Section 11 · Monograph
Meclizine
Reviewed Nov 2026FDA label
AntivertH1 antihistamine
- Forms
- Tab: 12.5, 25, 50mg
- Dose
- 25-100mg/day divided
- MOA
- Central anticholinergic/antihistamine, ↓vestibular activity
Indications
- Vertigo associated with diseases affecting the vestibular system in adultsFDA-labeled
- Nausea, vomiting and dizziness of motion sicknessFDA-labeled
Mechanism of Action
- First-generation H1 antihistamine with central anticholinergic activity that suppresses vestibular and emetic pathways
Full Dosing
Adult / usual
- Vestibular vertigo: 25-100mg/day in divided doses
- Motion sickness: 25-50mg one hour before travel
Contraindications
- Known hypersensitivity to meclizine
Drug Interactions
- Additive sedation and anticholinergic effects with CNS depressants and other anticholinergics
- CYP2D6 inhibitors may raise levels
Adverse Effects
- Drowsiness, dry mouth, blurred vision
- Urinary retention
- Confusion in older adults (Beers criteria — avoid when possible)
- Fatigue, headache
Monitoring Parameters
- Sedation and fall risk
- Anticholinergic burden in older adults
- Reassess diagnosis if vertigo persists or central red flags appear
Pregnancy & Lactation
- Generally considered low risk; limited data
- Small amounts in milk; may reduce milk supply