paliperidone palmitate), which do not appear to carry the same risk. PDSS is characterized by symptoms of delirium (e.g. confusion, difficulty speaking, and uncoordinated movements) and sedation. Most people with PDSS exhibit both delirium and sedation (83%). Although less specific to PDSS, a majority of cases (67%) involved a feeling of general discomfort. PDSS may occur due to accidental injection and absorption of olanzapine pamoate into the bloodstream, where it can act more rapidly, as opposed to slowly distributing out from muscle tissue. Using the proper, intramuscular-injection technique for olanzapine pamoate helps to decrease the risk of PDSS, though it does not eliminate it entirely. This is why the FDA advises that people who are injected with olanzapine pamoate be watched for 3 hours after administration, in the event that PDSS occurs. Animal toxicology
Olanzapine has demonstrated carcinogenic effects in multiple studies when exposed chronically to female mice and rats, but not male mice and rats. The tumors found were in either the liver or mammary glands of the animals. Discontinuation
The British National Formulary recommends a gradual withdrawal when discontinuing antipsychotics to avoid acute withdrawal syndrome or rapid relapse. Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite. Other symptoms may include restlessness, increased sweating, and trouble sleeping. Less commonly, vertigo, numbness, or muscle pains may occur. Symptoms generally resolve after a short time.Tentative evidence indicates that discontinuation of antipsychotics can result in psychosis. It may also result in reoccurrence of the condition that is being treated.
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.