Orlistat
Drug Information
Orlistat is used for Reference obesity management, including weight loss and weight maintenance, in association with a low-calorie diet.
Common brand names:
Alli, XenicalSummary of Interactions with Vitamins, Herbs, & Foods
Replenish Depleted Nutrients
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Beta-Carotene
One well-controlled study showed that taking orlistat greatly reduces the absorption of beta-carotene.1 Therefore, individuals taking orlistat for long periods of time should probably supplement with beta-carotene.
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Vitamin A
In one well-controlled study, taking orlistat for six months resulted in reduced blood levels of vitamins A and D, though levels for most individuals remained within the normal range. However, a few people developed levels low enough to require supplementation.2 Other studies have shown that taking orlistat had no affect on blood vitamin A levels.3 , 4 Although additional research is needed, the current evidence suggests that individuals taking orlistat for more than six months should supplement with vitamins A and D.
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Vitamin D
In one well-controlled study, taking orlistat for six months resulted in reduced blood levels of vitamins A and D, though levels for most individuals remained within the normal range. However, a few people developed levels low enough to require supplementation.5 Other studies have shown that taking orlistat had no affect on blood vitamin A levels.6 , 7 Although additional research is needed, the current evidence suggests that individuals taking orlistat for more than six months should supplement with vitamins A and D.
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Vitamin E
Taking orlistat dramatically reduces the absorption of vitamin E,8 which might result in deficiency symptoms. Therefore, people taking orlistat for long periods of time should supplement with vitamin E.
Reduce Side Effects
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Psyllium
In a group of obese women taking orlistat three times per day, ingestion of 6 grams of psyllium with each dose of orlistat significantly reduced the gastrointestinal side effects of the drug.9
Support Medicine
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none
Reduces Effectiveness
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none
Potential Negative Interaction
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none
Explanation Required
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none
References
1. Zhi J, Melia AT, Koss-Twardy SG, et al. The effect of orlistat, an inhibitor of dietary fat absorption, on the pharmacokinetics of beta-carotene in healthy volunteers. J Clin Pharmacol 1996;36:152–9.
2. Van Gaal LF, Broom JI, Enzi G, Toplak H. Efficacy and tolerability of orlistat in the treatment of obesity: a 6-month dose ranging study. Orlistat Dose-Ranging Study Group. Eur J Clin Pharmacol 1998;54:125–32.
3. Melia AT, Koss-Twardy SG, Zhi J. The effect of orlistat, an inhibitor of dietary fat absorption, on the absorption of vitamins A and E in healthy volunteers. J Clin Pharmacol 1996;36:647–53.
4. James WP, Aveell A, Broom J, Whitehead J. A one-year trial to assess the value of orlistat in the management of obesity. Int J Obes Relat Metab Disord 1997;21 Suppl 3:S24–30.
5. Van Gaal LF, Broom JI, Enzi G, Toplak H. Efficacy and tolerability of orlistat in the treatment of obesity: a 6-month dose ranging study. Orlistat Dose-Ranging Study Group. Eur J Clin Pharmacol 1998;54:125–32.
6. Melia AT, Koss-Twardy SG, Zhi J. The effect of orlistat, an inhibitor of dietary fat absorption, on the absorption of vitamins A and E in healthy volunteers. J Clin Pharmacol 1996;36:647–53.
7. James WP, Aveell A, Broom J, Whitehead J. A one-year trial to assess the value of orlistat in the management of obesity. Int J Obes Relat Metab Disord 1997;21 Suppl 3:S24–30.
8. Sifton DW, ed. Physicians’ Desk Reference. Montvale, NJ: Medical Economics Company, Inc., 2000, 2693–6.
9. Cavaliere H, Floriano I, Medeiros-Neto G. Gastrointestinal side effects of orlistat may be prevented by concomitant prescription of natural fibers (psyllium mucilloid). Int J Obes Relat Metab Disord 2001;25:1095–9.
Last Review: 11-07-2012
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