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:
Atazanavir may slow down how quickly your body processes irinotecan.
What might happen:
The amount of irinotecan in your blood may increase. This may cause you to have more side effects from your medicine. Possible side effects include but are not limited to diarrhea, difficulty sleeping, dizziness, fever, rash, or vomiting.
What you should do about this interaction:
Contact your healthcare professionals (e.g. doctor or pharmacist) right away about using these medicines together. Your doctor may want to change the dose of your medicine or your medicine. Let your doctor know if you have any side effects from your irinotecan.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.Reyataz (atazanavir sulfate) Australian product information. Bristol-Myers Squibb Pharmaceuticals January 8, 2004.
2.Reyataz (atazanavir sulfate) US prescribing information. Bristol-Myers Squibb Company March, 2015.
3.Camptosar (irinotecan hydrochloride) US prescribing information. Pharmacia & Upjohn Company December, 2014.
4.Phansalkar S, Desai AA, Bell D, Yoshida E, Doole J, Czochanski M, Middleton B, Bates DW. High-priority drug-drug interactions for use in electronic health records. J Am Med Inform Assoc 2012 Sep-Oct; 19(5):735-43.