Extrapyramidal adverse drug reactions associated with trimetazidine: a series of 21 cases.

Over the last few years, a number of cases of extrapyramidal disorders associated with trimetazidine (TMZ) use has been reported. Here, we report on a series of 21 cases. All but one of the patients (mean age 74) had been taking TMZ for several years. The indication for prescription of TMZ could not be identified in seven cases. The TMZ-associated adverse drug reactions were typical parkinsonism (akinesia and/or rigidity and/or rest tremor) in 17 cases, gait disorders in three cases (one with orthostatic tremor), and restless leg syndrome in one case. Discontinuation of TMZ led to complete disappearance of the symptoms in 16 cases and a significant reduction in the five other patients. TMZ has the same piperazine core as the dopamine antagonists flunarizine and cinnarizine (both of which have been reported to induce extrapyramidal symptoms). Hence, striatal D2 receptor blockade could result in the onset or the worsening of extrapyramidal disorders. Even though this adverse drug reaction is now listed in TMZ's Summary of Product Characteristics (because of the initial reports), the risk remains poorly known by clinicians. There is a need to raise awareness of this phenomenon and to reassess TMZ 's risk-benefit ration, especially in the elderly.