A 4-Week, Double-Blind Comparison of Olanzapine with Haloperidol in the Treatment of Amphetamine Psychosis
Thawatchai Leelahanaj MD, MSc*, Ronnachai Kongsakon MD, LLB, MSc**, Pongsatorn Netrakom MD*
Affiliation : * Department of Psychiatry and Neurology, Phramongkutklao Hospital ** Department of Psychiatry, Ramathibodi Hospital
Objective : To compare the efficacy and tolerability of olanzapines and haloperidol in treating patients
with amphetamine psychosis.
Materials and Methods : Fifty-eight patients experiencing episode of amphetamine psychosis were
randomly assigned to olanzapine (N=29) or haloperidol (N=29) in 1:1 (olanzapine: haloperidol) ratio.
All patients started with 5-10 mg/day of the study drug; after each 7-day period, the study drug could be
adjusted in 5-mg increments or decrements within the allowed dose range of 5-20 mg/day during the
4-week double-blind period.
Results : Clinical response was seen in both treatment groups since the first week. Ninety three percent of
the olanzapine patients (N=27 of 29) and 79.3% of the haloperidol patients (N=23 of 27) were clinically
improved at endpoint. These differences were not statistically significant (p=0.25). The Simpson-Angus
total score change from baseline to endpoint reflected no extrapyramidal symptoms among the
olanzapine-treated patients (median=0.0, range=0.0). In contrast, worsening occurred among the
haloperidol-treated patients (median=0.2, range=0.0-3.1). The differences of mean change in Simpson
Angus Scale significantly favored olanzapine (p<0.01). Change to endpoint on the Barnes Akathisia
Scale showed that olanzapine-treated patientsû scores were close to the baseline (median=0.0, range=-1.0-0.0),
whereas haloperidol-treated patientsû scores worsened from the baseline (median=0.0, range=-1.0-3.0).
This difference was statistically significant (p=0.02).
Conclusion : Both olanzapine and haloperidol were efficacious in the treatment of patients with amphetamine
psychosis. Olanzapine was superior to conventional neuroleptic haloperidol in treatment safety with
lower frequency and severity of extrapyramidal symptoms.
Keywords : Amphetamine psychosis, Treatment, Olanzapine, Haloperidol, Efficacy, Tolerability
