Weight gain and atypical antipsychotic drugs

• weight gain with antipsychotic therapy is important as a risk factor for cardiovascular events and the development of type 2 diabetes mellitus, and because it may undermine adherence to treatment
• some patients gain substantial weight during treatment with atypical antipsychotics
  • weight gain appears to be commonest and greatest with clozapine and olanzapine; moderate with risperidone, sertindole and zotepine; and probably least with ami-sulpride and aripiprazole
  • weight gain is difficult to predict in the individual, but possible predictors include a good clinical response to treatment, an initial body mass index below 23kg/m2, and younger age
• the possibility of weight gain needs to be discussed with the patient before starting treatment. Ideally, a drug with a low tendency to increase weight is a better choice for a patient who is already obese or prone to weight fluctuations (1)
• clinicians should measure the patients' weight, height and body mass index before starting, and at intervals throughout, treatment

Reference:

1. Drug and Therapeutics Bulletin (2004); 42(8):57-60.