Drug Interactions between lonafarnib and Rythmol SR

Lonafarnib should be taken with the morning and evening meals and an adequate amount of water. Do not consume grapefruit, grapefruit juice, or Seville oranges (also known as bitter or sour oranges).During treatment with lonafarnib. Juice from grapefruits and Seville oranges can increase the blood levels of lonafarnib. This may increase the risk and/or severity of side effects such as nausea, vomiting, diarrhea, loss of appetite, electrolyte (e.G., calcium, magnesium, potassium, phosphate, sodium) abnormalities, liver problems, low red and white blood cell counts, infection, and high blood pressure. 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.

Consumption of grapefruit, grapefruit juice, and supplements that contain grapefruit should be avoided during treatment with propafenone as they may increase the blood levels of propafenone in some patients. This can cause serious side effects such as new or worsening irregular heart rhythm or heart failure; chest pain; difficulty breathing; fluid retention and swelling; and slow heart rate and pulse. 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.