Olanzapine induced tardive dystonia

Advent of atypical antipsychotics was thought to be a major advancement in the psychopharmacology for schizophrenia. It was thought that these drugs would have low propensity to induce extrapyramidal symptoms including tardive movements. Olanzapine is a thienobenzodiazepine derivative, second generation (atypical) antipsychotic agent. Compared to typical antipsychotics, it has a greater affinity for serotonin 5-HT2A than dopamine D2 receptors, with preferential action at mesolimbic than nigrostriatal dopaminergic pathways. However, only few reports of olanzapine induced tardive dystonia (TD) are available in the literature. We wish to report another case of TD, in a male patient with schizophrenia, which developed after 15 months of treatment with olanzapine.