Use of olanzapine in non-psychotic psychiatric disorders

The history of antipsychotic medications begins in the 1950s with chlorpromazine, developed originally as an antihistamine but found to be an aid in the reduction of symptoms of delusions and hallucinations. This phenothiazine derivative was followed by numerous others in the same class (e.g., thioridazine) and then by antipsychotics in other classes (e.g., the popular haloperidol of the butyrophenone class). This group of medications is associated with a number of unpleasant side effects and complications. These included extrapyramidal symptoms (EPS), orthostatic hypotension, hyperprolactinemia and last, but certainly not least, tardive dyskinesia (TD). As a consequence, other alternative antipsychotics were developed in which D(2) blockade effect generally associated with EPS and TD was offset by 5-HT(2) antagonism. The first of this class was clozapine; however, it is associated with agranulocytopenia of sudden onset as well as seizure induction. However, olanzapine, a close structural relative, was soon synthesised for treatment of psychosis and particularly schizophrenia (Zyprexatrade mark, Eli Lilly). It was released in the US in November 1996 with FDA approval for that indication. However, antipsychotics have always been used for other psychiatric disorders, aside from schizophrenia. This includes, in particular, mania, where chlorpromazine use predated lithium as an effective treatment. Other uses for antipsychotics have included other mood disorders, dementia, childhood disorders and personality problems. Here, information on the application of olanzapine to non-schizophrenic disorders is reviewed. Despite the fact that the research post-dates FDA approval in 1996, there was already sufficient evidence for olanzapine's effectiveness in acute mania to obtain approval from the US FDA in March 2000. Other research supports its use as adjunctive therapy in depressive disorders. Phase IV studies and case reports have found limited support for olanzapine's use in a variety of other psychiatric disorders, behavioural disorders of dementia (including Alzheimer's disease), pervasive developmental disorder of childhood, obsessive-compulsive disorder and borderline personality disorder. In each of these latter diagnoses, double-blind studies are either underway or are planned to establish efficacy.