May 6, 2010

BIRMINGHAM, Ala. - University of Alabama at Birmingham (UAB) researchers have found that an experimental drug that combines an appetite suppressant and a commonly used epilepsy medicine not only helped overweight and obese patients control hunger and lose weight, it also lowered patients' blood pressure.

The study, presented this week at the American Society of Hypertension annual meeting in New York by Suzanne Oparil, M.D., professor of medicine in the UAB Division of Cardiovascular Disease and director of the UAB Vascular Biology and Hypertension Program, showed that an oral, once-daily, low-dose, controlled-release combination of the appetite suppressant phentermine and the anti-seizure drug topiramate  resulted in significant weight loss, and improvement in both systolic and diasystolic blood pressure.

The drug, known by the trade name Qnexa®, is currently under review by the Food and Drug Administration for weight loss in clinically obese adults or overweight patients with weight-related diseases. Oparil is a consultant for Qnexa manufacturer Vivus.

"Today, 68 percent of men and women in the United States are overweight or obese," Oparil said. "This is a growing epidemic and has severe implications because obesity is associated with comorbidities such as cardiovascular disease, diabetes and hypertension.

"Patients taking this drug were able to lose clinically significant weight, saw clinically significant improvements in blood pressure and were able to sustain these health gains for a year," she said. "As such, we believe our study shows that this is a novel treatment that can lead to significant weight reduction in obese/overweight adults and may alleviate common obesity-related comorbidities such as hypertension."

Oparil said that in Qnexa, phentermine suppresses appetite, while topiramate, which is controlled-released, decreases appetite and increases satiety throughout the day. Topiramate also produces the blood pressure-lowering effects.

In this study, Oparil and her colleagues performed an analysis of three separate, previous Qnexa trials. Of the 3,987 subjects who were randomly assigned to placebo or one of three different doses of Qnexa in the CONQUR, EQUIP and EQUATE studies, the researchers found that weight loss was significantly greater for all of the doses of Qnexa at 28 and 56 weeks versus the placebo. The higher the dose of Qnexa, the more substantial the weight loss, and the more likely it was to be maintained over time, the study showed.

Qnexa, she said, also resulted in drops in systolic and diasystolic blood pressure at one year across all of the studies, and a sub-analysis of people with high blood pressure participating in the study showed that Qnexa also helped them to reduce the number of other blood pressure medications they were taking.

Oparil said the standard treatments for obesity, including diet and exercise, often achieve only marginal weight loss, and currently approved weight-loss agents often fail to achieve long-term efficacy due to safety or tolerability concerns. The need for a well-tolerated, safe, and effective weight loss therapy that can minimize obesity-associated comorbidity remains unmet, she said, but this drug shows promise.

About the UAB Division of Cardiovascular Disease

The UAB Division of Cardiovascular Disease emphasizes excellence in patient care, teaching plus basic and clinical research. Clinical research is closely associated with individual clinical cardiology services and encompasses a variety of opportunities and interactions with faculty associated with numerous large federal- and industry-supported clinical trials. UAB is an internationally renowned research university and academic health center whose professional schools and specialty patient care programs are consistently ranked as among the nation's top 50; find more information at www.uab.edu and www.uabmedicine.org