Latest weight-loss research offers promising new options

August 20, 2001

Highlights from AMA briefing on obesity

 

Rx CARE

Latest weight-loss research offers promising new options

Americans are getting fat. This may not be earth-shattering news, but the unassuming public doesn't seem to be aware of the health consequences associated with obesity (defined as being more than 30% above ideal body weight).

The public mistakenly views obesity as a cosmetic problem rather than a major source of illness and death, according to William Dietz, M.D., Ph.D., who spoke recently at an American Medical Association media briefing on obesity in New York.

Dietz is the director of the division of nutrition and physical activity at the Centers for Disease Control & Prevention in Atlanta. He commented on an American Heart Association study that found that fewer than one-third of Americans knew that obesity, inactivity, or high cholesterol are associated with cardiovascular disease.

This is a huge educational problem that must be urgently addressed by the healthcare community. Pharmacists can educate their patients about the comorbidities associated with obesity—such as hypertension, hyperlipidemia, and diabetes—through consultation or by forming multidisciplinary teams with other practitioners, such as dietitians, to help implement weight-loss programs.

According to CDC, overweight and physical inactivity account for more than 300,000 premature deaths each year in the United States, second only to tobacco-related deaths. This underscores the need for newer therapeutic strategies to stem this growing epidemic, which is poised to become one of the biggest health concerns of the century.

Despite the alarming incidence of obesity, the medications available for the long-term treatment of this condition remain limited. Since obesity is a chronic disease, the short-term use of drugs is not recommended. Only two products, sibutramine (Meridia, Knoll Pharmaceutical) and orlistat (Xenical, Roche Laboratories), are approved by the Food & Drug Administration for the long-term treatment of obesity in conjunction with a reduced-calorie diet.

These drugs are not the "magic bullet," according to James Hill, Ph.D., but they are a legitimate tool that for many people can make the difference between success and failure. Hill is director of the Center for Human Nutrition at the University of Colorado Health Sciences Center in Denver. In many cases, losing just 5% to 10% of body weight may substantially improve a person's health.

Pharmacists can help patients by counseling them on the possible side effects as well as on the importance of following a low-fat diet and increasing their physical activity.

Orlistat may cause a decrease in the absorption of fat-soluble vitamins and so a multivitamin supplement is recommended when taking this drug. Sibutramine can cause an increase in heart rate and blood pressure and should be avoided in patients with hypertension, congestive heart failure, arrhythmias, or a history of stroke.

With regard to over-the-counter weight-loss products, including herbal and natural remedies, Hill advised that the pharmacist be skeptical in recommending any of these products. "The worry is that there are just so many things being advertised for weight loss with so little information [available] about whether they work or not," said Hill.

George Bray, M.D., professor of medicine at Louisiana State University Medical Center in New Orleans, talked about some exciting new studies showing initial positive results for weight loss. The furthest along is leptin, a hormone secreted by adipose tissue in proportion to adipose mass. Leptin initially had disappointing results, but studies are under way using different formulations. The hormone appears to act on receptors in the hypothalamus and periphery to reduce food intake and increase energy expenditures.

However, it appears leptin resistance develops rapidly, so researchers continued to search for newer strategies. This led to the serendipitous finding that ciliary neurotrophic factor (CNTF), under study to treat amyotrophic lateral sclerosis, produced severe anorexia and weight loss. A 12-week trial with CNTF demonstrated a dose-related weight loss.

A study showing that weight reduction is a function of the amount of calcium ingested led to a review of five clinical studies of calcium intake designed for osteoporosis prevention to explore the association between calcium intake and body weight. Relative to placebo, the calcium-treated patients exhibited a significant weight loss across nearly four years of observation.

There was also mention of Ortho-McNeil's antiepileptic, topiramate (Topamax), which was shown to produce an 11% to 12% weight loss in obese patients who participated in a one-year trial of the drug as a treatment for epilepsy. Similarly GlaxoSmithKline's anti-depressant bupropion (Wellbutrin) demonstrated a dose-related weight loss over a period of six months.

Tammy Chernin, R.Ph.

 



Tammy Chernin. Latest weight-loss research offers promising new options.

Drug Topics

2001;16:15.