Olanzapine can worsen parkinsonism

Psychiatric complications of levodopa and dopamine agonists often limit the therapy of Parkinson's disease (PD).1 These side effects may reflect over-stimulation of mesolimbic dopamine receptors.1 Clozapine, which binds preferentially to D4 receptors,2 is a useful treatment for drug-induced psychosis in PD.3 Olanzapine, another new neuroleptic, has been recently proposed as an effective and safe treatment for dopaminomimetic psychosis in PD.4 We describe two PD patients, previously treated with clozapine, who experienced worsening of their parkinsonism after starting olanzapine. Case reports. Patient 1. A 67-year-old woman with PD since 1984 developed cenesthetic hallucinations (defined as somatic hallucinations or false sensations of things occurring in or to the body, visceral in origin) in September 1995 when she was on therapy with controlled-release carbidopa/levodopa 450/1,800 mg/d and pergolide 3.5 mg/d. This case was recently reported.5 In January 1997, cenesthetic hallucinations were well controlled with clozapine 200 mg/d. At that …