Phentermine/topiramate for weight reduction and treatment of adverse metabolic consequences in obesity

Phentermine hydrochloride is a noradrenergic sympathetic amine approved for decades by the U.S. Food and Drug Administration (FDA) at doses as high as 37.5 mg/day for the short-term treatment of obesity. Topiramate is a sulfamate-substituted monosaccharide marketed since 1996, and approved by the FDA for seizure disorders at doses up to 400 mg/day and for the prevention of migraine headaches at doses up to 100 mg/day. Clinical trial data suggest topiramate promotes weight loss. The prescribing information of neither agent describes adverse drug interactions with the other. The controlled-release formulation of phentermine and topiramate at low, medium and full doses (with full dose containing 15 mg of phentermine hydrochloride and 92 mg of topiramate) promotes weight reduction, with clinical trial data supporting improvement in adiposopathic consequences leading to metabolic diseases. Reported adverse events with this combination agent are as expected, based upon knowledge of the individual components.