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RESPIRATORY SYSTEM › ANTIHISTAMINES FOR SYSTEMIC USE › ANTIHISTAMINES FOR SYSTEMIC USE › Other antihistamines for systemic use
pyrrobutamine
R06AX08
Forms & Strengths
- Combination oral tablets (often formulated with antihistamines like tripelennamine or sympathomimetics)
Adult Dosing
- 15 mg to 30 mg orally every 6 to 8 hours as needed for allergic conditions, typically in fixed-dose combination products
Pediatric Dosing
- Safety and efficacy in pediatric patients not well established; use generally avoided or restricted based on specific combination product labeling
Indications
- Symptomatic relief of allergic conditions including allergic rhinitis, urticaria, and vasomotor rhinitis
Mechanism of Action
- First-generation histamine H1-receptor antagonist that competitively inhibits free histamine, reducing allergic symptom manifestations and producing mild anticholinergic and sedative effects
Contraindications
- Hypersensitivity to pyrrobutamine or other components of the formulation
- Use in newborn or premature infants
- Use during acute asthma attacks
- Concurrent monoamine oxidase inhibitor (MAOI) therapy
Adverse Reactions
- Drowsiness and sedation
- Anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation)
- Dizziness and incoordination
- Gastrointestinal upset (nausea, vomiting)
Drug Interactions
- Central nervous system depressants (alcohol, opioids, sedatives, hypnotics) resulting in additive sedation
- Anticholinergic drugs (tricyclic antidepressants, atropine) leading to enhanced anticholinergic toxicity
- Monoamine oxidase inhibitors (MAOIs) which may prolong and intensify the anticholinergic effects of antihistamines
Curated Content: Needs Vetting Before Put to Clinical Use