Clinical effects and drug concentrations in plasma and cerebrospinal fluid in psychotic patients treated with fixed doses of chlorpromazine. Chlorpromazine in chronic schizophrenia. The effect of age and hospitalization on behavioral dose-response relationships. Alpha-methyldopa-chlorpromazine combination in schizophrenic patients. Prien RF, Cole JO: High dose chlorpromazine therapy in chronic schizophrenia. Report of National Institute of Mental Health--psychopharmacology research branch collaborative study group.
The clinical effects of chlorpromazine (CPZ) administered in accordance with a double-blind design in one of three doses (200, 400 or 600 mg) were examined in 44 psychotic patients. The relationships between the effects and the CPZ concentrations in plasma and cerebrospinal fluid (CSF) were analyzed. The antipsychotic and side effects were rated according to the CPRS and the Simpson and Angus scale. CPZ concentrations were measured by a mass fragmentographic method. Treatment with CPZ resulted in a significant reduction of morbidity scores, without any clear dose relation. The final outcome was more favourable in women than in men. Extrapyramidal side effects but not somnolence were positively dose related. The antipsychotic effects tended to be positively related to the dose of CPZ in mg/kg as well as the CPZ concentrations in plasma and CSF. The greatest number of significant correlations between the CPZ concentration in CSF and the morbidity scores were seen after 2 weeks of treatment. The results indicated marked clinical improvement with CPZ concentrations above 1 ng/ml in CSF and 40 ng/ml in plasma. After 4 weeks of treatment the correlations between the CPZ concentrations and the clinical improvement were still positive but the coefficients were lower than at 2 weeks and only occasionaly significant. Extrapyramidal symptoms were significantly related to the CPZ concentrations in plasma and CSF. Somnolence was significantly related to the CPZ concentrations in CSF. nan In a double-blind, controlled clinical study, lasting 8 weeks, 55 hospitalized schizophrenic patients were randomly assigned to one of the five drug treatments: 600 mg chlorpromazine/day, 300 mg chlorpromazine/day, 300 mg chlorpromazine--250 mg alpha-methyldopa/day, 300 mg chlorpromazine--500 mg alpha-methyldopa/day, 300 mg chlorpromazine--750 mg alpha-methyldopa/day. The results showed that all five treatments were significantly effective in treating schizophrenic behavior. The dose-response relationship for the different doses of alpha-methyldopa in combination with chlorpromazine, suggested an optimal response to 300 mg chlorpromazine--500 mg alpha-methyldopa. nan
The average dose of chlorpromazine given to people with schizophrenia has declined across time, but this has come about by long - and sometimes hard - experience rather than from direction from high-grade trial-based evidence. This progression towards gentler levels of dosing has taken six decades. We hope that, for modern compounds, data from relevant high-grade evaluative studies will be much more swiftly available to guide informed practice.