cinnarizine + dimenhydrinate: clinical use

Prescribing considerations

• Confirm that symptoms represent vertigo requiring symptomatic treatment and investigate concerning or persistent causes.
• Establish renal and hepatic function before prescribing; avoid use in severe impairment.
• Assess sedation, falls risk, anticholinergic burden, hypotension, Parkinsonism and interacting medicines.
• Warn about impaired driving, alcohol and masking of aminoglycoside ototoxicity or allergy skin-test responses.

Contraindications and cautions

• Hypersensitivity to cinnarizine, dimenhydrinate, diphenhydramine, structurally related antihistamines or an excipient
• Severe renal impairment
• Severe hepatic impairment
• Angle-closure glaucoma
• Convulsions or suspected raised intracranial pressure
• Alcohol abuse
• Urinary retention caused by urethroprostatic disease

Monitoring

• Monitor for sedation, anticholinergic adverse effects and worsening Parkinsonian or extrapyramidal symptoms.
• Reassess renal or hepatic suitability if clinical status changes.
• Investigate jaundice, infection with systemic deterioration, unexplained bruising or weakness; consider liver tests or a blood count as clinically indicated.

Clinical pharmacology

Dimenhydrinate acts predominantly on central vestibular pathways through antihistamine, antimuscarinic and central depressant effects. Cinnarizine inhibits calcium influx into vestibular sensory cells and acts mainly on the peripheral vestibular system; both undergo extensive hepatic metabolism.

Formulation and product differences

• The selected product is an uncoated tablet intended to be swallowed whole and supplied in blister packs; no alternative selected formulation is available for comparison.
• It is considered essentially sodium-free.

Tablet

Route: Oral

Strengths: 20 mg + 40 mg