RT Journal Article SR Electronic T1 Olanzapine in the treatment of hallucinosis in idiopathic parkinson’s disease: a cautionary note JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 774 OP 777 DO 10.1136/jnnp.65.5.774 VO 65 IS 5 A1 Jacqueline M Graham A1 Jon D Sussman A1 Kay S Ford A1 Harvey J Sagar YR 1998 UL http://jnnp.bmj.com/content/65/5/774.abstract AB BACKGROUND Hallucinosis is a dopaminergic dose limiting complication of the treatment of idiopathic Parkinson’s disease. Typical neuroleptic medications cannot be used for suppressing hallucinosis because the extrapyramidal side effects worsen parkinsonian motor control. Olanzapine is a novel atypical antipsychotic drug with few reported extrapyramidal side effects which may be more suitable for controlling hallucinosis in these patients. METHODS Olanzapine was given to five patients with idiopathic Parkinson’s disease and the dosage was titrated until a clinically meaningful reduction in hallucinosis was achieved. The commercially available 5 mg, 7.5 mg and 10 mg tablets were used. RESULTS After an initial 9 days of treatment, hallucinosis frequency was significantly reduced, an effect which was maintained with continued treatment. However, during this early phase of treatment, parkinsonian motor disability increased, which resulted in two of the patients discontinuing medication. CONCLUSIONS Olanzapine is effective in the suppression of hallucinosis in patients with idiopathic Parkinson’s disease but the currently available dose increments may result in an unacceptable exacerbation of motor disability.