetic drug with agonist actions at both the alpha and beta receptors. Patients using racepinephrine inhalation are advised to avoid other non-prescription products containing sympathomimetics since additive adverse effects on the cardiovascular and nervous system are possible, some which may be undesirable. Side effects such as nausea, tremor, nervousness, difficulty with sleep, and increased heart rate or blood pressure may be additive. Patients should avoid use of non-prescription decongestants, such as phenylephrine and pseudoephedrine, while using racepinephrine inhalations. Patients should avoid dietary supplements containing ingredients that are reported or claimed to have a stimulant or weight-loss effect, such as ephedrine and ephedra, Ma huang, and phenylpropanolamine. Patients taking prescription sympathomimetic or stimulant medications (including amphetamines, methylphenidate, dexmethylphenidate, isometheptane, epinephrine) should seek health care professional advice prior to the use of racepinephrine inhalations; consider therapeutic alternatives to racepinephrine for these patients.
    Ramipril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Rasagiline: (Moderate) The concomitant use of rasagiline and sympathomimetics was not allowed in clinical studies; therefore, caution is advised during concurrent use of rasagiline and sympathomimetics including stimulants for ADHD and weight loss, non-prescription nasal, oral, and ophthalmic decongestants, and weight loss dietary supplements containing Ephedra. Although sympathomimetics are contraindicated for use with other non-selective monoamine oxidase inhibitors (MAOIs), hypertensive reactions generally are not expected to occur during concurrent use with rasagiline because of the selective monoamine oxidase-B (MAO-B) inhibition of rasagiline at manufacturer recommended doses. One case of elevated blood pressure has been reported in a patient during concurrent use of the recommended dose of rasagiline and ophthalmic tetrahydrozoline. One case of hypertensive crisis has been reported in a patient taking the recommended dose of another MAO-B inhibitor, selegiline, in combination with ephedrine. It should be noted that the MAO-B selectivity of rasagiline decreases in a dose-related manner as increases are made above the recommended daily dose and interactions with sympathomimetics may be more likely to occur at these higher doses.
    Reserpine: (Major) The cardiovascular effects of sympathomimetics, such as pseudoephedrine, may reduce the antihypertensive effects produced by reserpine. Blood pressure and heart rates should be monitored closely to confirm that the desired antihypertensive effect is achieved.
    Riociguat: (Major) Sympathomimetics can antagonize the effects of vasodilators when administered concomitantly. Patients should be monitored for reduced efficacy if taking riociguat with a sympathomimetic.
    Safinamide: (Moderate) Severe hypertensive reactions, including hypertensive crisis, have been reported in patients taking monoamine oxidase inhibitors (MAOIs), such as safinamide concurrently with sympathomimetic medications, such as pseudoephedrine. If concomitant use of safinamide and pseudoephedrine is necessary, monitor for hypertension and hypertensive crisis.
    Salmeterol: (Major) Caution and close observation should also be used when salmeterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
    Saxagliptin: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Selegiline: (Severe) In general, all types of sympathomimetics and psychostimulants should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and even respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
    Selexipag: (Major) Sympathomimetics can antagonize the effects of vasodilators when administered concomitantly. Patients should be monitored for reduced efficacy if taking selexipag with a sympathomimetic.
    Sibutramine: (Major) Concurrent use of sibutramine with other serotonergic agents may increase the potential for serotonin syndrome or neuroleptic malignant syndrome-like reactions. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Simvastatin; Sitagliptin: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Sitagliptin: (Moderate) Sympathomimetics may increase blood glucose concentrations. Monitor for loss of diabetic control when therapy with sympathomimetic agents is instituted. Also, adrenergic medications may increase glucose uptake by muscle cells and may potentiate the actions of some antidiabetic agents. Monitor blood glucose to avoid hypoglycemia or hyperglycemia.
    Sotalol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    St. John's Wort, Hypericum perforatum: (Major) St. John's wort may have MAOI-like activities, and could potentially increase the cardiac stimulation and vasopressor effects of the sympathomimetics. St. John's wort should be used cautiously with any sympathomimetic agent.
    Sulfonylureas: (Moderate) Endogenous epinephrine is released in response to hypoglycemia; epinephrine, through stimulation of alpha- and beta- receptors, increases hepatic glucose production and glycogenolysis and inhibits insulin secretion in order to increase serum glucose concentrations. A pharmacodynamic interaction may occur when pseudoephedrine and other sympathomimetics are administered to patients as these agents may increase blood glucose concentrations by a similar mechanism. Patients receiving sulfonylureas should be closely monitored for loss of diabetic control when therapy with sympathomimetic agents is instituted. Fenfluramine and dexfenfluramine may potentiate the actions of some antidiabetic agents via increasing glucose uptake by muscle cells. Monitor patients taking either of these drugs in combination with glyburide for hypoglycemia.
    Terbutaline: (Major) Concomitant use of sympathomimetics with beta-agonists might result in additive cardiovascular effects such as increased blood pressure and heart rate.
    Theophylline, Aminophylline: (Moderate) Concurrent administration of theophylline or aminophylline with some sympathomimetics can produce excessive stimulation and effects such as nervousness, irritability, or insomnia. (Moderate) Concurrent administration of theophylline or aminophylline with some sympathomimetics can produce excessive stimulation and effects such as nervousness, irritability, or insomnia. Seizures or cardiac arrhythmias are also possible.
    Thiazide diuretics: (Moderate) Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly.
    Thiazolidinediones: (Moderate) Pseudoephedrine may increase blood sugar via stimulation of beta2 receptors which leads to increased glycogenolysis. A pharmacodynamic interaction with antidiabetic agents may occur. Patients receiving antidiabetic agents should be closely monitored for loss of diabetic control when therapy with pseudoephedrine is instituted.
    Thyroid hormones: (Moderate) Sympathomimetic amines should be used with caution in patients with thyrotoxicosis since these patients are unusually responsive to sympathomimetic amines. Based on the cardiovascular stimulatory effects of sympathomimetic drugs, the concomitant use of sympathomimetics and thyroid hormones can enhance the effects on the cardiovascular system. Patients with coronary artery disease have an increased risk of coronary insufficiency from either agent. Concomitant use of these agents may increase this risk further. In addition, dopamine at a dose of >= 1 mcg/kg/min and dopamine agonists (e.g., apomorphine, bromocriptine, levodopa, pergolide, pramipexole, ropinirole, rotigotine) may result in a transient reduction in TSH secretion. The reduction in TSH secretion is not sustained; hypothyroidism does not occur.
    Timolol: (Major) Sympathomimetics, such as amphetamines, phentermine, and decongestants (e.g., pseudoephedrine, phenylephrine), and many other drugs, may increase both systolic and diastolic blood pressure and may counteract the activity of the beta-blockers. Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed.
    Torsemide: (Moderate) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by diuretics. Well-controlled hypertensive patients receiving pseudoephedrine at recommended doses do not appear at high risk for significant elevations in blood pressure; however, increased blood pressure (especially systolic hypertension) has been reported in some patients.
    Trandolapril: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure.
    Trandolapril; Verapamil: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by angiotensin-converting enzyme inhibitors. Monitor heart rate and blood pressure. (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Tranylcypromine: (Severe) In general, all types of sympathomimetics and psychostimulants should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and even respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
    Tricyclic antidepressants: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to certain sympathomimetic agents, such as pseudoephedrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat.
    Umeclidinium; Vilanterol: (Moderate) Administer sympathomimetics with caution with beta-agonists such as vilanterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use. Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects.
    Vasodilators: (Major) Sympathomimetics can antagonize the antihypertensive effects of vasodilators when administered concomitantly. Also, vasodilators can antagonize pressor responses to epinephrine. Patients should be monitored to confirm that the desired antihypertensive effect is achieved.
    Vasopressors: (Major) Pseudoephedrine can potentiate the effects and increase the toxicity of other sympathomimetics by adding to their sympathomimetic activity. Although no data are available, pseudoephedrine should be used cautiously in patients using significant quantities of other sympathomimetics.
    Verapamil: (Moderate) The cardiovascular effects of pseudoephedrine may reduce the antihypertensive effects produced by calcium-channel blockers. Monitor blood pressure and heart rate.
    Yohimbine: (Major) At high doses, yohimbine may nonselectively inhibit MAO and also, at normal doses, activates the sympathetic nervous system. Traditional MAOIs can cause serious adverse effects when taken concomitantly with sympathomimetics.

