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RESPIRATORY SYSTEM › ANTIHISTAMINES FOR SYSTEMIC USE › ANTIHISTAMINES FOR SYSTEMIC USE › Other antihistamines for systemic use
quifenadine
R06AX31
Forms & Strengths
- Oral tablets: 50 mg
- Oral tablets: 100 mg
Adult Dosing
- Allergic rhinitis and urticaria: 50 mg to 100 mg orally 2 to 3 times daily
- Maximum daily dose: 300 mg
Pediatric Dosing
- Children over 12 years: 50 mg orally 1 to 2 times daily
- Children 3 to 12 years: 25 mg orally 2 times daily (if formulation permits) or directed by physician
Indications
- Allergic rhinitis (seasonal and perennial)
- Urticaria
- Allergic dermatoses accompanied by pruritus
Mechanism of Action
- Competitive antagonism of peripheral histamine H1 receptors
- Reduces histamine-induced smooth muscle contraction, increased vascular permeability, and pruritus
- Exhibits mild anticholinergic activity
Contraindications
- Hypersensitivity to quifenadine or any component of the formulation
- Severe hepatic impairment
- Severe renal impairment
Adverse Reactions
- Drowsiness
- Dizziness
- Dry mouth
- Mild gastrointestinal distress
- Fatigue
Drug Interactions
- Central nervous system depressants (alcohol, sedatives, hypnotics): May potentiate sedative effects
- Anticholinergic agents: May enhance anticholinergic adverse effects
- Hepatic enzyme inducers or inhibitors: Potential for altered plasma concentrations
Curated Content: Needs Vetting Before Put to Clinical Use