Drug Interactions between daclatasvir and Lanoxin

ADJUST DOSE: Coadministration with daclatasvir may increase the serum concentrations of digoxin. The proposed mechanism is daclatasvir inhibition of the P-glycoprotein-mediated renal tubular secretion of digoxin. When 0.125 mg once daily of digoxin was administered with 60 mg once daily daclatasvir, digoxin peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 65% and 27%, respectively.

MANAGEMENT: Serum digoxin levels and pharmacologic effects should be closely monitored following the addition or withdrawal of daclatasvir, and the digoxin dosage adjusted as needed. Patients already receiving daclatasvir who are initiating digoxin should start at the lowest appropriate digoxin dosage, with further adjustments based on serum digoxin levels and clinical response. Patients already receiving digoxin prior to initiating daclatasvir should have serum digoxin levels taken before starting daclatasvir, then have digoxin levels lowered by reducing dosage approximately 30% to 50% or by modifying the dosing frequency with continued monitoring. Patients should be advised to seek medical attention if they experience signs of digoxin toxicity such as nausea, anorexia, visual disturbances, slow pulse, or irregular heartbeat.