Optimal haloperidol dosage in first-episode psychosis.
OBJECTIVE
To determine optimal doses of haloperidol for the treatment of a first episode of psychosis.


METHODS
A 4-week prospective controlled clinical trial with "optimal dose" defined as the dose at which either of the following occurs: 1) significant improvement, defined as a 15% or greater decrease in scores on the Positive And Negative Syndrome Scale (PANSS), or 2) the onset of extrapyramidal symptoms. Beginning with 2 mg daily, haloperidol was increased weekly to 5 mg, 10 mg, and finally 20 mg daily until either 1) or 2) occurred.


RESULTS
Optimal doses for the 36 subjects were 2 mg daily for 15 subjects, 5 mg daily for 11, 10 mg daily for 7, and 20 mg daily for 3. On average, subjects whose optimal dose was 2 mg daily showed the greatest improvement. Among the 27 subjects evidencing clinical response to treatment, 20 had plasma haloperidol levels below 5 ng/ml.


CONCLUSIONS
Many people suffering a first psychotic episode respond to haloperidol doses well below levels in common use.
Zhang-Wong
J
J
Centre for Addiction and Mental Health, Clarke Division, Toronto, Ontario. Joey.Wong@utoronto.ca
Zipursky
R B
RB
Beiser
M
M
Bean
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D000328:Adult; D000704:Analysis of Variance; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004409:Dyskinesia, Drug-Induced / Q000209:etiology; D017050:Episode of Care; D005260:Female; D006220:Haloperidol / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011618:Psychotic Disorders / Q000188:drug therapy*; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D006220:Haloperidol