Direct-Acting Antivirals (Daklinza, Exviera, Harvoni, Olysio, Sovaldi, Victrelis, Viekirax, Zepatier and Epclusa)* are used to treat chronic hepatitis C virus (HCV) infection. These medicines reduce the amount of HCV in the body by preventing HCV from multiplying, and in most cases, they cure HCV.
A signal of a potential drug interaction leading to a reduced international normalised ratio (INR) has recently been identified with co-administration of Direct-Acting Antivirals and vitamin K antagonists. The case reports on which the signal was based were reviewed by the European Medicines Agency (EMA) Pharmacovigilance Risk Assessment Committee (PRAC). The PRAC has recommended that the product information of Direct-Acting Antivirals should be updated to include a recommendation for close monitoring of INR in patients treated with vitamin K antagonists, as liver function may change during treatment with Direct-Acting Antivirals. Pharmacokinetic studies with warfarin have been performed for Olysio, Viekirax and Exviera. While no change in the pharmacokinetics of warfarin is expected, close monitoring of INR is recommended with all vitamin K antagonists. This is due to liver function changes during treatment with Direct-Acting Antivirals.
Advice to Healthcare Professionals
As liver function may change during treatment with Direct-Acting Antivirals, it is recommended that INR is closely monitored in patients concurrently treated with vitamin K antagonists.
Key Message
- Liver function changes during treatment with Direct-Acting Antivirals may lead to a reduced INR in patients concurrently treated with warfarin and other vitamin K antagonists.
- Healthcare professionals should be alert to this potential interaction and closely monitor INR in these patients.
- The product information (Summary of Product Characteristics (SmPC) and Package Leaflet (PL)) for these products will be updated shortly.
*Daklinza (daclatasvir), Exviera (dasabuvir), Harvoni (sofosbuvir/ledipasvir), Olysio (simeprevir), Sovaldi (sofosbuvir), Victrelis (boceprevir) and Viekirax (ombitasvir/paritaprevir/ritonavir). Further details are available on www.hpra.ie and www.ema.europa.eu
The post Direct-Acting Antivirals for Hepatitis C: Advice on interaction potential with warfarin and other vitamin K antagonists leading to a reduced international normalised ratio (INR) appeared first on Irish Medical Times.