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tamoxifen

Interactions

Anastrozole; Letrozole/Tamoxifen

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:

Severe. These medicines may interact and cause very harmful effects and are usually not taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Tamoxifen may speed up how quickly your liver processes anastrozole and letrozole.

What might happen:

The beneficial effects of anastrozole and letrozole may decrease.

What you should do about this interaction:

Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together.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.

References:

1.Arimidex (anastrozole) US prescribing information. AstraZeneca Pharmaceuticals LP April, 2011.

2.Dowsett M, Pfister C, Johnston SR, Miles DW, Houston SJ, Verbeek JA, Gundacker H, Sioufi A, Smith IE. Impact of tamoxifen on the pharmacokinetics and endocrine effects of the aromatase inhibitor letrozole in postmenopausal women with breast cancer. Clin Cancer Res 1999 Sep;5(9):2338-43.

3.Nolvadex (tamoxifen citrate) US prescribing information. AstraZeneca Pharmaceuticals LP March, 2006.

4.Weiss L. Personnal communication. Novartis Pharmaceuticals Corporation January 3, 2002.

5.Femara (letrozole) US prescribing information. Novartis Pharmaceuticals Corporation December, 2011.

6.Ingle JN, Suman VJ, Johnson PA, Krook JE, Mailliard JA, Wheeler RH, Loprinzi CL, Perez EA, Jordan VC, Dowsett M. Evaluation of tamoxifen plus letrozole with assessment of pharmacokinetic interaction in postmenopausal women with metastatic breast cancer. Clin Cancer Res 1999 Jul;5(7):1642-9.

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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