N-Cinarizina (Cinnarizine)

Cinnarizine acts on the vestibular system and histamine pathways to alleviate balance‑related disorders.

• Vertigo: reduces vestibular hyperexcitability and helps control dizziness.
• Motion sickness: diminishes the sensation of nausea and vomiting caused by movement.
• Nausea: alleviates general nausea associated with inner‑ear disturbances.
• Meniere's disease: improves hearing stability and reduces episodic vertigo attacks.

• Cinnarizine antagonizes H1 histamine receptors, decreasing histamine‑mediated vestibular stimulation, while simultaneously blocking voltage‑dependent calcium channels in inner‑ear vessels, which improves microcirculation and reduces neuronal excitability responsible for vertigo and related symptoms.

Cinnarizine may cause a range of adverse reactions, most of which are mild and reversible.

Common Side Effects

• Drowsiness: feeling unusually sleepy or fatigued.
• Dry mouth: reduced salivation leading to a dry oral cavity.
• Gastrointestinal discomfort: mild nausea or abdominal upset.
• Weight gain: modest increase in body weight over prolonged use.
• Visual disturbances: blurred vision or difficulty focusing.
• Skin rash: mild erythema or itching.

Serious or Rare Side Effects

• Extrapyramidal symptoms: involuntary muscle movements or tremor.
• Severe allergic reaction: swelling, hives, or difficulty breathing.
• Hepatotoxicity: signs of liver dysfunction such as jaundice.
• Hematologic changes: unexplained bruising or low blood counts.
• Cardiac arrhythmia: irregular heartbeat in susceptible individuals.

Before initiating therapy with Cinnarizine, consider the following safety measures.

• Assess liver function: monitor hepatic enzymes in patients with liver disease.
• Evaluate renal status: adjust use in severe renal impairment.
• Review CNS depressants: avoid concurrent use with other sedatives to limit excessive drowsiness.
• Caution in the elderly: start with the lowest effective dose due to increased sensitivity.
• Avoid in patients with known hypersensitivity to cinnarizine or similar antihistamines.
• Store at ambient temperature: keep below 25 °C, retain in original packaging, protect from moisture.

Cinnarizine can interact with several drug classes, altering efficacy or safety.

Major Interactions (Avoid)

• Anticholinergic agents: may amplify dry mouth and constipation.
• Other antihistamines: increase risk of sedation and central nervous system depression.

Moderate Interactions (Monitor Closely)

• CYP3A4 inhibitors (e.g., ketoconazole): may raise cinnarizine plasma levels.
• CNS depressants (e.g., benzodiazepines): enhance drowsiness.
• Alcohol: additive sedative effect.
• MAO inhibitors: potential for exaggerated hypotensive response.