    PREGNANCY AND LACTATION

    Pregnancy

    Both guaifenesin and pseudoephedrine are classified as pregnancy category C drugs. Adequate or well-controlled pregnancy studies have not been done in humans. Some sympathomimetic amines are associated with minor malformations in some animal species; however, human teratogenesis has not been suspected based on limited epidemiologic evidence. Use of guaifenesin; pseudoephedrine during pregnancy should be avoided unless the potential benefits outweigh the unknown potential risks to the fetus. When administered to pregnant women, product formulations that also contain ethanol or other drugs should not be used.

    It is not known whether guaifenesin is excreted into human breast milk. Pseudoephedrine is excreted into breast milk, with peak milk concentrations occur 1—1.5 hours after a maternal oral dosage. Peak milk concentrations of pseudoephedrine usually exceed those of maternal plasma. The total amount of pseudoephedrine (measured by AUC) in milk is 2—3 times that of plasma. However, only 0.5% of a maternal dose would probably be ingested by an infant during breast-feeding within any 24 hours. The American Academy of Pediatrics has considered the use of pseudoephedrine to be compatible with lactation. Lactating women may want to avoid breast-feeding during times of peak concentrations (i.e., within 1—2 hours after a dose) when possible. Sympathomimetic adverse effects (irritability, excessive crying, and altered sleeping patterns) have been reported in a breast-fed infant following maternal administration of pseudoephedrine; symptoms resolved within 12 hours of drug discontinuation. Guaifenesin; pseudoephedrine should be given cautiously to women who are breast-feeding. The decision should be made as to whether to discontinue breast-feeding or discontinue the product based upon the importance of the drug to the mother.

    MECHANISM OF ACTION

    Guaifenesin; pseudoephedrine delayed-release tablets have combined antitussive and sympathomimetic properties.
    •Guaifenesin: Guaifenesin reduces the adhesiveness and surface tension of respiratory tract secretions, thereby easing their expectoration. The expectorant effect can reduce cough frequency. The increased flow of less viscous secretions promotes ciliary action and changes a dry, nonproductive cough to one that is more productive and less frequent. Guaifenesin loosens and thins phlegm and bronchial secretions to ease expectoration. By reducing the viscosity and adhesiveness of secretions, guaifenesin increases the efficacy of the mucociliary mechanism in removing accumulated secretions from the upper and lower airway. Guaifenesin can also be beneficial for irritating, nonproductive coughs and for conditions in which thick mucous secretions are produced.
    •Pseudoephedrine: Pseudoephedrine is an agonist at both alpha- and, to a lesser degree, beta-adrenergic receptors. Like ephedrine, pseudoephedrine also has an indirect effect by releasing norepinephrine from its storage sites. By stimulating alpha-adrenergic receptors in the mucosa of the respiratory tract, pseudoephedrine shrinks swollen nasal mucous membranes; reduces tissue hyperemia, edema, and nasal congestion; and increases nasal airway patency. Also, drainage of sinus secretions is increased, and obstructed eustachian ostia may be opened. Oral administration of pseudoephedrine usually produces negligible effects on blood pressure. In some patients, especially those with preexisting cardiac disease receiving higher doses, pseudoephedrine may increase blood pressure or irritability of the heart muscle and may affect ventricular conduction.

    PHARMACOKINETICS

    Guaifenesin; pseudoephedrine combination products are administered orally. Various extended-release combinations are available which are formulated to provide therapeutic effects over the 12 hour dosing interval. Coadministration of guaifenesin with pseudoephedrine has no effect on the bioavailability or pharmacokinetics of either drug.
    Guaifenesin: Guaifenesin has a plasma half-life of approximately 1 hour. Guaifenesin is rapidly hydrolyzed (60% within seven hours) and then excreted in the urine, with beta-(2-methoxyphenoxy)-lactic acid as its major urinary metabolite. No unchanged drug could be detected in the urine following administration of oral guaifenesin. Excessive use of guaifenesin may result in urolithiasis; renal stones have been documented to contain beta-(2-methoxyphenoxy)-lactic acid and other guaifenesin metabolites.
    Pseudoephedrine: Pseudoephedrine is presumed to cross the placenta, blood brain barrier, and may be distributed into breast milk. Pseudoephedrine is incompletely metabolized in the liver to norpseudoephedrine, the primary active metabolite of the parent. The drug and metabolite are excreted in the urine; with 55—75% excreted as unchanged drug. The elimination half-life of the drug ranges from 9—16 hours dependent primarily upon urinary pH. The rate of urinary excretion is accelerated upon urinary acidification to a pH near 5. Upon alkalinization of the urine to a pH of approximately 8, some of the drug is reabsorbed into the kidney tubule and the rate of urinary excretion is slowed.

    Oral Route

    Guaifenesin: Guaifenesin is rapidly absorbed from the gastrointestinal tract.
    Pseudoephedrine: Pseudoephedrine duration of action is dependent upon the dose and the extended release formulation (12 or 24 hours).