[Biliary and kidney lithiasis during treatment with daclatasvir/sofosbuvir/ribavirin and atazanavir/ritonavir + abacavir/lamivudine in an HIV/HCV genotype 4-infected patient: a case report.]

New Direct-acting Antiviral Agents (DAA)-based anti-HCV therapies currently provide extraordinary opportunities to cure patients. Drug-drug interactions are however a real challenge during treatment. In particular, in HIV-infected patients in cART, DAA choice is limited by such interactions, which can result both in reduced efficacy and toxicity. We report the case of a HIV-infected patient on cART with atazanavir/ritonavir/abacavir/lamivudine, who presented kidney and biliary lithiasis, the latter treated with endoscopic retrograde cholangiopancreatography and endoscopic biliary sphincterotomy, after beginning anti-HCV treatment with daclatasvir/sofosbuvir/ribavirin. Hyperbilirubinemia with or without jaundice is a well known side effect of atazanavir, because of its inhibition of uridine diphosphate-glucuronosyl transferase. We speculate that in this case hyperbilirubinemia worsening was due to atazanavir/ribavirin co-administration. However, pharmacokinetic data are lacking about atazanavir/daclatasvir concomitant administration in real life setting.