Benzatropine 86-13-5

Indications

Benzatropine is used in patients to reduce the side effects of antipsychotic treatment, such as parkinsonism and akathisia. Benztropine is also a second-line drug for the treatment of Parkinson's disease. It improves tremor but not rigidity. Benztropine is also sometimes used for the treatment of dystonia, a rare disorder that causes abnormal muscle contraction, resulting in twisting postures of limbs, trunk, or face.

Side effects

These are principally anticholinergic:

• Dry mouth
• Blurred vision
• Cognitive changes
• Constipation
• Urinary retention
• Tachycardia
• Anorexia
• Psychosis (an overdose situation)

While some studies suggest that use of anticholinergics increases the risk of tardive dyskinesia (a long-term side effect of antipsychotics), other studies have found no association between anticholinergic exposure and risk of developing tardive dyskinesia.

Pharmacology

Benztropine is a centrally acting anticholinergic/antihistamine agent resulting from the combination of the tropine portion of the atropine molecule and the benzohydryl portion of diphenhydramine. Animal studies have indicated that anticholinergic activity of benztropine is approximately one-half that of atropine, while its antihistamine activity approaches that of mepyramine. Its anticholinergic effects have been established as therapeutically significant in the management of parkinsonism. Benztropine antagonises the effect of acetylcholine, decreasing the imbalance between the neurotransmitters acetylcholine and dopamine, which may improve the symptoms of early Parkinson's disease. Benztropine also acts as a dopamine reuptake inhibitor, which may further substantiate its efficacy in treating Parkinson's.