Is acetazolamide similar to topiramate for reversal of antipsychotic-induced weight gain?

Acetazolamide (AZD), a sulfa-like moiety, is a potent, nonspecific inhibitor of carbonic anhydrase (CA) enzymes and has been demonstrated to decrease lipogenesis in adipose cells in in vitro cell culture studies. In contrast, topiramate (a sulfamate moiety) appears to inhibit specific (CA) enzymes II and V. Four placebo-controlled trials with topiramate have demonstrated positive results in weight loss. There is only anecdotal evidence that AZD may cause weight loss. The following case is of a 49-year-old African-American woman with a long history of schizoaffective disorder, hypertension, diabetes type II, stress incontinence, and obesity (body mass index, 45.5 kg/m2). Previous trials of topiramate demonstrated temporary but significant weight loss before AZD use. A 4 week washout period occurred before starting AZD, 250 mg twice daily. Significant weight loss of 11.5 lbs was seen over 4 weeks. During washout periods of either topiramate or AZD, her total mean weight was approximately 2 to 7 lbs higher than when she was treated with AZD. Although tolerance and side effects may limit the use of AZD as a safe and effective strategy for medication-related weight gain, the pharmacology may provide research insights into the causes and treatments of obesity.