A fixed-dose combination (FDC) of a selective calcium channel blocker (Cinnarizine) and a first-generation ethanolamine antihistamine (Dimenhydrinate). It is primarily used for the prophylaxis and treatment of vestibular vertigo and motion sickness. Cinnarizine acts by improving labyrinthine and cerebral blood flow and reducing vestibular excitability, while Dimenhydrinate provides central antiemetic and sedative effects via H1-antagonism and anticholinergic action. This combination offers a synergistic effect for managing vertigo and associated nausea/vomiting, making it a widely prescribed formulation in India for conditions like Ménière's disease and motion sickness.
Adult: One tablet (Cinnarizine 20mg + Dimenhydrinate 40mg) three times daily. For motion sickness prophylaxis: One tablet 30 minutes before travel, may repeat every 4-6 hours as needed (max 3 tablets in 24 hours).
Note: Administer orally with or without food. Taking with food may reduce gastric irritation. Tablet should be swallowed whole with a glass of water. For motion sickness, take at least 30 minutes before exposure to motion.
The combination exerts a dual mechanism. Cinnarizine is a selective calcium channel blocker that inhibits calcium influx into vascular smooth muscle cells and labyrinthine arterial cells, leading to vasodilation. This improves microcirculation in the inner ear (labyrinth) and brain. It also reduces the excitability of vestibular sensory cells and inhibits vestibular nuclei. Dimenhydrinate is a salt of diphenhydramine (an H1-antagonist) and 8-chlorotheophylline (a mild CNS stimulant). Its primary action is antagonism of histamine H1 receptors in the vomiting center and the vestibular pathway. It also possesses significant antimuscarinic (anticholinergic) activity, which further depresses vestibular stimulation and labyrinthine excitability. The combination provides synergistic control of vertigo, nausea, and vomiting.
Pregnancy: Category B (US FDA) for Dimenhydrinate; Cinnarizine data is limited. Not recommended during pregnancy unless clearly needed. Avoid in first trimester. Use only if potential benefit justifies potential risk to the fetus.
Driving: STRONGLY ADVISED AGAINST. The combination causes significant drowsiness, dizziness, and blurred vision, impairing the ability to drive or operate machinery. Patients should not engage in these activities for at least 8-12 hours after a dose.
| CNS Depressants (Alcohol, Benzodiazepines, Opioids, Barbiturates) | Additive CNS depression, increased sedation, impaired psychomotor performance. | Major |
| Anticholinergic Drugs (Atropine, TCAs, Antipsychotics like clozapine) | Additive anticholinergic effects (dry mouth, constipation, urinary retention, blurred vision, confusion). | Major |
| MAO Inhibitors (Phenelzine, Tranylcypromine) | Increased anticholinergic and CNS depressant effects. Risk of hypertensive crisis. | Major |
| Other Antihypertensives | Potentiation of hypotensive effect. | Moderate |
| CYP2D6 Inhibitors (Fluoxetine, Paroxetine, Quinidine) | Increased plasma levels of both drugs, leading to enhanced effects and toxicity. | Moderate |
| Warfarin | Potential increased anticoagulant effect (theoretical). Monitor INR. | Moderate |
Same composition (Cinnarizine (20mg) + Dimenhydrinate (40mg)), different brands: