Allegra

Generic name:

Fexofenadine

Drug class:

Second-generation H1 antihistamine

Dosage form:

Tablets (30 mg, 60 mg, 120 mg, 180 mg), extended-release tablets (120 mg, 180 mg), orally disintegrating tablets (30 mg), oral suspension (30 mg/5 mL)

Root of administration:

Oral

Dose:

Adults: 60 mg twice daily or 180 mg once daily; Children 6–11 years: 30 mg twice daily; Children 2–5 years: 30 mg once daily (suspension); Infants 6 months to 2 years: 15 mg twice daily (suspension); adjust dose in renal impairment.

Mechanism of action:

Fexofenadine selectively antagonizes peripheral histamine H1-receptors, inhibiting allergic inflammatory responses with minimal central nervous system penetration.

Drug usage cases:

• Seasonal allergic rhinitis
• Chronic idiopathic urticaria
• Allergic conjunctivitis (off-label)
• Other allergic skin conditions (off-label)

Drug contra indications:

• Hypersensitivity to fexofenadine or any formulation excipients

Side effects:

• Headache
• Drowsiness
• Nausea
• Dyspepsia
• Dizziness
• Fatigue
• Dry mouth
• Back pain
• Cough
• Rare: tachycardia, arrhythmia, urticaria
• Hepatic enzyme elevations (rare)

Warnings:

• Caution in renal impairment; dose reduction required
• May cause sedation and impair ability to drive or operate machinery
• Avoid coadministration with fruit juices (orange, apple, grapefruit) due to decreased absorption
• Use with caution in elderly patients
• May mask symptoms of other serious conditions (e.g., anaphylaxis)

Use during pregnancy or breastfeeding:

Pregnancy: Category C; animal studies have shown adverse effects, no adequate human studies; use only if potential benefit justifies risk.

Breastfeeding: Excreted in breast milk in small amounts; caution advised; monitor infant for sedation.