In contrast, pooled second-generation antipsychotics showed superiority to first-generation antipsychotics only against the discontinuation, negative symptoms (with a much larger effect seen among industry- compared to government-sponsored studies), and cognition scores. Olanzapine caused less extrapyramidal side effects and less akathisia, but caused significantly more weight gain, serum cholesterol increase, and triglyceride increase than haloperidol.A 2012 review concluded that among ten atypical antipsychotics, only clozapine, olanzapine, and risperidone were better than first-generation antipsychotics. A 2011 review concluded that neither first- nor second-generation antipsychotics produce clinically meaningful changes in CGI scores, but found that olanzapine and amisulpride produce larger effects on the PANSS and BPRS batteries than five other second-generation antipsychotics or pooled first-generation antipsychotics. A 2010 Cochrane systematic review found that olanzapine may have a slight advantage in effectiveness when compared to aripiprazole, quetiapine, risperidone, and ziprasidone. No differences in effectiveness were detected when comparing olanzapine to amisulpride and clozapine. A 2014 meta-analysis of nine published trials having minimum duration six months and median duration 52 weeks concluded that olanzapine, quetiapine, and risperidone had better effects on cognitive function than amisulpride and haloperidol. Bipolar disorder
Olanzapine is recommended by the National Institute for Health and Care Excellence as a first-line therapy for the treatment of acute mania in bipolar disorder. Other recommended first-line treatments are haloperidol, quetiapine, and risperidone.
A rise in prolactin is seen in about half of patients on olanzapine compared to over 90% of those taking risperidone, and enduring increases were less frequent in those taking olanzapine.It is not recommended to be used by IM injection in acute myocardial infarction, bradycardia, recent heart surgery, severe hypotension, sick sinus syndrome, and unstable angina.Several patient groups are at a heightened risk of side effects from olanzapine and antipsychotics in general. Olanzapine may produce nontrivial high blood sugar in people with diabetes mellitus. Likewise, the elderly are at a greater risk of falls and accidental injury. Young males appear to be at heightened risk of dystonic reactions, although these are relatively rare with olanzapine. Most antipsychotics, including olanzapine, may disrupt the bodys natural thermoregulatory systems, thus permitting excursions to dangerous levels when situations (exposure to heat, strenuous exercise) occur.Other side effects include galactorrhea, amenorrhea, gynecomastia, and erectile dysfunction (impotence). Paradoxical effects
Olanzapine is used therapeutically to treat serious mental illness. Occasionally, it can have the opposite effect and provoke serious paradoxical reactions in a small subgroup of people, causing unusual changes in personality, thoughts, or behavior; hallucinations and excessive thoughts about suicide have also been linked to olanzapine use. Drug-induced OCD
Many different types of medication can create or induce pure obsessive-compulsive disorder (OCD) in patients who have never had symptoms before. A new chapter about OCD in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (2013) now specifically includes drug-induced OCD.