Olanzapine pamoate, a long-acting depot preparation of olanzapine, is being evaluated by regulatory agencies for the treatment of schizophrenia. Clinical trial information was accessed by on-line query of http://www.pubmed.gov, http://www.clinicaltrials.gov and http://www.fda.gov, along with an examination of poster presentations at scientific meetings held in 2008.
Two double-blind randomised clinical trials of olanzapine pamoate were conducted and demonstrate efficacy for both the acute treatment of schizophrenia and for the maintenance of antipsychotic response. Long-term open-label studies provide additional information on safety. The overall tolerability profile for olanzapine pamoate is similar to that for the oral formulation; however, with the depot there is a risk of a postinjection delirium sedation syndrome which resembles an overdose of oral olanzapine and which occurs in 0.07% of injections, requiring patients to be observed for 3 h after injection. At present, there are no studies available that directly compare olanzapine pamoate with other antipsychotics other than oral olanzapine.