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Interactions

Estrogens/Grapefruit Juice Interaction

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

Medical warning:

Important. Possible changes in your diet, medicine, or dosage should be discussed with your doctor or pharmacist.

How the interaction occurs:

Grapefruit juice decreases the ability of the gut to process estrogens.

What might happen:

The level of this drug can increase in your blood. This can lead to spotting or bleeding, nausea, vomiting and breast tenderness.

What you should do about this interaction:

It is best to avoid grapefruit or grapefruit juice while on this medication.Tell your doctor or pharmacist if you experience nausea, vomiting, spotting or bleeding, and breast tenderness.Contact your healthcare professional (e.g., doctor or pharmacist) for more information.Your healthcare professionals may be aware of this interaction and may be monitoring you for it. Do not start, stop, or change your medicine or diet before checking with them first.

References:

1.Guengerich FP. Oxidation of 17 alpha-ethynylestradiol by human liver cytochrome P-450. Mol Pharmacol 1988 May;33(5):500-8.

2.Ball SE, Forrester LM, Wolf CR, Back DJ. Differences in the cytochrome P-450 isoenzymes involved in the 2-hydroxylation of oestradiol and 17 alpha-ethinyloestradiol. Relative activities of rat and human liver enzymes. Biochem J 1990 Apr 1;267(1):221-6.

3.Miniscalco A, Lundahl J, Regardh CG, Edgar B, Eriksson UG. Inhibition of dihydropyridine metabolism in rat and human liver microsomes by flavonoids found in grapefruit juice. J Pharmacol Exp Ther 1992 Jun;261(3):1195-9.

4.Schubert W, Cullberg G, Edgar B, Hedner T. Inhibition of 17 beta-estradiol metabolism by grapefruit juice in ovariectomized women. Maturitas 1994 Dec;20(2-3):155-63.

5.Schubert W, Eriksson U, Edgar B, Cullberg G, Hedner T. Flavonoids in grapefruit juice inhibit the in vitro hepatic metabolism of 17 beta-estradiol. Eur J Drug Metab Pharmacokinet 1995 Jul-Sep;20(3):219-24.

6.Fingerova H, Oborna I, Petrova P, Budikova M, Jezdinsky J. Does grapefruit juice increase the bioavailability of orally administered sex steroids?. Ceska Gynekol 2003 Mar;68(2):117-21.

7.Premarin (conjugated estrogen tablets, USP) US prescribing information. Wyeth Pharmaceuticals Inc. October, 2011.

Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, expect as may be authorized by the applicable terms of use.

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.

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