Oxomemazine

Products

Oxomemazine is commercially available as syrups (Toplexil N syrup). It has been approved in many countries since 1966. In France, several drugs containing oxomemazine are on the market.

Structure and properties

Oxomemazine (C₁₈H₂₂N₂S, M_r = 298.4 g/mol) is a phenothiazine closely related structurally to the neuroleptic promethazine. It exists as a white, crystalline powder with a bitter taste that is practically insoluble in water.

Effects

Oxomemazine (ATC R06AD08) has antihistamine, antiallergic, anticholinergic, and depressant/ sedative properties.

Indications

For the treatment of dry, troublesome cough (especially of allergic origin) and irritable cough.

Dosage

According to the professional information. The syrup is taken two to three times daily.

Abuse

Oxomemazine may be abused as an intoxicant because of its depressant properties.

Contraindications

• Hypersensitivity
• Children under 2 years
• Respiratory failure
• Agranulocytosis
• History of urethral or prostate-related risk of urinary retention.
• Narrow-angle glaucoma
• Concomitant administration of MAO inhibitors or amisulpride (risk for cardiac arrhythmias).
• Attenuation of the CNS of any cause

Full precautions can be found in the drug label.

Interactions

Drug-drug interactions are possible with central depressant drugs, alcohol, anticholinergic agents, amisulpride, and MAO inhibitors.

Adverse effects

Possible adverse effects include fatigue, drowsiness, anticholinergic side effects (dry mouth, central disturbances, confusion, hallucinations, excitability, urinary retention, cardiac arrhythmias, low blood pressure), skin rashes, and hypersensitivity reactions.