Drug Interactions between fenfluramine and sonidegib

Using fenfluramine with alcohol can increase the risk of cardiovascular side effects such as increased heart rate, chest pain, or blood pressure changes. In addition, you may also be more likely to experience nervous system side effects such as dizziness, drowsiness, depression, and difficulty concentrating. You should avoid or limit the use of alcohol while being treated with fenfluramine. Do not use more than the recommended dose of fenfluramine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication 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.