Olanzapine pamoate for the treatment of schizophrenia--a safety evaluation

Non-adherence to long-term treatment is a major issue for patients with schizophrenia and is associated with an increased risk of relapse. Long-acting injectable (LAI) antipsychotics can offer a useful option to improve adherence. Due to the type of sustained-release mechanism, olanzapine pamoate (OLAI) can differ in safety as compared with oral olanzapine. Recent safety data concerning olanzapine pamoate required an update of previous systematic reviews.

Safety data were found in US and EU clinical trial registries, and a literature search was undertaken using the databases PubMed and EMBASE to find all relevant published studies. Where appropriate, the number needed to harm and 95% confidence interval for categorical safety outcomes were calculated.

The safety profile of OLAI was similar to the well-known safety profile of oral olanzapine, except for the risk of occurrence of post-injection delirium/sedation syndrome (PDSS). Olanzapine pamoate can be a choice for schizophrenic patients with a history of response to and acceptable tolerance of oral olanzapine, who have easy access to mental healthcare settings with emergency services for the treatment of PDSS. Long-term, prospective studies assessing the efficacy and safety of OLAI and head-to-head comparisons with other LAI and oral antipsychotics are needed.