Psychopharmacology of olanzapine. A review

Olanzapine is a new atypical antipsychotic (Weaver, 1997). Both early development and clinical studies support its safe use. Clinical trials suggest that it is efficacious in treating positive symptoms in schizophrenia, and more efficacious for negative symptoms and depressive symptoms than traditional antipsychotics. In addition, the side-effect profile of olanzapine is favourable, with a low incidence of EPS and little increase in prolactin during acute-phase trials. At present, olanzapine appears broadly as good as the other novel atypical drugs. As a group, the atypical antipsychotics have been recommended for use as first-line therapy, in acute schizophrenic relapse, and for those who are responsive, but intolerant, to classical antipsychotic medication (Kerwin, 1994; Lieberman, 1996). The role of olanzapine in treating treatment-resistant patients is unproven, and data is awaited comparing olanzapine directly with clozapine. The current era of development of drugs for schizophrenia holds great promise, and it is the duty of all doctors to make patients aware of the benefits and risks of available treatments, and to enable them to choose.