Four RCTs (n=1,054) were included.
All of the included studies were double-blind, and the results from 3 of the 4 trials were based on last observation carried forward.
One RCT (270 patients with schizophrenia) found that the response rates for the PANSS-EC at 2 hours demonstrated that all doses of olanzapine and haloperidol were superior to placebo in reducing agitation, and that a greater proportion of participants in the olanzapine and haloperidol groups achieved an improved clinical response. No statistically significant differences in clinical improvement between olanzapine and haloperidol were reported. The RCT also found that olanzapine reduced parkinsonism (0.6% versus 16.7%), akathisia (1.1% versus 7.9%) and acute dystonic reaction (0% versus 5%)in comparison with haloperidol, but increased hypotension (3.8% versus 0%).
One RCT (311 patients with schizophrenia) found significantly greater mean improvements on the PANSS-EC, ACES and ABS at 2 and 24 hours in the olanzapine 10 mg and haloperidol 7.5 mg groups compared with placebo; no statistically significant differences between olanzapine and haloperidol were found. The study also reported that olanzapine significantly reduced dystonic reactions compared with haloperidol (90% versus 7%, P=0.03).
One RCT (201 patients with bipolar disorder) found greater mean improvement on the PANSS-EC, ABS and ACES in the olanzapine 10 mg group at 2 hours compared with lorazepam 2 mg and placebo (80% versus 34% and 44%, P=0.045 and P<0.001, respectively). The study also found that lorazepam increased adverse effects compared with olanzapine and placebo (51% versus 34% and 26%).
One RCT (272 patients with dementia) found improved response rates on the PANSS-EC, CMAI and ACES for olanzapine 2.5 and 5 mg and lorazepam 1 mg at 2 hours compared with placebo. No statistically significant differences in extrapyramidal symptoms between the treatment groups were found. Lorazepam significantly increased somnolence compared with olanzapine and placebo (10% versus 4% and 3%).