Drug Interaction Report

Elacestrant may increase the blood levels of afatinib. You may be more likely to experience side effects such as mouth sores; diarrhea, which can lead to dehydration and kidney problems if severe; skin reactions such as dryness, redness, rash, acne, peeling, or blistering; lung disorders causing breathing difficulty, shortness of breath, cough, and fever; eye problems resulting in eye pain, swelling, redness, tearing, light sensitivity, blurred vision, and other vision disturbances; liver damage indicated by symptoms such as fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, abdominal pain, dark colored urine, light colored stools, and/or yellowing of the skin or eyes; and heart problems resulting in tiredness, shortness of breath (either at rest or during activities), palpitation, water retention, sudden weight gain, and swelling of the feet, ankles, or legs. Contact your doctor immediately if you develop these or other unusual symptoms. You may need a dose adjustment or more frequent monitoring by your doctor 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.

Elacestrant should be taken with food at approximately the same time each day. Grapefruit, grapefruit juice, and supplements that contain grapefruit, however, may increase the blood levels of elacestrant, which may increase the risk of side effects such as muscle pain, nausea, increased cholesterol, increased liver enzymes, fatigue, decreased hemoglobin, and vomiting. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact. 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 may reduce the absorption of afatinib, which may lead to lower blood levels of the medication and possibly reduced effectiveness. You should take afatinib at least 1 hour before or 2 hours after a meal.