ObjectiveTo assess the effectiveness and safety of oral olanzapine treatment transitioned from rapid-acting intramuscular olanzapine (RAIM) in patients with acute agitation associated with schizophrenia in a real-world clinical setting.MethodsThe postmarketing surveillance study with a 3-day observational period after the last RAIM administration was conducted (original study). Following this, an extended study was added for patients who received oral olanzapine after RAIM administration during the original study period, in order to additionally observe them for 7 days after initial RAIM administration. Effectiveness and safety from initial RAIM administration were evaluated using the Positive and Negative Syndrome Scale-Excited Component score and treatment-emergent adverse events (TEAEs), respectively.ResultsThe effectiveness and safety analysis set included a total of 521 and 522 patients, respectively. A majority of patients received 10 mg of RAIM (475/522 patients, 91.0%). The mean ± SD total Positive and Negative Syndrome Scale-Excited Component score was 23.6±6.2 (n=318) at baseline (before initial RAIM administration), 17.4±6.8 (n=280) at 2 hours after initial administration, 16.2±6.8 (n=246) 2 days after final administration, 14.9±6.2 (n=248) 3 days after final administration, 13.8±5.9 (n=242) 4 days after final administration, 13.2±5.8 (n=221) 7 days after initial administration, and 13.4±6.2 (n=351) at final observation (with the last observation carried forward approach), showing that reduction in agitation seen with RAIM was sustained with oral dose of olanzapine. The most common TEAEs were dyslalia and somnolence (each event occurred in four patients), and abnormal hepatic function and constipation (occurred in three patients). One serious adverse event of sudden cardiac death occurred after transitioned to oral olanzapine with many other antipsychotic drugs.ConclusionIn the treatment of acute agitation associated with schizophrenia, RAIM could be generally transitioned to oral olanzapine without exacerbating adverse events or losing treatment effect.