Real-life data on potential drug-drug interactions in patients with chronic hepatitis C viral infection undergoing antiviral therapy with interferon-free DAAs in the PITER Cohort Study

Background There are few real-life data on the potential drug-drug interactions (DDIs) between anti-HCV direct-acting antivirals (DAAs) and the comedications used. Aim To assess the potential DDIs of DAAs in HCV-infected outpatients, according to the severity of liver disease and comedication used in a prospective multicentric study. Methods Data from patients in 15 clinical centers who had started a DAA regimen and were receiving comedications during March 2015 to March 2016 were prospectively evaluated. The DDIs for each regimen and comedication were assigned according to HepC Drug Interactions (www.hep-druginteractions.org). Results Of the 449 patients evaluated, 86 had mild liver disease and 363 had moderate-to-severe disease. The use of a single comedication was more frequent among patients with mild liver disease (p = 0.03), whereas utilization of more than three drugs among those with moderate-to-severe disease (p = 0.05). Of the 142 comedications used in 86 patients with mild disease, 27 (20%) may require dose adjustment/closer monitoring, none was contraindicated. Of the 322 comedications used in 363 patients with moderate-to-severe liver disease, 82 (25%) were classified with potential DDIs that required only monitoring and dose adjustments; 10 (3%) were contraindicated in severe liver disease. In patients with mild liver disease 30% (26/86) used at least one drug with a potential DDI whereas of the 363 patients with moderate-to-severe liver disease, 161 (44%) were at risk for one or more DDI. Conclusions Based on these results, we can estimate that 30-44% of patients undergoing DAA and taking comedications are at risk of a clinically significant DDI. This data indicates the need for increased awareness of potential DDI during DAA therapy, especially in patients with moderate-to-severe liver disease. For several drugs, the recommendation related to the DDI changes from "dose adjustment/closer monitoring" in mild to moderate liver disease, to "the use is contraindicated" in severe liver disease

Virological failure at one year in triple-class experienced patients switching to raltegravir-based regimens is not predicted by baseline factors

We evaluated rates and determinants of virological failure in triple-class experienced patients receiving raltegravir-based regimens from a national observational study over 48 weeks, defined by any one of the following: (1) no HIV-RNA suppression to undetectable levels (<50 copies/mL) during follow-up; (2) detectable viral load after obtaining undetectable levels; and (3) leaving the study before 48 weeks. Among 101 eligible patients, 26 (25.7%; 95% CI 17.2-34.2) had virological failure. No significant differences between patients with and without virological failure were observed for gender, age, route of transmission, baseline CD4/HIV-RNA, CDC group, hepatitis B or C co-infections, resistance (based on the last genotype available), type and number of concomitant drug classes, concomitant use of darunavir, atazanavir, etravirine, enfuvirtide or maraviroc, and health-related quality-of-life measures. A high rate of treatment response was observed. The analyses did not identify any baseline factor associated with failure, including resistance status. Even if we cannot exclude the presence of pre-existing minority resistant variants not captured by genotypic tests, the lack of baseline predictors of failure suggests the need to monitor patients closely during follow up for other factors, such as potential drug interactions and reduced levels of adherence, which may favour virological failure

Correction: Real-life data on potential drug-drug interactions in patients with chronic hepatitis C viral infection undergoing antiviral therapy with interferon-free DAAs in the PITER cohort study (PLoS ONE (2017) 12: 2 (e0172159) DOI: 10.1371/journal.pone.0172159)

The graph that appears as Fig 2A is incorrectly duplicated in Fig 2B. Please see the corrected Fig 2 here.(Figure Presented)