Blocks absorption of ingested fat by inhibiting pancreatic lipase.`
A lipase inhibitor.
Can cause unpleasant side effects such as flatulence with discharge, oily spotting and urgency.
Trade names Xenical, Alli
Oral agent.
Bioavailability is negligible.
Protein binding greater than 99%.
Metabolism occurs In the GI tract.
Biological half-life 1 to 2 hours.
Excretion by fecal route.
Its primary function is preventing the absorption of fats from the human diet by acting as a lipase inhibitor, thereby reducing caloric intake.
As a result, some fat cannot be absorbed from the gut and is excreted in the feces instead of being metabolically digested and absorbed, sometimes causing oily anal leakage.
It is intended for use in conjunction with a reduced-calorie diet.
Refers to the saturated derivative of lipstatin, a potent natural inhibitor of pancreatic lipases isolated from the bacterium Streptomyces toxytricini.
The effectiveness in promoting weight loss is definite but modest.
People given orlistat in addition to lifestyle modifications, such as diet and exercise, lose about 2–3 kilograms (4.4–6.6 lb) more than those not taking the drug over the course of a year.
Modestly reduces blood pressure and appears to prevent the onset of type 2 diabetes,
Reduces the incidence of diabetes by nearly 40% in obese people.
Associated with severe gastrointestinal side effects which can include steatorrhea.
Orlistat gastrointestinal adverse effects are frequent, including flatulence, steatorrhea , and diarrhea, and may cause malabsorption of fat soluble vitamins.
Gastrointestinal side effects decrease with time.
Available OTC.
Used for the treatment of obesity.
Between 35.5% and 54.8% of subjects achieved a 5% or greater decrease in body mass, and between 16.4% and 24.8% achieved at least a 10% decrease in body fat.
Associated with excessive flatus due to unabsorbed fats reaching the large intestine), fecal incontinence and frequent or urgent bowel movements.
Foods with high fat content should be avoided, and patients should follow a low-fat, reduced-calorie diet.
Oily stools and flatulence can be controlled by reducing the dietary fat content to 15 grams per meal.
Treatment involves aversion therapy, encouraging the user to associate eating fat with unpleasant treatment effects.
Side effects are most severe when beginning therapy and may decrease in frequency with time.
In the XENDOS study, 36% of people had gastrointestinal adverse effects during their fourth year of taking orlistat, whereas 91% of study subjects had experienced at least one GI-related side effect during the first year of treatment.
Liver injury has been reported rarely.
The rate of acute kidney injury is more than triple that of non-users possibly due to excessive oxalate absorption from the gut and its subsequent deposition in the kidney.
Excessive oxalate absorption being a known consequence of fat malabsorption.
Absorption of fat-soluble vitamins and other fat-soluble nutrients is inhibited by the use of orlistat, so that a multivitamin tablet containing vitamins A, D, E, K, and beta-carotene should be taken once a day, at bedtime, when using orlistat.
Orlistat may reduce plasma levels of cyclosporine, and should therefore not be administered concomitantly.
Orlistat can also impair absorption of amiodarone, and may reduce the absorption of antiretroviral HIV medications.
Works by inhibiting gastric and pancreatic lipases, the enzymes that break down triglycerides in the intestine.
When lipase activity is blocked, triglycerides from the diet are not hydrolyzed into absorbable free fatty acids, and instead are excreted unchanged.
Only trace amounts of orlistat are absorbed systemically.
Its primary effect is local lipase inhibition within the GI tract after an oral dose.
Its primary route of elimination is through the feces.
The standard dose of 120 mg three times daily before meals, prevents approximately 30% of dietary fat from being absorbed.
It prevents about 25% at the standard over-the-counter dose of 60 mg.
Higher doses do not produce more potent effects.
Marketed under the name alli, is the first weight loss drug officially sanctioned by the U.S. government for over-the-counter use.
Alli is sold as 60 mg capsules—half the dosage of prescription orlistat.