A team of Canadian researchers, led by Dr. Matthew Weir of the University of Western Ontario, noticed an increase in kidney damage among people consuming the weight loss drug Orlistat, sold as "Xenical".
Using Ontario health data, they found that the incidence of kidney damage needing hospitalisation was only 0.5% prior to starting the drug Orlistat. However once the drug was started for weight reduction, they found that the incidence of hospitalisation. These findings were recently published in Archives of Internal Medicine.
AdvertisementBetween January 2002 and March 2008, among 953 new orlistat subjects, five patients experienced a kidney injury event in the year prior to starting on the diet pill. Wherein, 18 patients experienced an event within 12 months after filling their prescription (p=0.01). Dr. Weir, as a "test of specificity," also tracked upper GI bleeding in the same fashion and found hardly any differences in rates of upper gastrointestinal bleeds before and after orlistat consumption.
Dr. Weir, who authored the study, said "A few case reports found kidney problems in people on Xenical, which were not originally listed as the drug's side effects". He was quick to add further that, "I would like to make it clear that this study should be interpreted cautiously. It is observational and cannot prove causality".
Drug-safety watchdog "Public Citizen" sent a letter to FDA demanding that the company should remove both prescription and OTC Orlistat from the market, citing new data obtained from FDA adverse-reaction files. This data included 73 cases of kidney stones and 47 cases of acute pancreatitis. Previously, U.S. health officials also warned against rare cases of liver damage in patients on Roche's Xenical and GlaxoSmithKline's Alli. The active ingredient of both drugs (orlistat) inhibits the absorption of fat in the gut.
Dr. Donald E. Greydanus, a Pediatrician at Michigan State University, who was not a part of the study warned, "This is an important outcome and it illustrates that anyone taking "so-called-weight loss" pills should be under the strict scanner of a trusted physician."
Dr. Weir concluded by saying, "The take-home message is that patients on orlistat should have their kidney function carefully monitored on a regular basis."