cyclizine hydrochloride: clinical use

Prescribing considerations

• Review cumulative sedative and anticholinergic burden, alcohol use and fitness to drive.
• Consider reported misuse for euphoric or hallucinatory effects, particularly where use is escalating or unexplained.
• Cyclizine can interfere with allergy testing; liaise with the testing service before any interruption.
• The selected licence covers oral use in adults and children aged six years and over.

Contraindications and cautions

• Hypersensitivity to cyclizine or any listed excipient.
• Acute alcohol intoxication.
• Avoid in porphyria.
• Use cautiously in glaucoma, urinary retention, gastrointestinal obstruction, hepatic disease, phaeochromocytoma, hypertension, epilepsy, possible prostatic hypertrophy, severe heart failure or acute myocardial infarction.

Monitoring

• Assess symptom response and ongoing clinical need.
• Check for sedation, impaired coordination, blurred vision, constipation or urinary retention.
• Investigate jaundice, hepatic symptoms, abnormal movements, seizures or symptoms suggesting blood dyscrasia.
• In severe heart failure or acute myocardial infarction, monitor cardiovascular status if use is considered necessary.

Clinical pharmacology

A piperazine-class H1-receptor antagonist with anticholinergic and antiemetic properties. It reduces labyrinthine sensitivity, may inhibit the medullary emetic centre and increases lower oesophageal sphincter tone. Norcyclizine is a metabolite with relatively little H1 activity.

Formulation and product differences

• The selected product is an oral, uncoated tablet with a central break line and can be divided into equal halves.
• It contains lactose monohydrate and is essentially sodium-free.
• Keep blisters in the outer carton to protect the tablets from light.
• Cyclizine injection products contain cyclizine lactate and have separate product information; the formulation descriptions are not interchangeable.

Tablet

Route: Oral

Strengths: 50 mg