Benztropine - Antiparkinsonian Drug

Benztropine

Benztropine mesylate (or benzatropine methanesulfonate) is a synthetic tertiary amine antimuscarinic antiparkinsonian drug possessing anticholinergic, antihistaminic, and local anaesthetic effects.

It can be administered orally, intramuscularly, or intrave- nously. Adverse effects include skin rash, dry mouth, mydriasis, diplopia, nausea, and tachycardia. Risk of anticholinergic side effects is greatly increased when administered with other anticholinergic drugs, and may result in paralytic ileus or hyperthermia which can be fatal.

Overdose produces weakness, confusion, depression, vomiting, urinary retention, constipation, paralytic ileus, hyperthermia, heat stroke, and hallucinations. ECG changes include sinus tachycardia without QRS or QTc prolongation. Acute psychosis characterised by bizarre behaviour has been reported. Death can occur.

Serum benztropine levels over 100 ng/ml are associated with serious toxicity.

Treatment involves ECG monitoring, gastric lavage, and activated charcoal. Physostigmine can be considered in the pres-ence of serious toxicity. Supportive measures include catheteri-sation of bladder, treatment of hyperthermia, hypertension, etc.