Drug Interaction Report

Using erythromycin together with ketoconazole can increase the risk of an irregular heart rhythm that may be serious and potentially life-threatening, although it is a relatively 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 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. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or heart palpitations during treatment with these 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.

Switch to professional interaction data

Information for this minor interaction is available on the professional version.

Information for this minor interaction is available on the professional version.

Food decreases the levels of erythromycin in your body. Take erythromycin on an empty stomach at least 30 minutes before or 2 hours after a meal. This will make it easier for your body to absorb the medication. However, some erythromycin products may be taken without regard to meals. Ask your healthcare provider about your particular prescription if you are uncertain of how to take it. Grapefruits and grapefruit juice may increase erythromycin levels but how this may affect you is not known. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.

Switch to professional interaction data

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.

Switch to professional interaction data

Consuming large amounts of certain fruit juices, including grapefruit, orange and apple, may decrease the levels of fexofenadine in your body. Fexofenadine should be taken with water and refrain from drinking large amounts of grapefruit, orange, or apple juice. This will make it easier for your body to absorb the medication.

Switch to professional interaction data

Information for this minor interaction is available on the professional version.