Drug-drug interactions in anti-HCV therapy: a comparison among options available in Italy.

After a long period of interferon-and ribavirin-based therapy (IFN/RBV), a very fast evolution in the development of directly acting antivirals (DAAs) has now established a totally new paradigm for the treatment chronic HCV infection. An efficacy rate within the 95-100% interval, safer and more tolerable drugs, much shorter treatment duration and a quicker establishment of the sustained virological response (SVR) are among the most relevant properties of new DAAs as compared to former IFN/RBV therapies. The last wave of DAAs is also characterized by a lesser tendency to generate or being victim of drug-drug interactions. Nevertheless, since the circumstances in which patients are also recipients of other medications are rather frequent, individualization of treatment is advised in order to minimize the risk of drug-drug interactions of clinical relevance. Three two-drug regimens are available in Italy for the treatment of chronic HCV infection: sofosbuvir/velpatasvir (SOF/VEL), glecaprevir/pibrentasvir (GLE/PIB) and grazoprevir/elbasvir (GZP/RLB). Based on the officially released summary of product characteristics (SmPC) of these three co-formulated dual regimens, we performed a comparative analysis concerning the drug-drug interactions possibly affecting the DAA regimens. According to specific individual conditions, including co-morbidities, the choice of the most appropriate regimen must carefully take into account, among the different variables, the metabolic profile of both DAAs and concurrent medications. The differences among the three regimens offer the possibility to avoid the occurrence of clinically relevant drug-drug interactions in most circumstance.