Xenical (Orlistat) Contraindications and Precautions
- cholestasis
- malabsorption syndrome
- anorexia nervosa
- breast-feeding
- bulimia nervosa
- children
- elderly
- gallbladder disease
- hepatitis
- hypothyroidism
- nephrolithiasis
- obesity
- pregnancy
Orlistat Contraindications and Precautions
Orlistat should not be used in patients who have demonstrated a hypersensitivity reaction to any of the active or inactive ingredients. Rare cases of hypersensitivity reactions have been reported (see Adverse Reactions).
Cholecystokinin stimulates contraction of the gallbladder after its liberation from the upper gastrointestinal mucosa, which is dependent upon the presence of free fatty acids in the intestinal lumen. Postprandial plasma concentrations of cholecystokinin decreased after multiple doses of orlistat in 2 of 4 studies. Although no decrease in gallbladder contraction was demonstrated in normal-weight healthy subjects during a randomized, double-blind, placebo-controlled, crossover study following a single dose of orlistat, the long-term effects on gallstone formation have not been determined. Orlistat is contraindicated for use in individuals with cholestasis, as may be present in cases of gallbladder disease. Very rare cases of elevated hepatic enzymes, increased alkaline phosphatase, and exceptional cases of hepatitis have been reported. No causal relationship or physiopathological mechanism between hepatitis and orlistat therapy has been established.
Orlistat has been shown to decrease nutrient and vitamin absorption. Therefore, orlistat is contraindicated for use in patients with chronic malabsorption syndrome. Because orlistat can interfere with the absorption of fat-soluble vitamins, all patients should take a daily multivitamin that contains vitamins A, D, E, K, and beta-carotene; the supplement should be taken at least 2 hours before or after orlistat (see Drug Interactions).
Orlistat is relatively contraindicated in organic causes of obesity, such as hypothyroidism. Causes of obesity, other than dietary intake, should be ruled out prior to prescribing orlistat.
Since orlistat can produce weight loss, there is a potential for abuse by certain patient populations, including those with anorexia nervosa or bulimia nervosa. These patients should not use orlistat.
Increased levels of urinary oxalate may occur following treatment with orlistat. Use caution in patients with a history of calcium oxalate nephrolithiasis or hyperoxaluria.
Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Orlistat should not be taken by women who are breast-feeding, as it is not known if orlistat is secreted in human milk.
Orlistat is not recommended for use during pregnancy as there are no adequate or well-controlled trials in pregnant women. Animal studies at doses up to 800 mg/kg/day of orlistat showed no teratogenicity or embryotoxicity. However, animal studies are not always predictive of human response.
Use caution in pediatric administration, as the safety and efficacy of orlistat has not been evaluated in children < 12 years of age. According to the manufacturer, use in obese 12 - 16 year old adolescents is supported by studies in adults and additional data from a 54-week safety and efficacy study conducted in obese adolescents.
There were inadequate numbers of patients 65 years of age and older included in clinical trials to determine patient response. Therefore, use with caution in the elderly population.
[ Last revised: 9/15/2005 2:16:00 PM ]
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