A consumer watchdog group in the U.S., Public Citizen, has petitioned the U.S. Food and Drug Administration (FDA) to withdraw the prescription diet drug Xenical (orlistat) from the market; the group also want the FDA to refuse approval for the weight-loss pill to be made widely available over the counter.
Public Citizen's petition is based on findings from the pharmacology review of Roche's own data and a recent independent confirmation that Xenical causes pre-cancer in the colon of rats.
Public Citizen has an excellent track record of identifying dangerous drugs well before federal regulators take action to ban or put warnings on these drugs.
Public Citizen alerted consumers about the dangers of Vioxx, Ephedra, Bextra, Rezulin, Baycol, Propulsid and many other drugs years before the drugs were pulled from the market.
Last week the FDA granted drug company GlaxoSmithKline conditional approval for the drug to be sold without a prescription as long as it met certain undisclosed criteria.
Roche and GlaxoSmithKline have a promotion agreement for Xenical in the US.
Dr. Sidney Wolfe, director of Public Citizen's Health Research Group, says the failure to ban the prescription version of the drug, or to make it much more widely available by allowing OTC sales is a decision that is likely to increase the risks of cancer as recent data has linked the drug to precancerous colon lesions in animal studies.
The advocacy group says a December 2005 study confirmed earlier company data showing Xenical can cause abnormal cell growth in the lining of the colon.
Experts widely recognize the lesions as an early indicator of cancer.
The study which was published in the journal Cancer Letters, found "a significant increase" of colon lesions in rats given Xenical regardless of whether they were on high-fat or standard diets.
Xenical comes in 120-milligram capsules to be taken three times a day with meals. The proposed nonprescription version, called Alli, comes in 60 milligram tablets with one to two taken with meals.