What is the effect of Brompheniramine (antihistamine)-Pseudoephedrine (decongestant)?

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From the Guidelines

Brompheniramine-pseudoephedrine should be used with caution, especially in children under 6 years of age, due to the potential for serious side effects and limited efficacy in this age group, as noted in studies such as 1.

Overview of Brompheniramine-Pseudoephedrine

Brompheniramine-pseudoephedrine is a combination medication used to treat symptoms of the common cold, allergies, and upper respiratory infections. It contains brompheniramine, an antihistamine that reduces allergy symptoms like sneezing and itching, and pseudoephedrine, a decongestant that relieves nasal congestion.

Dosage and Administration

The typical adult dosage is one tablet or 5-10 mL of liquid formulation every 4-6 hours, not exceeding 4 doses in 24 hours. Children's dosing varies by age and weight, so parents should follow package instructions or physician guidance.

Mechanism of Action

This medication works because brompheniramine blocks histamine receptors to reduce allergic responses, while pseudoephedrine narrows blood vessels in the nasal passages to reduce swelling and congestion.

Side Effects and Precautions

Common side effects include drowsiness, dizziness, dry mouth, and nervousness. Users should avoid alcohol, driving, and operating machinery while taking this medication. Those with high blood pressure, heart disease, diabetes, thyroid disorders, glaucoma, or enlarged prostate should consult a healthcare provider before use, as should pregnant or breastfeeding women.

Special Considerations

  • Children under 6 years: The use of brompheniramine-pseudoephedrine in children under 6 years of age is not recommended due to the potential for serious side effects, including agitated psychosis, ataxia, hallucinations, and even death, as reported in studies such as 1 and 1.
  • Pseudoephedrine restrictions: The medication is available over-the-counter but may require ID in some locations due to pseudoephedrine restrictions.
  • Alternative options: For children under 6 years, alternative treatments such as second-generation antihistamines (e.g., cetirizine, desloratadine, fexofenadine, levocetirizine, and loratadine) may be considered, as they have been shown to be well-tolerated and have a good safety profile, as noted in 1.

From the FDA Drug Label

CLINICAL PHARMACOLOGY Brompheniramine maleate is a histamine antagonist, specifically an H1-receptor-blocking agent belonging to the alkylamine class of antihistamines. Pseudoephedrine acts on sympathetic nerve endings and also on smooth muscle, making it useful as a nasal decongestant. The nasal decongestant effect is mediated by the action of pseudoephedrine on α-sympathetic receptors, producing vasoconstriction of the dilated nasal arterioles

  • Brompheniramine is an antihistamine that competes with histamine for receptor sites on effector cells, and also has anticholinergic and sedative effects.
  • Pseudoephedrine is a nasal decongestant that acts on sympathetic nerve endings and smooth muscle to produce vasoconstriction of dilated nasal arterioles. The combination of brompheniramine and pseudoephedrine is used to provide relief from allergic responses and nasal congestion 2.

From the Research

Brompheniramine-Pseudoephedrine Interactions

  • Brompheniramine is an antihistamine that can increase serotonin levels via 5-HT reuptake inhibition, and its interaction with monoamine oxidase inhibitors (MAOIs) can be adverse 3.
  • Pseudoephedrine is a decongestant that is a sympathomimetic amine, and its use with MAOIs can also be problematic due to its potential to elevate blood pressure 3, 4.
  • The combination of brompheniramine and pseudoephedrine is often used to treat upper respiratory illnesses, but patients taking MAOIs should avoid such combinations to prevent adverse interactions 3, 4.

Pseudoephedrine Benefits and Risks

  • Pseudoephedrine is a drug with a long history of medical use, helpful in treating symptoms of the common cold and flu, sinusitis, asthma, and bronchitis 5.
  • However, its central nervous system (CNS) stimulant properties and structural similarity to amphetamine make it susceptible to non-medical use, such as an appetite reducer or a doping agent 5.
  • The misuse of pseudoephedrine is a concern, and its easier availability makes it a substitute for amphetamine or methamphetamine, as well as a substrate used in the production of these drugs 5.

Decongestant Selection

  • Decongestants, such as pseudoephedrine, are effective in reducing nasal congestion, regardless of its cause 4.
  • The selection of a decongestant should consider factors such as efficacy, bioavailability, and potential for rebound congestion, as well as the patient's medical history and current medications 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Selecting a decongestant.

Pharmacotherapy, 1993

Research

Pseudoephedrine-Benefits and Risks.

International journal of molecular sciences, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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