Counterfeit OTC weight loss drug contains controlled drug

Counterfeit versions of GlaxoSmithKline's over-the-counter weight-loss product Alli have been found to contain a powerful prescription-only medicine that raises significant safety concerns for consumers, according to a US Food and Drug Administration alert.

Alli is an OTC drug containing 60mg of the pancreatic lipase inhibitor orlistat which works by binding fat in the gastrointestinal tract so that it is not absorbed by the body. The drug is on the whole well-tolerated: side effects are generally mild and only tend to occur when a patient continues to eat a high-fat diet when taking the product.

The counterfeit product encountered by the FDA contains sibutramine, another weight-loss drug that works by altering neurotransmitters in the brain, specifically blocking the reuptake of dopamine, norepinephrine, and serotonin.

Sibutramine is manufactured by Abbott Laboratories, under brand names such as Reductil, Meridia and Sibutrex, and is a Schedule IV controlled substance in the USA.

"Sibutramine is a drug that should not be used in certain patient populations or without physician oversight," notes the FDA in its alert. "Sibutramine can also interact in a harmful way with other medications the consumer may be taking," it goes on.

Most worryingly, patients taking the selective serotonin reuptake inhibitor (SSRI) class of antidepressants - which includes fluoxetine, sertraline, fluvoxamine and paroxetine - and certain migraine medications can develop a potentially life-threatening reaction known as serotonin syndrome when taken alongside sibutramine.

GSK encountered the counterfeit Alli among products sold over the internet, after receiving reports from consumers in December 2009. As yet there is no evidence that the fake has been sold through other channels such as retail stores.

The counterfeit has a number of differences from the genuine products, according to the FDA, including:

• Outer cardboard packaging missing a “Lot” code;
• Expiration date that includes the month, day, and year (e.g., 06162010); authentic Alli expiration date includes only the month and year (e.g.,: 05/12);
• Packaging in a plastic bottle that has a slightly taller and wider cap with coarser ribbing than the genuine product; Plain foil inner safety seal under the plastic cap without any printed words; the authentic product seal is printed with “SEALED for YOUR PROTECTION”;
• Contains larger capsules with a white powder, instead of small white pellets