Biperiden Hydrochloride

What it is and how it works

Biperiden is a centrally acting muscarinic receptor antagonist that reduces the relative cholinergic excess in the striatum resulting from dopamine deficiency or dopamine-receptor blockade.

Indications

Parkinsonism, particularly for tremor; drug-induced extrapyramidal symptoms (excluding tardive dyskinesia), including acute dystonic reactions caused by antipsychotics.

Dosage and administration (summary)

Oral: initially 1 mg twice daily, increased gradually to a usual maintenance of 3–12 mg daily in divided doses. Acute drug-induced reactions: 2.5–5 mg by intramuscular or slow intravenous injection, repeated if necessary (maximum about 20 mg in 24 hours).

Contraindications

Angle-closure glaucoma, gastrointestinal obstruction, megacolon, untreated urinary retention, and hypersensitivity to biperiden.

Warnings and precautions

Antimuscarinic effects include dry mouth, blurred vision, constipation, urinary retention and tachycardia; confusion, memory impairment and hallucinations are more likely in the elderly. It does not improve and may worsen tardive dyskinesia; potential for misuse due to euphoriant effects. Avoid abrupt withdrawal; may impair ability to drive.

Pregnancy

Use in pregnancy only if clearly necessary.

Storage and supply

Store below 25 °C, protected from light.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.