New weight loss pill - combination of two existing drugs

According to the latest research on obesity treatments there is now a new weapon in the battle for weight loss. It combines two existing drugs that have resulted in twice as much weight loss as the only approved long-term anti-obesity medication.

The combination is a mix of Phentermine and topiramate, sold under the brand name of Topamax. It was seen in clinical trials that the mix was twice as effective as orlistat, which is commercialized in some countries as Xenical or Alli, it said. This mix also has additional health benefits, including improved “markers,” or indicators, for blood pressure, sugar levels, lipids and inflammation, the study added.

Currently, there is only one drug approved by the Food and Drug Administration (FDA) for long-term weight loss: orlistat. It works by blocking absorption of fat in the gut, but doesn't affect appetite. Last fall, the FDA rejected the phentermine-topiramate combination for approval, after its maker Vivus had first submitted the drug, which it calls Qnexa; the FDA asked the company for further safety studies, especially on the risk of heart problems and birth defects.

Phentermine is the most widely prescribed short-term weight drug in the United States. Topiramate is an anti-epileptic approved for treating seizure disorders and migraines. It has been shown to work well for weight loss in obese patients with type 2 diabetes, but taken alone has also been linked to cognitive and psychiatric side effects. Lower doses taken with a controlled-release mechanism and in combination with other drugs would likely reduce those side effects, tests have shown.

The study led by Kishore Gadde of the Duke University Medical Centre, in Durham, North Carolina, spanned over 20 months with 2,487 overweight or obese adults with at least two major health-risk symptoms. The patients were divided into three groups. One group was given a once-a-day dose of 7.5 mg of Phentermine and 46 mg of topiramate, while a second group was given 15 and 92 mg of the same drugs, respectively. The third group was given look-alike placebos or dummies.

After 56 weeks of treatment, the low-dose group dropped, on average, 8.1 kilos (18 pounds) while the high-dose group shed 10.2 kilos (22 pounds). Patients given placebos lost 1.4 kilos (3.0 pounds). Overall, 62 percent of the low-dose patients lost at least five percent of body weight, while 70 percent in the high-dose cohort crossed the same threshold. Patients given placebos lost 1.4 kilos (3.0 pounds), with 21 percent sloughing five percent off their total weight. The two-drug treatment was well tolerated physically, with only sporadic cases of dry mouth and constipation. The high-dose group, however, showed a higher dropout rate due to adverse cognitive and psychiatric reactions, according to the study, which is published by The Lancet on Monday.

Kishore M. Gadde, who is director of the obesity clinical trials program at Duke University said, “The weight loss is impressive.” He added, “this is the first time the data are presented in a peer-reviewed journal.” Gadde explained, “this treatment led to significant improvement in excess weight-related diseases such as diabetes and high blood pressure and risk factors such as high cholesterol.” Those on the drug had a greater reduction blood pressure and improvement in so-called good cholesterol, HDL cholesterol, than those on placebo. Those who had diabetes at the study start and took the drug were less likely to need an increase in diabetes drugs than those on placebo.

Dr. Ananya Mandal

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.


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