Drug Interactions between atazanavir / cobicistat and olaparib

Consumer information for this interaction is not currently available.

GENERALLY AVOID: Coadministration with potent inhibitors of CYP450 3A4 may significantly increase the plasma concentrations of olaparib, which is primarily metabolized by the isoenzyme. In a drug interaction study with 57 patients, mean olaparib peak plasma concentration (Cmax) and systemic exposure (AUC) increased by approximately 1.4- and 2.7-fold, respectively, during coadministration with the potent CYP450 3A4 inhibitor itraconazole. Increased exposure to olaparib may increase the risk of adverse effects such as hematologic toxicity, nausea, vomiting, diarrhea, anorexia, dyspepsia, and abdominal pain or discomfort.

MANAGEMENT: Concomitant use of olaparib with potent CYP450 3A4 inhibitors should be avoided whenever possible. Some authorities recommend avoiding concomitant use of olaparib during and for 2 weeks after treatment with itraconazole. If coadministration is required, the olaparib dosage should be reduced to 100 mg twice a day. Once the CYP450 3A4 inhibitor has been discontinued for 3 to 5 elimination half-lives, the usual olaparib dose should be resumed.

Cobicistat may significantly increase the blood levels of olaparib. This can increase the risk and/or severity of side effects such as nausea, vomiting, diarrhea, indigestion, loss of appetite, abdominal pain or discomfort, lung problems, and impaired bone marrow function resulting in low numbers of different types of blood cells. You may also be more likely to develop anemia, bleeding problems, or infections due to low blood cell counts. Talk to your doctor if you have any questions or concerns. Your doctor may already be aware of the risks, but has determined that this is the best course of treatment for you and has taken appropriate precautions and is monitoring you closely for any potential complications. You should contact your doctor if you develop paleness, fatigue, dizziness, fainting, unusual bruising or bleeding, fever, chills, diarrhea, sore throat, muscle aches, shortness of breath, blood in phlegm, weight loss, red or inflamed skin, body sores, and pain or burning during urination. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.