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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:

Ribavirin may affect how your body processes azathioprine.

What might happen:

The amount of metabolites of azathioprine in your blood may increase and decrease your bone marrow's ability to make certain blood cells.

What you should do about this interaction:

Make sure your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines together. Your doctor may want to check the amount of certain cells in your blood more often when you first start taking these medicines together or if the dose of one or both are changed. Let your doctor know if you feel tired, dizzy, or weak; develop chest pain or shortness of breath; or bruising or unusual bleeding.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.


1.Copegus (ribavirin) US prescribing information. Roche Laboratories, Inc. August, 2015.

2.Imuran (azathioprine) US prescribing information. Prometheus Laboratories Inc. February, 2014.

3.Chaparro M, Trapero-Marugan M, Moreno-Otero R, Gisbert JP. Azathioprine plus ribavirin treatment and pancytopenia. Aliment Pharmacol Ther 2009 Nov 1;30(9):962-3.

4.Peyrin-Biroulet L, Cadranel JF, Nousbaum JB, Oussalah A, Seddik M, Canva V, Cortot A, Sogni P, Gueant JL, Bigard MA, Roblin X, Bronowicki JP. Interaction of ribavirin with azathioprine metabolism potentially induces myelosuppression. Aliment Pharmacol Ther 2008 Oct 15;28(8):984-93.

5.Thevenot T, Mathurin P, Moussalli J, Perrin M, Plassart F, Blot C, Opolon P, Poynard T. Effects of cirrhosis, interferon and azathioprine on adverse events in patients with chronic hepatitis C treated with ribavirin. J Viral Hepat 1997 Jul;4(4):243-53.

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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