Ombitasvir/Paritaprevir/Ritonavir + Digoxin = Precautionary

Study Design

Eight one sequence crossover, drug-drug interaction studies were conducted to assess the impact on PK values for the 2D regimen, Ombitasvir (25mg daily) + Paritaprevir/Ritonavir (150/100mg).These studies were conducted in healthy volunteers aged 18 to 55 years of age. A total of 12 participants were included in the evaluation of Ketoconazole vs. 2D Regimen.The 2D regimen was administered alone on Day 1. This was followed by a washout period on Days 2 through 7. On Days 8 and 9, Ketoconazole (400mg QD) was administed alone. On Day 10, the 2D regimen was administered with Ketoconazole. On Days 11 through 13, Ketoconazole was administered alone.

Study Results

DrugCmax GMR (90% CI)AUC GMR (90% CI)Ombitasvir0.99 (0.95-1.04)1.02 (0.98-1.06)Paritaprevir1.15 (0.97-1.36)1.12 (1.00-1.25)Ritonavir1.06 (0.99-1.13)1.01 (0.98-1.05)Digoxin1.58 (1.43-1.73)1.36 (1.21-1.53)Co-administration of digoxin and the 2D regimen resulted in increased PK parameters of digoxin. The authors recommend reducing the digoxin dose by 30-50% when these agents are co-administered. Routine therapeutic drug monitoring is also recommended due to the low therapeutic index of digoxin and the wide confidence intervals reported.

Study Conclusions

References

P Badri, S Dutta, H Wang, et al. Drug interactions with direct acting antiviral combination of paritaprevir/ritonavir ombitasvir. 16th International Workshop On Clinical Pharmacology Of Hiv ; Hepatitis Therapy. Washington, DC. ; 2015.