Orlistat is indicated for the treatment of obesity in conjunction with a low-calorie diet. It is also used to maintain weight loss in overweight individuals who have already achieved weight loss through diet and exercise.

Obesity

The recommended dose of Orlistat is 120 mg three times daily with meals. It should be taken orally, swallowed whole with water. The dosage for children below the age of 12 has not been established. Orlistat is not recommended for use in elderly patients above the age of 65 years.

The most common adverse reactions associated with Orlistat are gastrointestinal in nature and include-

• oily spotting
• flatus with discharge
• fecal urgency
• fatty/oily stool
• oily evacuation
• increased defecation

Other adverse reactions may include abdominal pain, nausea, vomiting, headache, back pain, and upper respiratory tract infection.

Flattus with discharge

Fecal Urgency

Steatorhhea (oily stool)

• Organic causes of obesity (eg, hypothyroidism) should be excluded before prescribing Orlistat.
• Patients should be advised to adhere to dietary guidelines. Gastrointestinal events may increase when Orlistat is taken with a diet high in fat (>30% total daily calories from fat). The daily intake of fat should be distributed over three main meals. If Orlistat is taken with any one meal very high in fat, the possibility of gastrointestinal effects increases.
• Patients should be strongly encouraged to take a multivitamin supplement that contains fat-soluble vitamins to ensure adequate nutrition because Orlistat has been shown to reduce the absorption of some fat-soluble vitamins and beta-carotene. In addition, the levels of vitamin D and beta-carotene may be low in obese patients compared with nonobese subjects. The supplement should be taken once a day at least 2 hours before or after the administration of Orlistat, such as at bedtime. 
• Some patients may develop increased levels of urinary oxalate following treatment with Orlistat. Caution should be exercised when prescribing Orlistat to patients with a history of hyperoxaluria or calcium oxalate nephrolithiasis. 
• As with any weight-loss agent, the potential exists for misuse of Orlistat in inappropriate patient populations (eg, patients with anorexia nervosa or bulimia).