Objective: To study the adverse effects of trimetazidine on motor functions.
Design: A retrospective study was carried out using electronic records to identify all patients seen between January 1990 and August 2003.
Setting: A neurological out-patient clinic.
Participants: Of the 10 258 patients who attended the clinic, 130 received trimetazidine. Treatment with this drug was discontinued in 128 patients. Of the 130 patients treated with trimetazidine, 29 also had other drugs capable of inducing parkinsonism withdrawn from their treatment.
Main outcome measures: Identification of an improvement in motor function after drug withdrawal.
Results: In 56 of the 130 patients who were treated with trimetazidine (43%), an adverse effect on motor function was detected that had been induced or aggravated by one of the withdrawn drugs. Indeed, drug-induced parkinsonism was detected in 20 of these patients. Of these, ten were being treated with trimetazidine only, while the remaining ten were simultaneously receiving other drugs potentially capable of inducing parkinsonism. Treatment with trimetazidine worsened previously diagnosed Parkinson's disease in 12 patients, and gait disorders coupled with disequilibrium was observed in 15 patients. Trimetazidine induced tremor in nine patients.
Conclusion: Trimetazidine can induce parkinsonism, gait disorder and tremor. These adverse effects have not been previously described for this drug.