Drug Interactions between ketoconazole and Tykerb

You should avoid the use of alcohol while being treated with ketoconazole. Ketoconazole may cause liver damage and using it with alcohol or products containing alcohol may increase that risk. In addition, consumption of alcoholic beverages or products containing alcohol during treatment with ketoconazole may trigger a disulfiram-like reaction in some patients, with unpleasant symptoms such as flushing, palpitations, and nausea. Ketoconazole may be taken with or without food. You should avoid consumption of grapefruit, grapefruit juice, or any supplements that contain grapefruit extract during treatment with ketoconazole unless directed otherwise by your doctor. Grapefruit juice may increase the blood levels of ketoconazole. This may increase the risk and/or severity of side effects and liver problems. You should seek immediate medical attention if you develop signs and symptoms of liver damage during treatment with ketoconazole, such as 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. Talk to your doctor if you have any questions or concerns. 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.