Comparing Atypical Antipsychotics

(A) Schizophrenia

* Clozapine is superior to Olanzapine in preventing suicide attempts and worsening suicidal behavior in patients at high risk.
* Clozapine along with Olanzapine have lower rates of discontinuation of drug for any reason compared to other antipsychotics.
* Asenapine has higher rates of extrapyramidal side effects and more severe symptoms than olanzapine.
* Some studies also found risperidone and paliperidone had higher rates of extrapyramidal symptoms compared to olanzapine.
* Risperidone was found to result in more frequent or more severe sexual dysfunction symptoms than quetiapine, but was similar to extended-release paliperidone or ziprasidone.

* Among adolescents with schizophrenia, quetiapine was not superior to placebo based on response rate, but was superior based on improvements measured by the Positive and Negative Syndrome Scale.
* Women had greater improvements than men with clozapine and with olanzapine.

(B) Bipolar Disorder

* In manic or mixed episode, no significant differences were found between risperidone and olanzapine or asenapine and olanzapine for quality of life, response, or remission outcomes.
* Asenapine resulted in a higher risk of stopping the drug due to adverse events than olanzapine, but weight gain was greater with olanzapine.
* Weight gain was also greater with olanzapine compared to risperidone, but there were no differences in extrapyramidal symptoms or rates of discontinuations due to adverse events.

* In depressed episode, compared to placebo, only olanzapine and quetiapine (both immediate and extended-release) have evidence of significantly increasing the proportions of patients who achieve response and remission.

* In children and adolescents, compared to placebo, the following drugs have all been shown to increase the proportions of children and adolescents who achieve treatment response and remission: aripiprazole, olanzapine, immediate-release quetiapine, and risperidone. Overall however, the evidence is limited.

(C) Depression

* The rate of treatment response was improved by the addition of aripiprazole, quetiapine (immediate and extended-release), and risperidone.
* Observational evidence suggests that use of antidepressants (SSRIs) plus olanzapine is associated with significantly greater weight gain than SSRIs plus either quetiapine or risperidone.

(D) Dementia

* the best evidence found similar rates of response and withdrawal, and no differences in clinical outcome measures for olanzapine, risperidone, and quetiapine.

(E) Developmental and Behavioral Disorders

* Compared with placebo, risperidone, aripiprazole, and olanzapine improve behavioral symptoms in children with pervasive developmental disorders such as autism.
* Risperidone and quetiapine showed efficacy in children and adolescents with disruptive behavior disorders such as conduct disorder.


SOURCE: PubMed Clinical Q&A [Internet].Laura Dean, MD. February 11, 2011.