What is Cinnarizine?

Cinnarizine is a piperazine derivative with antihistamine and calcium channel blocking properties. It is widely used to prevent and treat symptoms of motion sickness, vertigo, and certain vestibular disorders. The drug is known for improving labyrinthine blood flow and reducing vestibular stimulation.

Mechanism of Action

Cinnarizine exerts its anti-vertigo effects by blocking histamine H1 receptors and inhibiting calcium influx into cells — particularly in the vestibular system and vascular smooth muscle. This dual action helps suppress nystagmus, nausea, and dizziness.

Indications and Approved Uses

• Motion sickness – prevention and treatment of nausea and vomiting during travel.
• Vertigo – symptomatic relief of peripheral (vestibular) vertigo, including Meniere’s disease and labyrinthitis.
• Balance disorders – off-label for chronic imbalance in elderly patients.
• Migraine-associated vertigo – sometimes used when other agents (betahistine, prochlorperazine) fail.

Dosage and Administration

Typical adult dose: 25 mg to 75 mg two or three times daily, depending on the condition. For motion sickness, 15–30 mg taken one hour before travel, then repeated every 8 hours if needed. Use the lowest effective dose in elderly patients due to risk of extrapyramidal symptoms.

Available as tablets, capsules, and in some countries as a suspension. Always follow the prescribing physician’s guidance.

Side Effects and Precautions

Common side effects include drowsiness, dry mouth, headache, and mild gastrointestinal disturbances. Less common but serious effects: extrapyramidal symptoms (especially in older adults), QT prolongation (rare), hypotension, and liver enzyme elevation. The drug can cause drowsiness — avoid driving or operating machinery until you know how it affects you.

Contraindications: hypersensitivity to cinnarizine or any piperazine derivative, Parkinson’s disease, severe hypotension, and concurrent use with alcohol or CNS depressants. Caution in pregnancy and lactation — limited safety data exist; use only if potential benefit outweighs risk.

Drug Interactions

Enhanced sedative effect with alcohol, benzodiazepines, opioids, antipsychotics, and other CNS depressants. May antagonize the effect of antihypertensives (via hypotensive action). Avoid combination with other anticholinergics due to additive dry mouth and constipation. CYP2D6 inhibitors (e.g., fluoxetine, paroxetine) can increase cinnarizine levels — dose adjustment may be needed.

Special Populations

• Elderly: Higher risk of confusion, falls, and extrapyramidal side effects. Start at low doses and monitor closely.
• Children: Limited evidence; generally not recommended under 5 years of age unless under specialist care.
• Pregnancy / Lactation: Insufficient human data; avoid unless clearly necessary. Small amounts may pass into breast milk — caution if breastfeeding.

Comparative Role: Cinnarizine vs Alternatives

Compared to betahistine, cinnarizine is more effective for acute vertigo and motion sickness but has stronger sedation. For Meniere’s disease, betahistine is often first-line, while cinnarizine may be added for breakthrough symptoms. Prochlorperazine is another antiemetic option but carries higher risk of extrapyramidal reactions. Cinnarizine’s calcium channel blocking property may also improve migraine-associated vertigo but evidence is mixed.