Drug Interactions between enfortumab vedotin and ivacaftor / lumacaftor

Ivacaftor may increase the blood levels of the active medication in enfortumab vedotin in some patients. This may increase the risk and/or severity of side effects such as nausea; vomiting; diarrhea; loss of appetite; tingling, numbness or burning in the hands and feet; muscle weakness; hyperglycemia (high blood sugar); skin reactions (rash, itching, hair loss); lung problems (trouble breathing, shortness of breath, cough); eye disorders (dry eyes, inflammation of the cornea, blurred vision); and low platelet and white blood cell counts. You may also be more likely to develop bleeding problems or infections due to low 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.

Lumacaftor may reduce the blood levels and effects of enfortumab vedotin. Your doctor may be able to prescribe alternatives that do not interact; or you may need more frequent monitoring to safely use both medications. Contact your doctor if your condition changes or if you have any questions about your treatment. 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.