Does bromfed (brompheniramine) interact with bupropion, buspirone, or hydroxyzine?

Drug Interactions Between Bromfed (Brompheniramine) and Bupropion, Buspirone, or Hydroxyzine

Bromfed (brompheniramine) has a clinically significant interaction with bupropion due to seizure risk potentiation, requires caution with hydroxyzine due to additive anticholinergic and sedative effects, but has no documented significant interaction with buspirone.

Interaction with Bupropion

The combination of brompheniramine and bupropion should be avoided or used with extreme caution due to lowered seizure threshold. 1

• Bupropion lowers the seizure threshold, and antihistamines like brompheniramine can potentiate this effect 1
• The maximum dose of bupropion must not exceed 450 mg/day for immediate-release or 400 mg/day for sustained-release formulations to minimize seizure risk 2
• Bupropion is contraindicated in patients with seizure disorders, and adding medications that further lower the seizure threshold increases this risk 1
• Common side effects of bupropion include agitation, insomnia, headaches, and tremor, which may be exacerbated by antihistamine use 2
• If this combination must be used, start with the lowest effective doses of both medications and monitor closely for signs of seizure activity, including myoclonus, confusion, or altered mental status 2

Interaction with Buspirone

Brompheniramine can be safely combined with buspirone as there are no documented pharmacodynamic or pharmacokinetic interactions between these agents. 3, 4

• Buspirone acts primarily through 5-HT1A receptors with some affinity for DA2 autoreceptors and 5-HT2 receptors 4
• The mechanism of action does not overlap with antihistamines like brompheniramine 4
• Buspirone has minimal sedation effects and lacks anticonvulsant or muscle-relaxant properties 4
• The most common side effects of buspirone are headaches, dizziness, nervousness, and lightheadedness, which are not significantly potentiated by antihistamines 4
• Buspirone has a short elimination half-life of 2.1 hours and is metabolized to an active metabolite (1-PP) with a half-life of 6.1 hours 4

Interaction with Hydroxyzine

Exercise caution when combining brompheniramine with hydroxyzine due to additive anticholinergic effects and enhanced CNS depression. 3

• Both medications are antihistamines with anticholinergic properties, leading to additive side effects including dry mouth, urinary retention, constipation, and confusion (especially in elderly patients) 3
• Hydroxyzine causes significant drowsiness/sedation, which will be potentiated by brompheniramine 3
• The combination increases the risk of cognitive impairment and psychomotor slowing 3
• If this combination is necessary, reduce the dose of one or both agents by 25-50% and monitor for excessive sedation, falls risk (particularly in elderly), and anticholinergic toxicity 3
• Avoid this combination in elderly patients (>65 years) due to increased risk of delirium and falls 3

Clinical Monitoring Recommendations

• For bupropion combination: Monitor for seizure precursors (myoclonic jerks, confusion, tremor), avoid in patients with eating disorders or history of seizures 1, 2
• For hydroxyzine combination: Assess for excessive sedation, cognitive impairment, anticholinergic symptoms (dry mouth, urinary retention, constipation, blurred vision) 3
• For buspirone combination: Standard monitoring for each medication individually is sufficient; no additional precautions needed 4