Skip to content
My WebMD Sign In, Sign Up
nelfinavir

Interactions

Protease Inhibitors/Astemizole; Terfenadine

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:

When these two medicines are taken together, your body may not process your antihistamine properly.

What might happen:

The blood levels of your antihistamine may increase and cause an irregular heartbeat.

What you should do about this interaction:

Contact your healthcare professionals (e.g. doctor or pharmacist) as soon as possible about taking these two medicines together. They may already be aware of this interaction and may be monitoring you for it. It may be necessary to change you to a different antihistamine. Do not start, stop, or change the dosage of any medicine before checking with them first.

References:

1.Agenerase (amprenavir) US prescribing information. Glaxo Wellcome, Inc. April, 1999.

2.Prezista (darunavir) US prescribing information. Tibotec Inc. June, 2006.

3.Kaletra (lopinavir/ritonavir tablets) US prescribing information. Abbott Laboratories September, 2007.

4.Norvir (ritonavir) US prescribing information. Abbott Laboratories March, 1997.

5.Aptivus (tipranavir) US prescribing information. Boehringer Ingelheim Pharmaceuticals, Inc. June, 2007.

6.Crixivan (indinavir sulfate) US prescribing information. Merck & Co., Inc. January, 2004.

7.Viracept (nelfinavir mesylate) US prescribing information. Agouron Pharmaceuticals, Inc. March, 1997.

8.Fortovase (saquinavir) US prescribing information. Roche Laboratories, Inc. December, 2004.

9.Invirase (saquinavir mesylate) US prescribing information. Roche Laboratories, Inc. July, 2007.

10.Seldane (terfenadine) US prescribing information. Hoechst-Marion Roussel September, 1997.

11.Allegra (fexofenadine hydrochloride) US prescribing information. Sanofi-Aventis U.S. LLC October, 2006.

12.Claritin (loratadine) US prescribing information. Schering-Plough Corporation January, 1997.

13.Lexiva (fosamprenavir calcium) US prescribing information. GlaxoSmithKline October, 2003.

14.Drew BJ, Ackerman MJ, Funk M, Gibler WB, Kligfield P, Menon V, Philippides GJ, Roden DM, Zareba W. Prevention of torsade de pointes in hospital settings: a scientific statement from the American Heart Association and the American College of Cardiology Foundation. J Am Coll Cardiol 2010 Mar 2;55(9):934-47.

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.

More about Drugs and Medications

Newsletters

Subscribe to free WebMD newsletters.

  • WebMD Daily

    WebMD Daily

    Subscribe to the WebMD Daily, and you'll get today's top health news and trending topics, and the latest and best information from WebMD.

  • Men's Health

    Men's Health

    Subscribe to the Men's Health newsletter for the latest on disease prevention, fitness, sex, nutrition, and more from WebMD.

  • Women's Health

    Women's Health

    Subscribe to the Women's Health newsletter for the latest on disease prevention, fitness, sex, diet, anti-aging, and more from WebMD.

By clicking Submit, I agree to the WebMD Terms & Conditions & Privacy Policy

URAC: Accredited Health Web Site HONcode Seal AdChoices