Meclizine
Meclizine hydrochloride
Also known as: Antivert · Bonine · Dramamine Less Drowsy · Meni-D · Agyrax · Ancolan · Antrizine · Bonamine · Calmonal · Dizmiss · SeaLegs · meclozine hydrochloride · meclizinium chloride · meclozini hydrochloridum · parachloramine hydrochloride
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Supportive treatment of peripheral vestibular disease | 25 mg per dog | PO | once daily | Treatment is usually unnecessary after 72-96 hours | 🌎 NA |
| Vestibular suppressant | 12.5-50 mg (total dose per dog) | PO | twice daily | — | 🌎 NA |
| Anti-emetic | 4 mg/kg | PO | once a day | — | 🌎 NA |
| Palliative treatment of vertigo | 25 mg per dog | PO | once daily | — | 🌎 NA |
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| General/Vestibular | 12.5 mg per cat | PO | once daily | — | 🌎 NA |
| General | 6.25 mg/5 kg of body weight | PO | Not specified | — | 🌎 NA |
| Anti-emetic | 4 mg/kg | PO | once a day | — | 🌎 NA |
| Palliative treatment of vertigo | 12.5 mg per cat | PO | once daily | — | 🌎 NA |
Small Mammals
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Rolling, torticollis, motion sickness (Rabbits) | 2-12 mg/kg | PO | once daily | — | 🌎 NA |
| Adjunctive treatment of torticollis, head tilt ('wry neck') (Rabbits) | 12.5 mg (total dose) | PO | q12-24h | — | 🌎 NA |
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Meclizine is a first-generation piperazine antihistamine widely used in veterinary medicine primarily for its antiemetic and anti-motion sickness properties.
- Clinical Utility: It is particularly effective for managing peripheral vestibular disease, vertigo, and motion sickness in dogs and cats.
- Additional Properties: Beyond its antihistamine activity, meclizine possesses mild CNS depressant, antispasmodic, and local anesthetic effects.
- Safety Profile: Generally well-tolerated, though its anticholinergic properties require cautious use in patients with specific comorbidities like glaucoma or urinary retention.
Mechanism of action
Meclizine acts primarily as an antagonist at central H1-receptors and muscarinic acetylcholine receptors.
- Vestibular Pathway: Blocks histaminergic and cholinergic signals originating from the vestibular apparatus → reduces stimulation of the Chemoreceptor Trigger Zone (CTZ) and the vomiting center in the medulla.
- Anticholinergic Activity: Central muscarinic antagonism contributes significantly to its efficacy against motion sickness and vertigo.
- CNS Depression: Causes generalized CNS depression, which may aid in its antiemetic and sedative effects.
Safety & warnings
Contraindications
- Hypersensitivity to meclizine
Adverse effects
- Sedation
- Dry mucous membranes
- Dry eyes
- Tachycardia
- Contradictory CNS stimulation
- Inappetence (especially in cats)
Precautions
Use with caution in patients with prostatic hypertrophy, bladder neck obstruction, severe cardiac failure, angle-closure glaucoma, or pyeloduodenal obstruction. Because it is an antihistamine, it may affect the results of skin tests using allergen extracts; do not use within 3-7 days before testing. May potentially inhibit lactation due to anticholinergic activity.
Drug interactions
Use with other CNS depressants may cause additive sedation
Other anticholinergic drugs may cause additive anticholinergic effects
Monitoring
- Clinical efficacy (reduction in vomiting, motion sickness, or vestibular signs)
- Adverse effects (sedation, anticholinergic signs)
Pharmacokinetics
Half-life
Absorption
Very little information is available.
Distribution
Very little information is available.
Metabolism
Metabolized in the liver.
Overdose
Moderate overdosage may result in drowsiness alternating with hyperexcitability.
Massive overdosages may result in:
- Profound CNS depression
- Hallucinations
- Seizures
- Severe anticholinergic effects (tachycardia, urinary retention, etc.)
Treatment:
- Consider gut emptying when patients present soon after ingestion.
- Treatment is symptomatic and supportive.
-
Warning: Avoid respiratory depressant medications.
Available products
Formulations
- Oral Tablets
- Chewable Tablets
- Oral Capsules
Veterinary
- None
Human-labeled
- Meclizine HCl Oral Tablets: 12.5 mg, 25 mg (plain and chewable) & 50 mg (Antivert, Antrizine, Dramamine Less Drowsy Formula, Bonine, generic)
- Meclizine Oral Capsules: 25 mg (Meni-D)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Meclizine products should be stored at room temperature in well-closed containers.
Client information
Timing is key: When using for motion sickness prevention, give the medication 30-60 minutes before travel.
- Sedation: This medication commonly causes drowsiness or sleepiness. Do not be alarmed if your pet sleeps during travel.
- Dry Mouth: It may cause dry mucous membranes. Ensure your pet has access to fresh water.
- Appetite: Cats may occasionally experience a loss of appetite while taking this medication.
- Allergy Testing: Inform your veterinarian if your pet is scheduled for allergy skin testing, as this medication must be stopped 3-7 days prior.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.