Orlistat

Aka: Orlistat, Xenical

1. Indication for Obesity Management
   1. Body Mass Index over 30 kg/m2
   2. Body Mass Index over 27 kg/m2 with comorbidity
      1. Diabetes Mellitus
      2. Hypertension
      3. Dyslipidemia
2. Mechanism
   1. Pentanoic acid ester binds gastric, pancreatic Lipase
   2. Lipase Inhibitor (Blocks Fat absorption)
      1. Decreased Triglyceride absorption
      2. Decreased Cholesterol absorption
3. Pharmacokinetics
   1. Minimal systemic absorption
4. Efficacy
   1. Combined results of two large Placebo controlled trials
      1. Year one
         1. Orlistat: 9-10 kg loss (10% of baseline weight)
         2. Placebo: 6 kg (6% of baseline weight)
      2. Year two
         1. Orlistat: 1.5-3 kg regained weight
         2. Placebo: 4-6 kg regained weight
   2. References
      1. Sjostrom (1998) Lancet 352:167
      2. Davidson (1999) JAMA 281:235
5. Adverse effects
   1. Gastrointestinal side effects (40%)
      1. Flatus with discharge
      2. Oily stool with spotting
      3. Fecal urgency
      4. Fecal Incontinence
      5. Abdominal Pain
   2. Fat soluble Carotenoid (fruit, vegetable) malabsorption
   3. Fat soluble vitamin malabsorption: No supplement needed
      1. Vitamin A
      2. Vitamin D
      3. Vitamin E
      4. Vitamin K
6. Drug Interactions
   1. Does not interfere with absorption of other medications
      1. Coumadin
      2. Oral Contraceptives
      3. Antihypertensives
7. Dosing
   1. Take three times daily with each meal containing fat
   2. Prescription dose: 120 mg orally three times daily
   3. OTC dose: 60 mg orally three time daily
8. Precautions
   1. Avoid fat-soluble vitamins within 2 hours of Orlistat
   2. Maintain Dietary Fat intake <30% of calories
9. References
   1. (1999) Med Lett Drugs Ther 41(1055):55-6