Drug Interactions between avapritinib and vadadustat

Avapritinib should be taken on an empty stomach, one hour before or two hours after a meal. Do not consume grapefruit, grapefruit juice, or any supplements that contain grapefruit extract during treatment with avapritinib unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of avapritinib. This may increase the risk and/or severity of serious side effects such as bleeding in the brain; cognitive impairment (forgetfulness, confusion, trouble thinking); changes in mood or behavior; hallucinations; fluid retention or swelling; and decreases in blood cell counts. You may also be more likely to develop anemia, bleeding problems, or infections due to low blood cell counts. 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.

Consumer information for this interaction is not currently available.

MONITOR: Smoking and alcohol consumption during therapy with vadadustat may increase the risk of gastrointestinal erosions. Serious erosions, including gastrointestinal bleeding and the need for red blood cell transfusions, have been reported during vadadustat clinical trials. Patients with a history of gastrointestinal erosion, peptic ulcer disease, and current tobacco smokers and alcohol drinkers may be at higher risk of gastrointestinal injury.

MANAGEMENT: Caution is advised if vadadustat is prescribed to current tobacco smokers or alcohol drinkers. Patients should be advised to contact their physician if they develop potential signs and symptoms of gastrointestinal injury such as abdominal pain, hematemesis, trouble swallowing, chest or throat pain, and/or black, tarry stools.