New Diet Pill Alli May Not Be a Wonder Drug, After All

By Anastacia Mott Austin

Starting tomorrow, customers may walk into any drug store and buy the new OTC diet drug Alli (also called orlistat in its clinical trials). Designed to block fat in the intestinal tract, the drug has been proven safe and at least mildly effective for moderate weight loss.

In clinical studies, Alli has been shown to block approximately 25 percent of the fat ingested at any one meal, if taken before the meal. "I have a lot of patients who want to eat a little extra fat, and they take this so they won’t absorb some of the fat that they eat," said Dr. George Blackburn to reporters. Dr. Blackburn is a professor at Harvard Medical School, and co-chairs the Reality Council, which is aimed toward preventing obesity. The Reality Council receives funds in the form of a grant from GlaxoSmithKline, the makers of Alli.

Dr. James Anderson, who heads the UK College of Medicine Metabolic Research Group, supervised the studies of OTC-strength orlistat, or Alli. "Our research showed that people taking orlistat and following low-fat diets lost almost five percent of their initial body weight, about seven to 15 pounds, over four months," said Anderson to the press.

Pronounced "ally," as in friend, Alli may not be so friendly to some, however. Side effects can be quite startling, say both experts and users of Alli’s prescription-strength sister drug, Xenical. They included excessive flatulence, unexpected uncontrollable bowel movements, diarrhea, upset stomach, and loose, oily stool. The product’s information guide, Are You Losing It? Losing Weight Without Losing Your Mind, includes a recommendation that until users know how their bodies will respond to Alli, they would be wise to bring a change of clothing or wear dark-colored pants when leaving their homes.

Dr. John Husted, a bariatric surgeon at the California Pacific Medical Center, told The San Francisco Chronicle, "Long-term, I think people are going to be unsatisfied with this drug. People lose weight in different ways, and for some people it might work, but I expect that to be a minority of people."

Some experts believe that an unintended result of the drug is to force people to choose lower-fat meals because of the unpleasant side effects of eating high-fat meals.

Some doctors who once prescribed Xenical, the stronger version of the drug, reported that their patients either did not return for prescription refills or only used Xenical for a short period of time, after which it seemed to lose its effectiveness.

In a related story, an FDA advisory committee voted unanimously yesterday to not recommend a different new diet drug, rimonabant, because of its potential side effects.

Though rimonabant has been marketed successfully in Europe, the committee voiced concerns that some patients could experience greater risk of depression and suicide. A U.S. News report stated that in clinical trials, patients taking rimonabant did lose significantly more weight than the control group, yet more than 25% of them reported side effects like increased depression and anxiety.