Xenical medication for weight loss, risk, caution, danger, liver injury, side effects, do the risks outweigh the benefits? Ray Sahelian, M.D.
March 15 2016

The diet drug Xenical, known generically as orlistat, produces weight loss by decreasing the amount of fat absorbed in the intestines. Studies have shown that this prescription medication promotes more weight loss than lifestyle modification alone. Xenical is used with a low-calorie diet to help you lose weight and to maintain your weight after weight loss. Xenical is used in patients with a certain weight who may also have high blood pressure, diabetes, high cholesterol, or heart disease. Xenical is in a class of drugs called lipase inhibitors. It works in the intestines, where it blocks some of the fat you eat from being absorbed and digested. This undigested fat is then removed in your bowel movements (BM). Xenical is a pharmaceutical drug manufactured by Roche and co-promoted in the U.S. by GlaxoSmithKline Consumer Healthcare. Over the counter orlistat is called by the brand name Alli. For more information on diet pills and products for appetite suppressants.


April 15, 2011 -- The consumer advocacy group Public Citizen is urging the FDA to immediately pull Xenical from the market. The group says the risk for liver, pancreas, and kidney damage greatly outweighs any potential weight loss benefits.


The use of this medication
Xenical is a weight loss medication that is taken with meals to inhibit the absorption of dietary fat. Xenical should be used in conjunction with a reduced-calorie diet that contains no more than 30 percent of calories from fat. Following such a diet maximizes weight loss and minimizes unwanted gastrointestinal treatment effects. Xenical (120 mg) is available with a prescription. Non-absorbed fat can lead to some changes in bowel habits. These changes are of concern for some people if they continue taking Xenical for six months or longer. Patients considering taking Xenical should tell their doctor if they are pregnant, nursing, taking cyclosporine, have food absorption problems or reduced bile flow. A daily multivitamin is recommended because Xenical can reduce the absorption of fat-soluble vitamins.


For long-term weight management, the FDA has approved 5 agents so fa: Orlistat, lorcaserin, phentermine/topiramate, naltrexone / bupropion, and liraglutide.


Xenical side effects
The long term safety of Xenical is of concern and consumers should weigh the benefits versus the risks when considering the use of this drug. A serious Xenical side effect could be pancreatitis.


J La State Med Soc. 2013. Orlistat-induced oxalate nephropathy may be dose-independent and present as a late manifestation.


August 2009 - FDA is reviewing Roche Holding AG's weight loss drug Xenical, and the over-the-counter version sold by GlaxoSmithKline, after receiving reports of liver injury in some patients. The FDA has received 32 reports between 1999 and 2008 of serious liver injury in patients taking the weight loss drug, which is known generically as orlistat. Six cases resulted in liver failure. Glaxo sells the over-the-counter version of the drug under the name Alli.

36 year old man presenting with pancreatitis and history of recent commencement of Xenical, Case report.
Nutr J. 2006.
Xenical is an anti-obesity drug licensed in the United Kingdom for 7 years. We present a case of a patient who developed pancreatitis four days after commencing Xenical. Case Presentation A 36 year old man presented to hospital with acute severe pancreatitis four days after starting a course of Xenical, a lipase inhibitor used in the treatment of obesity. A diagnosis of drug related pancreatitis was made by exclusion of other causes of pancreatitis; he was a teetotaller, had a normal serum calcium, had no family history of pancreatitis or hyperlipidaemia, no history of trauma and had no evidence of gallstones on Computerised Tomography scan (CT).  Xenical was the only drug that had been started recently and has been associated with pancreatitis previously. We found no case reports of similar cases, however 99 cases of Xenical related pancreatitis have been reported to the Food and Drug Administration (FDA), but no causative link has been found in clinical trials by the drug company. It is therefore not on the list of possible complications or side effects of the drug.


Xenical and gallstones
A review of Roche AG's Xenical has found a lin between the weight-loss drug and gallstones in patients of all ages. Thirty-seven U.S. cases of gallstones in Xenical patients were reported to the Food and Drug Administration between April 1999 and December 2006. Xenical, also known by its chemical name, orlistat, is approved in the United States and aims to prevent fat from being absorbed by the body. It is also available in an over- the-counter version called alli, licensed by GlaxoSmithKline Plc. Gallstones, which often do not trigger any symptoms, are formed by an excess of water, salt, cholesterol and other substances excreted from the liver and can cause painful blockages.

Xenical for Nonalcoholic Fatty Liver

A double-blind randomized placebo-controlled trial of Xenical for the treatment of nonalcoholic fatty liver disease.
Clin Gastroenterol Hepatol. 2006.

Few controlled studies have addressed the issue of effective medical treatment for nonalcoholic fatty liver disease (NAFLD). We herein assessed the effect of Xenical in patients with NAFLD. We performed a randomized, double-blind, placebo-controlled study on 52 patients with NAFLD diagnosed by ultrasound (US) and confirmed by liver biopsy (40 patients). The patients were randomized to receive either Xenical (120 mg 3 times daily for 6 months) or placebo. Fifty-two patients were recruited and 44 (mean age, 47.7 y; mean body mass index, 33) completed the study. Serum glucose and insulin levels were significantly higher in the Xenical group, which also presented a higher degree of fibrosis. Serum alanine transaminase (ALT) levels decreased significantly in both groups (48% vs 26%). There was a statistically significant reversal of fatty liver by US only in the Xenical group. Xenical improves serum ALT levels and steatosis on US in NAFLD patients, however there is the concern of elevated serum glucose and insulin levels.


Xenical and weight loss
In a study of obese adults who successfully lost a substantial amount of weight by dieting, taking Xenical, along with lifestyle modification, helped keep them from regaining the weight. The current study examined the ability of Xenical to prevent weight regain in 383 obese adults who had lost an average of 31 pounds (14 kg) on an 8-week protein-rich, very-low-energy diet. The 309 participants who lost 5 percent or more of their bodyweight then received lifestyle counseling for 3 years while taking either Xenical or a matching placebo pill daily. In the journal Diabetes Care, Dr. Bjorn Richelsen from Aarhus University Hospital, Denmark, and colleagues report that the two groups both regained some weight, but it was 5.3 pounds (2.4 kg) less among those who took Xenical. That is, Xenical patients regained an average of 4.6 kg, while placebo patients did about 7.0 kg. Diabetes Care, January 2007.


Xenical and blood pressure, hypertension
Xenical, a fat blocker sold by Roche Holding AG, may reduce high blood pressure (hypertension), while Meridia, an appetite suppressant sold by Abbott Laboratories, does not.


Use by children and teenagers
The number of young people in the UK taking weight loss pills has risen 15 fold in the past 8 years until 2009. A study published in the British Journal of Clinical Pharmacology in September 2009 estimates that about 1,300 young people in the UK are currently being prescribed the tablets, even though they are not approved for under-18s in the country. The study called for further research into the safety and efficacy of anti-obesity drugs in children and adolescents because of the increase in the numbers taking the drugs. More than three quarters are getting orlistat, marketed as Xenical by Roche and as Alli by GlaxoSmithKline, according to the study.