[A case of choreoathetoid movements induced by anticholinergic drugs, trihexyphenidyl HCl and dosulepin HCl]

Abstract

We report a 72-year-old woman who showed marked orolingual dyskinesia and choreoathetoid movements of the neck, with rolling and nodding of the head. She had been treated for postural tremor and other complaints with multiple drugs, including trihexyphenidyl HCl (THP) 6 mg/day for about two years. Moreover, two months before admission to our hospital, a doctor added tricyclic antidepressant, dosulepin HCl (DL) because of her state of anxiety. Two weeks following DL administration, the persistent dyskinesia described above appeared. Suspecting the dyskinesia to be induced by anticholinergics, we withdrew THP, which decreased the intensity of the dyskinesia. Then, when DL was ceased the dyskinesia almost completely disappeared, slightly recurring only during calculating, when excited or writing. In order to confirm that anticholinergics were the cause of the dyskinesia, we administered THP 6 mg/day again. In a few days the same dyskinesia reappeared, disappearing following THP withdrawal. In this case the overlap of anticholinergics might have resulted in the dyskinesia, because both THP and DL have anticholinergic effects. It should be stressed that inappropriate administration of anticholinergics could cause severe dyskinesia in the elderly.