Drug Interaction Report

Lapatinib may increase the blood levels of lomitapide. You may be more likely to experience side effects such as diarrhea, nausea, vomiting, stomach pain or discomfort, indigestion, gas, constipation, and liver damage. 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 by your doctor to safely use both medications. Avoid or limit the use of alcohol to no more than one drink per day during treatment with lomitapide, and seek immediate medical attention if you develop signs and symptoms of liver damage such as 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 yellowing of the skin or eyes. 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.

Taking lomitapide with food may increase gastrointestinal side effects such as diarrhea, nausea, vomiting, stomach pain or discomfort, constipation, indigestion, and gas. The absorption of any other oral medication you may take can be affected if you develop diarrhea or vomiting. To reduce the risk of gastrointestinal intolerance, lomitapide should be taken once daily with a glass of water, without food, at least 2 hours after the evening meal. You should also follow a low-fat diet (<20% of total calories from fat) during treatment with lomitapide, and avoid the consumption of grapefruit or grapefruit juice. Since lomitapide may cause injury to the liver, you should have no more than one alcoholic drink per day. Call your doctor immediately if you have 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, 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.

Take lapatinib on an empty stomach 1 hour before or 1 hour after a meal unless otherwise directed by your doctor. This will make it easier for your body to absorb the medication. The lapatinib dose is administered once daily and should not be divided. The usual dose of lapatinib is equal to 5 tablets. You may swallow each tablet one at a time, but take the entire lapatinib dose at the same time each day. If you are receiving therapy with lapatinib you should be advised to avoid grapefruits and grapefruit juice. Grapefruit can raise the levels of lapatinib in your body and lead to dangerous side effects.