WASHINGTON — Citing the drug’s potential to damage the liver, pancreas, and kidneys, the watchdog group Public Citizen has ask the FDA to remove marketing approval orlistat (Xencial, Alli) — the only remaining FDA-approved weight loss drug.
The group sent a petition to agency commissioner Margaret Hamburg, MD, asking the FDA to ban the drug because its risks outweigh its “minimal clinical benefits.”
The drug already carries a black box warning for liver damage, which the FDA added to the label last year.
But Public Citizen claims the label warning is not enough.
The group said its own analysis of FDA adverse event reports found 47 cases of acute pancreatitis and 73 cases of kidney stones in patients receiving either the prescription or over-the-counter version of the drug.
The prescription version, marketed as Xenical, contains 120 mg of the drug and was approved in 1999, while Alli, the over-the-counter version approved in 2007, contains half of that.
Several physicians contacted by MedPage Today and ABC News said they wouldn’t be affected by a ban on the drug because they don’t prescribe or recommend it.
"I have never recommended this drug over the counter, nor have I written a prescription," Randy Wexler, MD, MPH, of Ohio State University, said in an email.
Lee Green, MD, of the University of Michigan, said even in controlled trials, in which participants are motivated and have lots of support, the drugs only helped them “lose a few pounds.”
"The way they’re used in the real world, by obese patients who mostly don’t do the diet and exercise that is supposed to go with them, they make so little difference," he said.
Those opinions are reflected in a trend of drooping sales and prescriptions.
Last year sales of Alli totaled $84 million — down from $145 million in sales when it debuted in 2007. Similarly, prescriptions for Xenical fell from 2.6 million in 2000 to about 110,000 in 2010, according to data from Public Citizen.
Orlistat works by inhibiting enzymes that break down fat, enabling it to be excreted instead of absorbed in the small intestine.
This process, however, can prevent the absorption of certain fat-soluble vitamins, including vitamins A, D, E, and K, the group said.
The physicians who were contacted said it can also lead to diarrhea or stool leakage.
Orlistat remains the only pharmacological option for the treatment of weight loss. Last year, the FDA rejected three investigational weight loss drugs — Qnexa, Lorqess, and Contrave — and the other approved drug, sibutramine (Meridia) was removed from the market.
This article was developed in collaboration with ABC News.