Orlistat/Fat Soluble Vitamins Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Orlistat interferes with the absorption of the fat soluble vitamins.

What might happen:

You might not be able to absorb enough fat soluble vitamins.

What you should do about this interaction:

Tell your doctor you are taking orlistat. He may want you to take additional vitamin supplementation or may advise alternate therapy. If your doctor instructs you to take a vitamin supplement, take it at least 2 hours before or 2 hours after your orlistat.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

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  • 2.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 Jul;36(7):647-53.
  • 3.Xenical (orlistat) Australian rescribing information. Roche May 30, 2002.
  • 4.Xenical (orlistat) US prescribing information. Roche Laboratories, Inc. November, 2022.
  • 5.McDuffie JR, Calis KA, Booth SL, Uwaifo GI, Yanovski JA. Effects of orlistat on fat-soluble vitamins in obese adolescents. Pharmacotherapy 2002 Jul;22(7):814-22.
  • 6.Alli (orlistat) US prescribing information. GSK Consumer Healthcare May, 2017.

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.