Orlistat diet pill, safety, danger, risks, liver disease, review of side effects and danger
January 20 2016 by
Ray Sahelian, M.D.


Orlistat is used with a low-calorie diet to help you lose weight and to maintain your weight after weight loss. Orlistat is used in patients with a certain weight who may also have high blood pressure, diabetes, high cholesterol, or heart disease. Orlistat is in a class of drugs called lipase inhibitors. It works in your 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). Over the counter orlistat is called by the brand name Alli. The brand name of prescription orlistat is called Xenical.
   Orlistat is a lipase inhibitor. Lipases are required for digestion and absorption of dietary lipids and fat-soluble vitamins and carotenoids. If you would like to lose weight naturally, see weight loss.


Drug Metab Pharmacokinet. Jan 14 2014. Modeling and simulation of orlistat to predict weight loss and weight maintenance in obesity patients. Orlistat is used clinically worldwide as anti-obesity drug. It is a chemically synthesized hydrogenated derivative of lipstatin and is an inhibitor of gastric and pancreatic lipases. It has been found to reduce the absorption of dietary fat in the gastrointestinal tract.


Orlistat reduces absorption of vitamins and nutrients

Orlistat is a weight loss medication that is taken with meals to inhibit the absorption of dietary fat. Orlistat 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. Prescription orlistat (120 mg) is Xenical. Non-absorbed fat can lead to some changes in bowel habits. These changes are of concern for some people if they continue taking orlistat for six months or longer. Patients considering taking orlistat 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 orlistat can reduce the absorption of fat-soluble vitamins.
   Orlistat treatment is associated with significant decreases in plasma concentrations of carotenoids such as alpha- and beta-carotene.


Effects of orlistat therapy on plasma concentrations of oxygenated and hydrocarbon carotenoids.
Lipids. 2006. Human Nutrition & Metabolism Research and Training Center Graz, Institute of Molecular Biosciences, Karl-Franzens University, Austria.
Orlistat is a lipase inhibitor that is applied for treating obesity. Lipases are required for digestion and absorption of dietary lipids and fat-soluble vitamins and carotenoids. The aim of this study was to compare the effects of orlistat therapy on plasma concentrations of oxygenated (beta-cryptoxanthin, lutein/zeaxanthin) and hydrocarbon (alpha-, beta-carotene, lycopene) carotenoids. Six patients with a body mass index (BMI) > or = 30 kg/m2 received 360 mg/d orlistat over 4.5 mon. In conclusion, even though weight loss was not significant, orlistat therapy was associated with significant decreases in plasma concentrations of the highly lipophilic hydrocarbon carotenoids, alpha- and beta-carotene.


American adults think weight-loss supplements are safe and effective. More than 60 percent of the 1,444 telephone respondents, all of whom had made significant efforts to lose weight, said that such supplements have been tested and are proven to be safe. Over half (54 percent) wrongly stated that such supplements are approved by the U.S. Food and Drug Administration. There are currently no over-the-counter drugs for weight loss approved by the FDA. The survey, conducted by the University of Connecticut's Center for Survey Research & Analysis (CSRA), was presented at the Obesity Society's annual meeting, in Boston. The poll was funded by drug maker GlaxoSmithKline, which makes the prescription weight loss drug orlistat, brand named Xenical. Earlier in 2006, GlaxoSmithKline received conditional FDA approval for an over-the-counter version of orlistat, to be sold as Alli.


Orlistat side effects, danger
Serious orlistat side effects could be pancreatitis and liver damage. The most common are gastrointestinal.


Diabetes Metab. 2015. Weight loss at a high cost: Orlistat-induced late-onset severe kidney disease. This report describes a case of kidney failure secondary to orlistat, a lipase inhibitor commonly used in the treatment of obesity. An 80-year-old man with type 2 diabetes who was being treated with orlistat developed rapidly progressive kidney failure. Low-grade albuminuria argued against diabetic nephropathy. Renal biopsy showed tubulointerstitial nephritis associated with numerous calcium oxalate crystals. Enteric hyperoxaluria was attributed to the orlistat treatment. The latter was stopped and the patient received calcium supplements. Six months after orlistat withdrawal, oxaluria was normalized and kidney function stabilized. Oxalate nephropathy may result from hyperoxaluria secondary to orlistat treatment. This suggests that kidney function and oxaluria be closely monitored in patients taking orlistat.


