Drug Interactions between pralsetinib and sonidegib

Food should not be consumed for at least 2 hours before and at least 1 hour after taking pralsetinib. Do not consume grapefruit, grapefruit juice, any supplements that contain grapefruit, Seville oranges, or Seville orange juice as these products can increase the blood levels of pralsetinib. This may increase the risk and/or severity of serious side effects such as lung problems, liver problems, high blood pressure, fatigue, muscle and joint pain, and bleeding complications. Some sources also warn that combining these medicines could 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 disease, conduction abnormalities, or electrolyte disturbance (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. 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.

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.