Olanzapine pamoate for the treatment of schizophrenia.

INTRODUCTION: Nonadherence is still a major problem in the long-term treatment of schizophrenia. Long-acting injectable or depot atypical antipsychotics are associated with better maintenance. Olanzapine pamoate, available since 2010, is the second depot atypical antipsychotic. AREAS COVERED: This review covers data on the efficacy and tolerability/safety of olanzapine pamoate, the long-acting formulation of the atypical antipsychotic olanzapine. Administered as a pamoate salt, it has an elimination half-life of 30 days, allowing a 2- or 4-week injection interval. Antipsychotic efficacy was documented in an 8-week trial in 404 acutely ill schizophrenia patients with maintenance therapy in a 24-week trial in 1065 chronic patients. The side-effect profile is comparable to that of oral olanzapine. The most relevant adverse event is the post-injection delirium/sedation syndrome, occurring at a rate of 0.07% of injections or 1.4% of patients. It requires administration by qualified personnel in settings where a post-injection observation period for 3 h by medical personnel is available. EXPERT OPINION: Olanzapine pamoate is an efficacious formulation, particularly for patients with a history of good response to oral olanzapine and doubtful adherence. Psychiatrists should reconsider their negative attitudes toward long-acting or depot antipsychotics and should offer this administration to the majority of patients, not only to a negatively selected population.