[Exogenous psychoses in Parkinson syndrome. Frequency and causal conditions]

Clinical risk-benefit assessment of dopamine agonists

Dopamine agonists (DAs) have proven efficacy as monotherapy in early Parkinson's disease (PD) for preventing motor complications such as dyskinesia and as adjunct therapy as the disease progresses. Further, it is increasingly evident that at least some DAs may provide additional benefits, such as reduction in depressive symptoms and treatment of refractory tremor. Different side-effect profiles have been associated with levodopa and ergot or non-ergot DA treatment, such as sudden onset of sleep, reduced impulse control, hallucination, and cardiovascular fibrosis. This paper discusses the evidence for specific associations between particular treatments and side effects as well as the clinical implications for patient care. Ultimately, the choice depends on the risk-benefit assessment as it applies to the individual patient's clinical profile and the physician's preference.

Therapeutic effect of clozapine in psychotic decompensation in idiopathic Parkinson's disease

Seven patients with idiopathic Parkinson's disease, aged 62 to 76 years, average duration of the disease approximately eleven years, suffering from severe hallucinosis and paranoid delusions of different degree, in whom conventional therapeutic strategies (administration of benzodiazepines and mild neuroleptics) had no antipsychotic effect, received clozapine, a non-classical highly potent neuroleptic, while blood count was strictly monitored. Paranoid ideas disappeared in all seven patients after a maximum of four days administration of 25-125 mg/day. No deterioration of parkinsonian symptoms, quantified according to UPDRS was seen. Given the protection of clozapine, we could increase the L-dopa dose in two cases, thereby improving the patients' motor function. Blood count showed no abnormalities in any of the patients during an average observation period of seventeen months. Our results support the assumption that clozapine has a potent antipsychotic effect in the treatment of psychotic decompensation in advanced Parkinson's disease in carefully selected patients. We saw no negative influence of the neuroleptic on extrapyramidal symptoms.

Psychiatric admissions due to adverse drug reactions

This is a report of the findings of a 6-year study of hospitalizations caused by adverse psychiatric reactions to prescribed medications. Of 15,800 consecutive psychiatric admissions to two university hospitals, 112 (0.7%) were caused by adverse reactions to medications. In 67% of cases these admissions were due to extrapyramidal symptoms such as parkinsonism and/or akathisia, and coexisting neuroleptic-related depression. In 25% the admitting diagnosis was drug-induced delirium or psychosis; one third of these patients suffered from Parkinson's disease and had been treated with a combination of two or more antiparkinsonian agents. Older age, polydrug therapy, and the parenteral administration of neuroleptics at high dosages were important risk factors for severe adverse drug reactions leading to hospitalization.

Treatment of drug-induced exogenous psychosis in parkinsonism with clozapine and fluperlapine

A total of 13 patients with drug-induced psychosis in Parkinson's disease were treated with two non-classical neuroleptics-clozapine and fluperlapine. Patients mainly complained about severe hallucinatory symptoms and different degrees of paranoid delusions. Complete relief was observed in 8 patients, moderate improvement in 3 and no effects in 2. Parkinsonian disability did not increase under neuroleptic medication with clozapine and fluperlapine, but could be ameliorated by additional L-dopa or bromocriptine medication. The non-classical neuroleptics employed are dopamine D2 blocking agents with a preferential binding to mesolimbic, mesocortical and hippocampal D2 receptors and no substantial binding to striatal dopamine receptors. Restricted use of these two neuroleptics is necessitated because of the danger of agranulocytosis.