Weight gain and adverse metabolic effects of second generation antipsychotics are a serious matter of concern.
Noting that weight gain and metabolic adverse effects are reliable risk factors for premature cardiovascular morbidity and mortality, New York researchers have stressed the need for new therapeutic interventions that might not pose such serious danger.
As the pharmacology of antipsychotic-induced weight gain is largely not understood, the development of targeted pharmacological interventions has proven difficult.
Hence Dr CU Correll, Psychiatry Research, The Zucker Hillside Hospital, and colleagues sought to collate past studies to get at some idea of the problems posed by the antipsychotics.
Across 32 studies including 1482 subjects, 15 different medications were tested, including metformin, reboxetine, rosiglitazone, sibutramine, topiramate, and sibutramine.
They observed in their article published in the Neuropsychopharmacology journal, "Although the observed weight loss and more isolated metabolic improvements with some agents reached statistical significance, the magnitude of these changes was modest. Even in studies with the most pronounced effects, subjects only lost part of the weight that they likely accrued during antipsychotic treatment. Although metformin outperformed other agents that have been studied against placebo, the current evidence is too limited to support its regular clinical use as an adjunctive medication. Data regarding the metformin related, rare, but potentially fatal side effect of lactic acidosis, particularly in elderly and those with compromised renal function, and its new-found association with the accumulation of beta-amyloid, a factor in the pathogenesis of Alzheimer's disease, alter the risk-benefit ratio in the elderly.
"However, the results do support further investigation of the risks and benefits of metformin in large, well-controlled trials in comparison with lower risk interventions such as switching to an antipsychotic medication with a lesser cardio metabolic burden, healthy lifestyle interventions and nutritional counseling.
"Studies are needed that examine the mechanisms of antipsychotic-induced weight gain and metabolic abnormalities to enable the development and testing of more targeted interventions that are hoped to be associated with greater weight loss efficacy and improved health outcomes in patients requiring antipsychotic treatment."