cinnarizine: clinical use

Prescribing considerations

• Assess sedation risk, driving and concurrent alcohol or CNS-depressant use.
• In Parkinson’s disease, use only when anticipated benefit outweighs the risk of aggravating symptoms.
• Avoid use in porphyria and use cautiously in hepatic or renal impairment because specific studies are lacking.
• Consider lactose and sucrose content in people with relevant hereditary carbohydrate-intolerance disorders.

Contraindications and cautions

• Hypersensitivity to cinnarizine or any product excipient.
• Relevant rare hereditary fructose or galactose intolerance, lactase deficiency, glucose-galactose malabsorption or sucrase-isomaltase insufficiency for the selected formulation.

Monitoring

• Review troublesome somnolence, gastrointestinal symptoms and weight gain.
• Assess promptly for parkinsonism, tremor, dyskinesia or muscle rigidity, particularly in older people or with prolonged exposure.
• Investigate symptoms suggesting cholestatic jaundice or a lupus-like photosensitive rash.

Clinical pharmacology

Cinnarizine antagonises histamine-mediated smooth-muscle contraction, inhibits calcium influx into depolarised vascular smooth-muscle cells and suppresses vestibular responses. Oral absorption is relatively slow; it is highly protein-bound and extensively metabolised, mainly through CYP2D6, with substantial variability between individuals.

Formulation and product differences

• The selected product is a white, circular, biconvex oral tablet marked S/15.
• The selected formulation contains lactose monohydrate and sucrose.

Tablet

Route: Oral

Strengths: 15 mg