Extrapyramidal symptoms associated with selective serotonin reuptake inhibitors - Epidemiology, mechanisms and management

In recent years there has been an increasing number of reports of the devel opment or aggravation of parkinsonism and the development of other movement disorders ('extrapyramidal symptoms') associated with exposure to the sele ctive serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) flu oxetine, paroxetine, sertraline, fluvoxamine and citalopram. The exact prev alence of these complications is unknown since available information comes from literature reviews of case reports or data from the manufacturers or f rom movement disorders units and is therefore subject to reference bins. In addition, many of the patients had previously received or were concurrentl y being treated with other drugs, mainly antipsychotics. Reported movement disorders include parkinsonism, akathisia, tremor, dystonia, tardive dyskin esia, myoclonus, ties and chorea; parkinsonism and akathisia were the most frequent. Pathophysiological mechanisms are not well established, but the most accept ed hypotheses suggest a relationship with interactions between serotonergic and dopaminergic neurotransmitter systems. Anatomical, physiological and p harmacological relationships between these two systems are reviewed in this article. The management of SSRI-induced movement disorders includes avoidance of SSR I use, dose reduction or discontinuation of the offending drug and the same measures that an used for treating antipsychotic-induced movement disorder s.