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 quinidine properly.
What might happen:
Your blood levels of quinidine may go up and increase your risk for an irregular heartbeat, which may be life-threatening.
What you should do about this interaction:
Let your healthcare professionals (e.g doctor or pharmacist) know right away that you are taking these medications together. Let your doctor know right away if you notice an irregular heartbeat, palpitations, or onset of dizziness or fainting episodes.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.US Food and Drug Administration (FDA). Drug Development and Drug Interactions: Table of Substrates, Inhibitors and Inducers. Available at: http://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/D rugInteractionsLabeling/ucm093664.htm. Updated 08/05/2011.
2.Viracept (nelfinavir mesylate) US prescribing information. Agouron Pharmaceuticals, Inc. May, 2013.
3.Norvir (ritonavir) US prescribing information. Abbott Laboratories November, 2012.
4.Aptivus (tipranavir) US prescribing information. Boehringer Ingelheim Pharmaceuticals, Inc. February, 2012.
5.Victrelis (boceprevir) US prescribing information. Schering Corporation July, 2014.
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7.Nuedexta (dextromethorphan hydrobromide and quinidine sulfate) US prescribing information. Avanir Pharmaceuticals August, 2011.