Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with vadadustat may increase the plasma concentrations of drugs that are substrates of the CYP450 3A4 and/or CYP450 2C8 isoenzymes. Vadadustat is an inhibitor of CYP450 3A4 and CYP450 2C8 in vitro. However, clinical data are not available.

MANAGEMENT: Some authorities recommend using caution when vadadustat is used concomitantly with drugs that are substrates of CYP450 3A4 and/or CYP450 2C8, particularly sensitive substrates or those with a narrow therapeutic range. Monitoring for signs and symptoms of increased exposure to the CYP450 3A4 and/or CYP450 2C8 substrate should be considered whenever vadadustat is added to or withdrawn from therapy. The prescribing information for concomitant medications may be consulted to assess the benefits versus risks of coadministration, as well as any dosage adjustments that may be required during coadministration and/or following the discontinuation of a CYP450 3A4 and/or CYP450 2C8 inhibitor.

Alcohol can lower your blood pressure and add to the effects of dilTIAZem. You may experience dizziness, lightheadedness, fainting, or a rapid heartbeat if you drink alcohol with dilTIAZem, especially when you first start taking the medication or just after a dose increase. Grapefruit juice may also increase the effects of dilTIAZem in some people by increasing its levels in the blood. You may want to limit alcohol intake and avoid excessive consumption of grapefruit and grapefruit juice during treatment with dilTIAZem. However, if you have been regularly consuming grapefruit or grapefruit juice with dilTIAZem, do not alter the amounts of these products in your diet without first talking to your doctor or other healthcare professional. Contact your doctor if your condition changes or you experience increased side effects of dilTIAZem such as headache, irregular heartbeat, swelling, unexplained weight gain, or chest pain. Orange juice is not expected to interact.

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.

Using dilTIAZem together with multivitamin with minerals can decrease the effects of dilTIAZem. Talk with your doctor before using dilTIAZem and multivitamin with minerals together. You may need a dose adjustment or need your blood pressure checked more often if you take both medications. 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.