Action

Inhibits absorption of dietary fats in stomach and small intestine

Availability

Capsules: 60 mg (over-the-counter drug), 120 mg

Indications and dosages

➣ Obesity management (in conjunction with reduced-calorie diet); to reduce risk of regaining after weight loss

Adults: 120 mg (Xenical) P.O. t.i.d. with each main meal containing fat (during or up to 1 hour after the meal)

➣ Weight loss in overweight adults (in conjunction with reduced-calorie and low-fat diet)

Adults ages 18 and older: 60 mg (Alli) P.O. t.i.d. with each meal containing fat

Contraindications

• Hypersensitivity to drug or its components

• Chronic malabsorption syndrome or cholestasis

• Patients who have had organ transplant or are taking drugs to reduce organ rejection (such as cyclosporine), patients with known problems absorbing food (Alli)

• Pregnancy

Precautions

Use cautiously in:

• hypothyroidism, nephrolithiasis, diabetes mellitus, clinically significant GI disease, fat-soluble vitamin deficiencies

• history of bulimia or anorexia nervosa

• breastfeeding patients

• children.

Administration

• Know that organic causes of obesity should be ruled out before therapy starts.

• Give three times daily with meal containing fat (Alli) or up to 1 hour after a meal (Xenical).

• If patient misses a meal or eats a fat-free meal, omit dose.

• Know that orlistat therapy is frequently combined with psychotherapy.

Adverse reactions

CNS: Xenical: dizziness, headache, fatigue, insomnia, depression, anxiety

EENT: Xenical: ear, nose, and throat symptoms

GI: fecal urgency, flatus with discharge, oily or increased bowel movements, oily spotting, fecal incontinence

GU: Xenical: urinary tract infection (UTI), vaginitis, menstrual irregularities

Hepatic: severe liver injury (rare)

Musculoskeletal: Xenical: back pain, arthritis, myalgia, tendinitis

Respiratory: Xenical: upper or lower respiratory infection

Skin: Xenical: dry skin, rash

Other: Xenical: dental pain, tooth disorder, influenza

Interactions

Drug-drug. Beta-carotene, fat-soluble vitamins: reduced vitamin absorption

Cyclosporine: reduced cyclosporine blood level (Xenical)

Pravastatin: increased lipid-lowering effects (Xenical)

Warfarin: altered coagulation parameters

Patient monitoring

See Monitor hepatic function closely. If liver injury is suspected, discontinue drug immediately and continue to monitor liver function tests.

• Watch for signs and symptoms of UTI, respiratory infection, and EENT disorders.

• Monitor patient for weight loss.

• Evaluate patient's diet for appropriate caloric intake.

• Be aware that patient may develop an elevated urinary oxalate level. Monitor renal function in patients at risk for renal insufficiency.

Patient teaching

• Instruct patient to take with meals as directed. Tell him he may omit a dose if he misses a meal or eats a fat-free meal.

• Advise patient to consume reduced-calorie diet and to spread daily fat intake over three main meals.

• Inform patient that drug predisposes him to EENT, respiratory, and urinary infections. Instruct him to promptly report signs and symptoms.

See Instruct patient to report signs or symptoms of hepatic dysfunction (anorexia, pruritus, jaundice, dark urine, light-colored stools, or right upper quadrant pain).

• Tell patient about common adverse GI reactions, including problems controlling bowel movements. If significant GI upset occurs, encourage him to consult prescriber about taking psyllium at bedtime or with each dose.

• Advise patient to ask prescriber if he should take a daily multivitamin containing vitamins A, D, E, K, and beta-carotene at least 2 hours before or after taking drug.

• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs mentioned above.