Thank you for contacting Neurocrine Biosciences with your unsolicited Medical Information request regarding the dose of INGREZZA (valbenazine) capsules in patients taking P-gp substrate medications, such as digoxin.
INGREZZA is a vesicular monoamine transporter 2 (VMAT2) inhibitor indicated for the treatment of adults with tardive dyskinesia.
The INGREZZA Full Prescribing Information states the following:
Clinical Implication: Concomitant use of INGREZZA with digoxin increased digoxin levels because of inhibition of intestinal P-glycoprotein (P-gp).
Prevention or Management: Digoxin concentrations should be monitored when co-administering INGREZZA with digoxin. Increased digoxin exposure may increase the risk of exposure related adverse reactions. Dosage adjustment of digoxin may be necessary.
This letter and the enclosed material are provided in response to your unsolicited medical information inquiry. Please feel free to contact Neurocrine Medical Information at (877) 641-3461 or firstname.lastname@example.org if you would like to request additional information.
1. INGREZZA [package insert]. Neurocrine Biosciences, Inc., San Diego, CA; 2017
2. Important Safety Information. Neurocrine Biosciences, Inc., San Diego, CA; 2017