From the Guidelines
Orlistat (Xenical) is a recommended medication for weight loss in obese patients with a BMI of 30 or higher, as it can produce modest weight loss of approximately 5-10% of initial body weight over 6-12 months when combined with diet and exercise, as shown in a recent study 1. The standard dosage of orlistat is 120 mg taken three times daily with meals containing fat. This lipase inhibitor works by blocking about 30% of dietary fat absorption in the intestines. Some key points to consider when using orlistat include:
- Side effects primarily involve the gastrointestinal system, including oily spotting, flatulence with discharge, fecal urgency, and fatty stools, which typically occur when dietary fat intake exceeds recommended levels 1.
- To minimize these effects, patients should follow a reduced-calorie diet with fat comprising no more than 30% of total calories, distribute fat intake evenly across meals, and take a daily multivitamin at least 2 hours before or after orlistat to prevent potential deficiencies in fat-soluble vitamins (A, D, E, and K) 1.
- Orlistat is most effective as part of a comprehensive weight management program that includes dietary changes, increased physical activity, and behavioral modifications, as recommended by the USPSTF 1.
- Regular monitoring by healthcare providers is recommended to assess progress and manage any side effects, ensuring the safe and effective use of orlistat for weight loss in obese patients.
From the FDA Drug Label
for overweight adults 18 years and older: take 1 capsule with each meal containing fat do not take more than 3 capsules daily use with a reduced-calorie, low-fat diet and exercise program until you reach your weight loss goal Most weight loss occurs in the first 6 months. orlistat works by preventing the absorption of some of the fat you eat. for every 5 pounds you lose from diet alone, orlistat can help you lose 2-3 pounds more.
The role of orlistat (Xenical) in weight loss for obese patients with a body mass index (BMI) of 30 or higher is to assist in losing weight when used in conjunction with a reduced-calorie, low-fat diet and exercise program.
- Key points:
From the Research
Role of Orlistat in Weight Loss
Orlistat, also known as Xenical, plays a significant role in weight loss for obese patients with a body mass index (BMI) of 30 or higher. The drug works by inhibiting lipases in the gastrointestinal tract, preventing the absorption of approximately 30% of dietary fat 3.
Mechanism of Action and Efficacy
The optimal dose of orlistat is 120 mg three times daily, taken with each main meal 3. Studies have shown that orlistat, in conjunction with a hypocaloric diet, enables weight reduction of 7.9 to 10.2% in obese non-diabetic individuals 3. In patients with type 2 diabetes, orlistat has been shown to improve glycaemic control, enabling dosages of antidiabetic drugs to be reduced 3.
Benefits and Side Effects
The use of orlistat has been associated with several benefits, including:
- Improved lipid profiles in non-diabetic obese patients, reducing levels of total cholesterol and low density lipoprotein cholesterol 3
- Significant improvements in glycaemic control in patients with type 2 diabetes 3
- Modest improvements in systolic and diastolic blood pressure, low-density lipoprotein (LDL) cholesterol, glycemic parameters, and progression to diabetes in people with impaired glucose tolerance 4 However, orlistat is also associated with several side effects, including:
- Gastrointestinal side effects such as oily faecal spotting, flatus with discharge, faecal urgency, and oily stool 3, 5
- Decreased absorption of fat-soluble vitamins, which can be mitigated by taking a daily multiple vitamin 6
Dosage and Tolerability
Orlistat is available in two doses: 120 mg and 60 mg. The 120 mg dose is more effective for weight loss, but is also associated with more gastrointestinal side effects 7. The 60 mg dose, which is available over-the-counter, has ~85% of the efficacy of the 120 mg dose for weight loss and is better tolerated 7. Long-term tolerability data have shown that orlistat is generally well tolerated, with most side effects diminishing over time 3, 5.