Drug Interaction Report

Nelfinavir may increase the blood levels and effects of atazanavir. This may increase the risk and/or severity of side effects such as jaundice, kidney stones, gallstones, high blood sugar, diabetes, and irregular heartbeat. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if you develop yellowing of the skin or eyes, pain in your side or lower back, painful urination, blood in your urine, abdominal pain or tenderness, or sudden dizziness, lightheadedness, fainting, or a slow heart rate during treatment with these medications. 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.

Cobicistat is a medication used to boost the effects of some medications that treat HIV infection. However, using cobicistat together with other HIV medications, such as nelfinavir, may alter the blood levels and effects of both medications. Using nelfinavir with cobicistat may reduce or increase blood levels of cobicistat. Reduced blood levels of cobicistat may make cobicistat less effective and may cause overall HIV treatment to be less effective. Cobicistat may increase blood levels of nelfinavir which may increase the risk of side effects. Talk to your doctor or pharmacist if you have any questions on how to use these medications properly. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. Contact your doctor if your condition changes or you experience increased side effects. 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.

Food can enhance the levels of atazanavir in your body. To ensure maximal oral absorption, atazanavir should be administered with or immediately after a meal. This will make it easier for your body to absorb the medication.

The recommended maximum number of medicines in the 'protease inhibitors' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'protease inhibitors' category:

• atazanavir / cobicistat
• nelfinavir

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.