Drug Interactions between entrectinib and lopinavir / ritonavir

Ritonavir may significantly increase the blood levels of entrectinib. This may increase the risk and/or severity of side effects such as dizziness; confusion; hallucinations; problems with concentration, attention, thinking, and memory; mood changes; insomnia; drowsiness; liver problems; increased uric acid levels in the blood (hyperuricemia); congestive heart failure; fluid retention and swelling; changes in electrical activity of the heart (a condition known as QT prolongation, which may lead to irregular heart rhythm that can be life-threatening); vision problems; and low red or white blood cell counts. Talk to your doctor if you have any questions or concerns. 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. 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.

Using entrectinib together with lopinavir can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a rare side effect. You may be more susceptible if you have a heart condition called congenital long QT syndrome, other cardiac diseases, conduction abnormalities, or electrolyte disturbances (for example, magnesium or potassium loss due to severe or prolonged diarrhea or vomiting). 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 seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with these medications, whether together or alone. 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.