Study of penfluridol and chlorpromazine in the treatment of chronic schizophrenia. Loxapine versus chlorpromazine in paranoid schizophrenia: a double-blind study. Comparison of pimozide and chlorpromazine in acute schizophrenia. Propranolol as an adjunct to the treatment of schizophrenia.
This study presents data on the use of penfluridol, a once-a-week orally administered, antipsychotic agent, in the treatment of chronic schizophrenic patients. Fifty-nine patients participated in the initial dose titration segment during which doses of penfluridol were adjusted weekly until the patients' condition became stabilized. The starting dose did not exceed 60 mg per week, and the maximum weekly dose did not exceed 140 mg. Forty-one of these patients continued on to participate in a double-blind comparison of penfluridol with chlorpromazine. Maximum doses did not exceed 140 mg per dose per week for penfluridol and 7350 mg per week for chlorpromazine in the double-blind segment. Patients were abruptly switched from their previous neuroleptic medication to penfluridol without loss of control. Side effects, mainly extrapyramidal in nature, were readily alleviated with benztropine mesylate. Penfluridol, administered orally once a week, appeared to be well tolerated; it was comparable to daily chlorpromazine in treating and maintaining schizophrenic patients. Newly admitted paranoid schizophrenic patients (N = 68) were treated with either loxapine or chlorpromazine for up to 4 weeks. Mean maximum dosages were 84 mg/day of loxapine and 820 mg/day of chlorpromazine. Loxapine showed efficacy superior to that of chlorpromazine, confirming earlier retrospective findings. Adverse reactions were also less troublesome with loxapine. A four week double-blind study comparing pimozide and chlorpromazine was designed to test the hypothesis that pimozide, a powerful dopamine receptor blocker, is more effective in the treatment of acute schizophrenia than chlorpromazine. Twenty patients, 13 males and 7 females ranging in age from 21 to 53 years (mean age 33 years) admitted to ST. Mary's Hospital with acute schizophrenia were placed on the study. They were treated on an individual titrated dosage of either chlorpromazine 300 mg to 2100 mg, or pimozide 10 to 70 mg. The results revealed that on the Brief Psychiatric Rating Scale, the chlorpromazine group significantly improved after one week, whereas the pimozide group showed no statistical improvement until the third week. By the end of the study no significant differences were apparent between the two groups. In the Clinical Global Impression Scale, a significant difference between the two groups was found at week 4 showing a greater improvement in the chlorpromazine group. In terms of adverse reactions, the chlorpromazine group had significantly fewer extrapyramidal symptoms than the pimozide group (Simpson and Angus Scale) and in addition 15 adverse reactions were noted for the pimozide group as compared with 8 for the chlorpromazine group. This study shows that chlorpromazine has an earlier onset of action than pimozide in the acute schizophrenic patient despite the fact that it has a weaker effect on the dopamine receptor than has pimozide. In view of this finding, the dopamine theory of schizophrenia should be critically re-examined. Propranolol contributed usefully to the practical management of patients with chronic schizophrenia whose florid symptoms had not remitted with major tranquillisers. 14 patients who had received an average equivalent of 954 mg per day of chlorpromazine for 10 years were given, in addition, either propranolol or a placebo for 12 weeks. Both groups had improved by the twelfth week, but the propranolol group had improved significantly more.
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.