Drug Interactions between fedratinib and sonidegib

Sonidegib should be taken on an empty stomach, at least 1 hour before or 2 hours after a meal. The presence of food can significantly increase the absorption of sonidegib into the blood stream. This may increase side effects such as muscle spasms, muscle pain, muscle weakness, fatigue, nausea, vomiting, diarrhea, loss of appetite, weight loss, hair loss, itching, and taste abnormalities. You may also have an increased risk of developing a rare but serious condition called rhabdomyolysis that involves the breakdown of skeletal muscle tissue. In some cases, rhabdomyolysis can cause kidney damage and even death. Let your doctor know immediately if you have unexplained muscle pain, tenderness, or weakness during treatment with sonidegib, especially if these symptoms are accompanied by fever or dark colored urine. Grapefruit juice may also increase the blood levels of sonidegib and should be avoided. Talk to your doctor or pharmacist if you have any questions or concerns.

Grapefruit juice can increase the blood levels of fedratinib. This may increase the risk of serious side effects such as Wernicke's encephalopathy, a potentially fatal condition of the brain associated with thiamine (vitamin B1) deficiency; low blood cell counts, which can lead to anemia, bleeding, and infections; severe diarrhea, nausea, and vomiting; problems in the liver or pancreas; and development of other cancers. You should avoid the consumption of grapefruit and grapefruit juice during treatment with fedratinib. You may take the medication with or without food, but taking it with a high-fat meal may help reduce nausea and vomiting. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. 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.