background Weight gain is a side effect of antipsychotic drugs. It can lead to non-compliance, which has a negative influence on the course of schizophrenia.
aims In this review article various theories about the mechanisms to explain this weight gain are discussed. Studies, examining weight gain as a variable, are also discussed. Finally, advise to minimize weight gain in patients is given.
method Literature search was performed using Medline, the Cochrane Library and references of articles.
results Serotonin, histamine, adrenergic and muscarinic receptor binding plays a role in the mechanism of weight gain as a side effect of antipsychotic drugs. Also other factors play a role. Clozapine causes most weight gain of the atypical antipsychotic drugs, followed in descending order by olanzapine, sertindole, quetiapine and risperidone. Of the conventional antipsychotic drugs, chlorpromazine and thioridazine cause most weight gain.
conclusions Weight gain as side effect of antipsychotic drugs is caused by multiple factors. To limit the amount of weight gain and to maintain compliance, monitoring weight and informing patients about the possibility of weight gain is important. A medication-switch to a drug with less weight gain as a side effect might be considered.