Olanzapine versus lithium in the acute treatment of bipolar mania: a double-blind, randomized, controlled trial.

Background: This multicenter, double-blind, randomized, controlled study conducted in China examined the efficacy and safety of olanzapine versus lithium in the treatment of patients with bipolar manic/mixed episodes.

Methods: Patients with bipolar manic or mixed episode (DSM-IV criteria) and Young Mania Rating Scale (YMRS) score> or =20 at screening received olanzapine (5-20 mg/day, n=69) or lithium carbonate (600-1800 mg/day, n=71) for 4 weeks. The primary outcome was mean change from baseline in Clinical Global Impressions-Bipolar Version Overall Severity of Illness (CGI-BP) score. Secondary efficacy measures included YMRS, Brief Psychiatric Rating Scale (BPRS), and Montgomery-Asberg Depression Rating Scale (MADRS) scores. Safety was also assessed.

Results: A significantly greater mean change was observed in olanzapine versus lithium patients in CGI-BP (Overall Severity) (P=0.009), YMRS (P=0.013), BPRS (P=0.032), and CGI-BP (Severity of Mania) (P=0.012) scores. More olanzapine than lithium patients experienced at least one adverse event possibly related to study drug (P=0.038). More olanzapine patients had a clinically significant weight increase (> or =7% of baseline weight) compared to lithium patients (P=0.009). More olanzapine patients completed the study than lithium patients, although this difference was not statistically significant (olz, 91.3%; lith, 78.9%; P=0.057).

Limitations: No placebo arm was included; however both treatments have previously been reported to be more effective than placebo.

Conclusions: These results suggest that olanzapine has superior efficacy to lithium in the acute treatment of patients with bipolar mania over a 4-week period. However, adverse events were experienced by a greater number of olanzapine patients than lithium patients.