FDA panel backs OTC orlistat, with some concern: the advisory panel was troubled about the drug's interactions with warfarin and cyclosporine.(News)

BETHESDA, MD. -- The advisory panel that gave near-unanimous support for making orlistat available without a prescription also voiced several concerns about the drug's potential for interactions with cyclosporine and warfarin, its limited efficacy in mildly overweight people, and its effectiveness for maintaining weight loss after 6 months of use.

At a joint meeting of the Food and Drug Administration's nonprescription drugs advisory committee and the endocrinologic and metabolic drugs advisory committee last month, panel members voted 11-3 in favor of making 60-mg capsules available over the counter for weight loss.

GlaxoSmithKline Inc. (GSK) is proposing that orlistat be approved for promoting weight loss in conjunction with a reduced-calorie and low-fat diet in overweight people. The recommended dose would be one to two capsules three times a day with meals for a treatment duration of up to 6 months.

Orlistat, a nonsystemic drug that works locally in the GI tract to prevent absorption of up to 30% of dietary fat, has no effects on the central nervous system, is not addictive, and has no harmful cardiovascular effects. Gastrointestinal side effects include oily spotting, fecal incontinence, fecal urgency, and oily stools.

Since 1999, 120-mg orlistat capsules have been available by prescription as Xenical in the United States. The recommended prescription dose is 120 mg three times a day for people who are obese. The 120-mg capsules will continue to be available by prescription for managing obesity and for patients who should be treated by a physician, according to GSK Consumer Health Care.

If approved for over-the-counter (OTC) use, the 60-mg capsule will be marketed as Alli (pronounced ally), and will be the first medication for weight loss to be approved for nonprescription use. Other OTC products promoted for weight loss are regulated as dietary supplements.

Orlistat has been studied in more than 100 clinical trials involving a total of 30,000 patients, with data on up to 4 years of treatment and has been used in 22 million people, according to GSK. In support of the OTC approval, the company provided data from three clinical trials where the 60-mg dose was tested over 4-6 months, a label comprehension study, and an "actual use" study.