Drug Interaction Report

Using saquinavir together with ritonavir may increase the effects of saquinavir. Contact your doctor if you experience increased urination or extreme thirst, easy bruising or bleeding, fever, chills, cough, nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes). If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both 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.

Saquinavir may increase the blood levels of paritaprevir, one of the components of your hepatitis C medication. This may increase the risk and/or severity of side effects such as liver problems and excessive bilirubin levels in the blood, which in severe cases can lead to seizures and brain damage. However, in clinical trials, bilirubin elevations usually resolved with continued treatment. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact. You should seek immediate medical attention if you develop fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, dark colored urine, light colored stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. 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 saquinavir in your body. Saquinavir should be taken with meals or within 2 hours after eating. This will make it easier for your body to absorb the medication. Grapefruit can raise the levels of saquinavir in your body. Discuss the use of grapefruit products with your doctor. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.

Ritonavir should be taken with food to lessen gastrointestinal side effects. It is important that you take this medication exactly as prescribed by your doctor. Do not change your treatment or stop treatment without first talking to your doctor.

Food significantly increases the absorption of paritaprevir. You should take each dose of paritaprevir with a meal. Taking it on an empty stomach may lead to inadequate blood levels and reduced effectiveness of 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:

• saquinavir
• Viekira XR (dasabuvir / ombitasvir / paritaprevir / ritonavir)

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.