Drug Interactions between fedratinib and voclosporin

Food may delay and reduce the absorption of voclosporin, which may lead to lower blood levels of the medication and possibly reduced effectiveness. Voclosporin should be taken on an empty stomach at least 1 hour before or 2 hours after food. This will make it easier for your body to absorb the medication. Also, while taking voclosporin, you should avoid grapefruits and grapefruit juice. Grapefruit can raise the blood levels of voclosporin in your body and lead to increased adverse effects. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor. Also, if you are taking voclosporin you should avoid potassium-containing salt substitutes or over-the-counter potassium supplements without first talking to your doctor. Taking voclosporin together with these salt substitutes or supplements may cause high levels of potassium in your blood. High levels of potassium can cause weakness, irregular heartbeat, confusion, tingling of the extremities, or feelings of heaviness in the legs. Call your doctor at once if you have any of these symptoms. 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.

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.