MEDICATIONS: NATIONAL TRENDS IN USE OF ANTIOBESITY MEDICATIONS

May 13, 2003 — The use of antiobesity drugs peaked in 1997 and decreased after the withdrawal of fenfluramine-phentermine combination therapy (fen-phen, a prescription appetite suppressant) from the market (in 1997 after reports that it was associated with heart problems), and now remains above early 1990 levels, according to an article in the May 12 issue of The Archives of Internal Medicine, a journal of the American Medical Association.

According to background information in the article, obesity (defined as a body mass index, or BMI of 30 or more) has increased steadily in the United States from 15 percent in 1976 to 27 percent in 2000. Obesity contributes to several health problems including type 2 diabetes mellitus, hypertension, congestive heart failure, lipid disorders, arthritis and some cancers. The frustration of patients and physicians with unsuccessful weight loss using lifestyle changes (including diet and exercise) makes medication an attractive option, write the authors of the article.

In the mid-1990s, researchers became aware that the diet drug combination fen-phen was highly effective in helping people lose weight and fen-phen fueled tremendous interest in antiobesity medications. Beginning in 1996, reports of pulmonary hypertension and then heart valve abnormalities associated with fen-phen and dexfenfluramine (an active ingredient of fenfluramine) led to the withdrawal of fenfluramine and dexfenfluramine in September 1997. However, several other antiobesity medications were available.

Randall S. Stafford, M.D., Ph.D., of the Stanford Center for Research in Disease Prevention, Palo Alto, Calif., and colleagues investigated the use of antiobesity medication use before, during and after the 1997 withdrawal of fen-phen from the market. The researchers used data from the National Disease and Therapeutic Index (NDTI) from 1991 to 2002. The data included a sample of 13,452 patient visits for which a diagnosis of obesity was made.

The researchers found that in the second quarter of 1997, 2.5 million Americans were taking antiobesity medications, a fourfold increase over the previous two years. Although antiobesity medication use diminished following the withdrawal of fen-phen, current levels of use remain above those in the early 1990s. Phentermine has been the most commonly used antiobesity medication, and in 2002, 31 percent of drug-treated obese patients used phentermine.

The researchers also found that newly released medications including orlistat (used by 0.6 million patients) and sibutramine hydrochloride (used by 0.4 million patients) were used less often, and that most antiobesity medication use occurs in patients without other reported medical problems.

"Despite the events of 1997, there remains substantial physician willingness to use antiobesity medications," write the authors. "However, given the growing prevalence of obesity, the limits of currently available medications, and the widespread lack of attention physicians give to obesity, physicians should consider redirecting their energies elsewhere. While lifestyle modification strategies may have inherent frustrations, physicians may undervalue this approach and fail to use behavioral strategies and ancillary personnel that could make nondrug therapies more successful."