PTINR.com
Alli & Warfarin
Wednesday, August 1, 2007
PTINR.com Staff
Bloating, gas and diarrhea is not all you can look forward to with Alli for weight loss, a drug interaction with warfarin is likely as well.
A battle over a $2 a day over the counter weight loss tablet escalated between GlaxoSmithKline and Roche the manufacturers and consumer group Public Citizen. The medication is called Alli (Orlistat). The drug works by blocking the absorption of fat and therefore causes weight loss when combined with a low-fat diet and exercise.
Manufactured by Roche, alli hit the retail stores in June 2007. Indicated for consumers over 18 – alli is raising serious concerns from the medical community despite controlled trials, particularly for the potential for increased risk of colon cancer and interactions with warfarin (Coumadin ®).
The manufacturers state alli is not a wonder drug and weight loss is modest when patients are compliant with proper diet and exercise.
“The efficacy of alli is not as desirable. A study conducted by Dr. James Anderson of the University of Kentucky and presented at the 2005 annual meeting of NAASO, the Obesity Society in Vancouver, British Columbia shows that during a course of four months, overweight people who were on a low calorie and low fat diet and also used the drug lost 5 percent of their baseline weight and those who were on diet only lose 3.3 percent.
The drug can help lose 50 percent more weight when a dieter follows a weight loss program including use of a low calorie, low fat diet and exercise, designed by the drug marketer. If one could lose 10 pounds in a course of four or six months following a low calorie, low fat diet and doing required physical exercise, he could lose 5 extra pounds when he also uses alli.” Foodconsumer.org
Researchers cautioned its use as no long term studies have been completed. Blocking the absorption of fat has a direct affect on fat-soluble nutrients including vitamins D, E and K. Vitamin K plays a significant role in maintaining stable INR test results for those taking Coumadin®. The FDA recommends patients who take alli also consider taking a multi-vitamin. Warfarin patients are encouraged to clear their multi-vitamin with their physician.
In a statement by Dr. Sidney Wolfe of the consumer organization:
“In opposing the over-the-counter approval a year ago, we stated that “the switch of orlistat to OTC status would be a serious, dangerous mistake in light of its marginal benefits, frequent co-existence of other diseases, common, bothersome [gastrointestinal] adverse reactions, significant inhibition of absorption of fat soluble vitamins [A, D, K and E], and problematic use in the millions of people using the blood thinner warfarin (Coumadin)” (the latter because of orlistat-induced Vitamin K deficiency).
We strongly urge people not to use this potentially dangerous drug, and we predict that, like the rapidly declining sales of the prescription version, the over-the-counter version will turn out to be a loser after enough people have a bad experience with it.”
Patients taking Coumadin (warfarin) are cautioned against starting or stopping alli-based products as an increase in INR test results can be expected due to the inhibition of vitamin K. An increased INR is closely associated with an increase in bleeding risk.
Alli is also available in non-prescription form and sold in major retail stores such as Wal-Mart.
After weighing the significant GI side-effects, potential link to cancer and interaction with warfarin – patients may be better off eating a healthy diet and going for a walk on a regular basis for weight control.