Trihexyphenidyl abuse in schizophrenic patient: a case report

Abstract

Trihexyphenidyl is a synthetic anticholinergic used in psychiatric patient for the relief of neuroleptic-induced extrapyramidal symptoms. It has been reported to have mood elevating, euphorigenic and socially-stimulating effects. The case presented is of anti-cholinergic abuse by a chronic schizophrenic who abused trihexyphenidyl, up to 200 mg per day, to achieve an euphoric effect. The drug was partly prescribed in psychiatric clinics, but mostly bought in the drugstore. The discontinuance of trihexyphenidyl produced anxiety, which was relieved by anxiolytics. The patient also feigned extrapyramidal symptoms to get anticholinergic injections during drug abstinence. A high dose of trihexyphenidyl may precipitate anticholinergic toxic psychosis and interfere with the therapeutic effects of antipsychotics by impeding their absorption. Given a large number of patients receiving this medication, clinicians should be alert when prescribing this drug, especially for patients who have abuse potential. As this agent has never been under public surveillance and is available in local pharmacies, the health authorities should be concerned with its abuse potential.