2009 - The US Food and Drug Administration is reviewing 32 reports of serious liver injury, including 6 cases of liver failure, in patients taking the weight loss drug orlistat, marketed as the prescription drug Xenical or the over-the-counter medication alli. Thirty of the adverse events occurred outside the United States.

36 year old man presenting with pancreatitis and history of recent commencement of Orlistat, Case report.
Nutr J. 2006.
Orlistat 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 orlistat. Case Presentation A 36 year old man presented to hospital with acute severe pancreatitis four days after starting a course of Orlistat, 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). CONCLUSIONS: Orlistat 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 orlistat 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.


Orlistat diet pill over the counter
2007 - The Food and Drug Administration approved the fat-blocking weight-loss pill orlistat, which has been available by prescription, in a reduced-strength version over the counter. The new version will be sold as "alli" by GlacoSmithKline PLC. Xenical, the prescription version, is made by Roche Holding AG. Alli diet drug is intended for people 18 and older to use along with a reduced-calorie, low-fat diet and exercise. Alli is the first nonprescription drug approved by the FDA for the purpose of weight loss. When taken with meals, orlistat blocks the absorption of about one-quarter of any fat consumed. That fat -- about 150 to 200 calories worth -- is passed out of the body in stools, which can be loose as a result. FDA recommends users take a multivitamin when using Orlistat. The new drug would contain half the dose of orlistat prescription capsules. The price has not been set but is expected to run $1 to $2 a day,. The company estimated 5 million to 6 million Americans a year would buy the drug over the counter. The Food and Drug Administration said the most common side effect of the product is a change in bowel habits including loose stool and some oily spotting. Eating a low-fat diet will reduce the likelihood of this side effect.


Orlistat and LDL Cholesterol
Data presented at the 2006 Annual Scientific Meeting of NAASO, The Obesity Society, found that low-dose orlistat (60 mg) in conjunction with a reduced-calorie diet, provided greater reductions in LDL cholesterol and weight loss when compared to treatment with placebo and a reduced-calorie diet. The data demonstrate that the effect of low-dose orlistat on change in LDL cholesterol persisted even after correcting for weight loss, showing the reduction in LDL cholesterol was independent of weight loss. In addition, a significantly greater number of patients with elevated LDL cholesterol levels at baseline had improved LDL cholesterol levels that shifted to a normal range after treatment with low-dose orlistat for 1 year. The results were based on two multi-center, double-blind, randomized, placebo-controlled clinical trials of 576 patients which were conducted over a 2-year period to compare the differences in weight loss and LDL cholesterol levels of 60 mg orlistat -treated versus placebo-treated subjects, with both groups consuming a reduced-calorie diet. Study results found that approximately 38 percent of orlistat -treated subjects had a favorable shift in their LDL cholesterol level in comparison to 11 percent in the placebo group. "These study results are significant in showing the added health benefit of taking low-dose orlistat," said Vidhu Bansal, PharmD, Director of Medical Affairs, GlaxoSmithKline Consumer Healthcare. "Because high cholesterol levels are often associated with overweight and obesity, we were excited to see the positive effect low-dose orlistat had. LDL cholesterol levels returned to a normal level after 1 year of taking the medication in a significantly greater number of patients on 60 mg of orlistat with elevated LDL levels at baseline and there was a persistent reduction in LDL cholesterol levels, even after correcting for weight loss." Currently under review by the U.S. Food and Drug Administration (FDA), orlistat 60 mg, which GlaxoSmithKline Consumer Healthcare proposes to market under the brand name alli (pronounced AL-eye), would be the only FDA-approved weight loss medication available over-the-counter. Alli would be indicated for use by overweight adults along with a reduced-calorie, low-fat diet. Help and advice on adopting a healthy eating plan will be provided in the alli program.
   Xenical (orlistat 120 mg capsules) will remain available by prescription for obesity management and for those who should be treated under the care of a physician. Xenical is manufactured by Roche and co-promoted in the U.S. by GlaxoSmithKline Consumer Healthcare.

Nonalcoholic Fatty Liver

A double-blind randomized placebo-controlled trial of orlistat 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 orlistat 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 orlistat (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 orlistat 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 orlistat group. Orlistat improves serum ALT levels and steatosis on US in NAFLD patients, however there is the concern of elevated serum glucose and insulin levels.