Identification and management of contraindicated drug-drug interactions through pharmaceutical care programs: Experience in direct-acting antivirals therapy.

BACKGROUND/PURPOSE: To investigate the impact of pharmaceutical care programs for the management of contraindicated drug-drug interactions (DDIs) in direct-acting antivirals (DAAs) therapy. METHODS: A prospective observational study was performed at Dalin Tzu Chi Hospital between January 2018 and December 2019. Pharmacists screened DDIs for all hepatitis C patients before DAA therapy. The study outcome included the frequency of contraindicated DDIs, acceptance rate, and cost avoidance of the pharmaceutical care program. RESULTS: A total of 1053 patients were enrolled in the study, with a mean age of 67.1 ± 11.9 years. Most patients received therapy with sofosbuvir/ledipasvir (37.1%; n = 391), elbasvir/grazoprevir (23.8%; n = 251), or glecaprevir/pibrentasvir (21.1%; n = 222). A total of 796 (75.6%) patients received at least one co-medication, with the average number of co-medications being 5.2 per patient (SD: 4.4/patient). In total, 1356 DDIs were identified, with the average DDIs per patient of 1.3 (SD: 1.7). For patients with contraindicated DDIs (2%, n = 102), statins and amiodarone were the most common co-medications. Physicians often accepted pharmacists' recommendations (acceptance rate of 72.5%) or withheld co-medication to avoid severe adverse drug events (ADEs). The estimated cost avoidance of preventable ADEs was USD 14,033 for contraindicated DDIs with pharmaceutical care programs. CONCLUSION: The implementation of pharmaceutical care programs in DAA therapy provides a favorable outcome and substantial cost avoidance.

Risk of rheumatoid arthritis in patients with hepatitis C virus infection receiving interferon-based therapy: a retrospective cohort study using the Taiwanese national claims database.

OBJECTIVES: To illuminate the association between interferon-based therapy (IBT) and the risk of rheumatoid arthritis (RA) in patients infected with hepatitis C virus (HCV). DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: This retrospective cohort study used Taiwan's Longitudinal Health Insurance Database 2005 that included 18 971 patients with HCV infection between 1 January 1997 and 31 December 2012. We identified 1966 patients with HCV infection who received IBT (treated cohort) and used 1:4 propensity score-matching to select 7864 counterpart controls who did not receive IBT (untreated cohort). OUTCOME MEASURES: All study participants were followed until the end of 2012 to calculate the incidence rate and risk of incident RA. RESULTS: During the study period, 305 RA events (3.1%) occurred. The incidence rate of RA was significantly lower in the treated cohort than the untreated cohort (4.0 compared with 5.5 per 1000 person-years, p<0.018), and the adjusted HR remained significant at 0.63 (95% CI 0.43 to 0.94, p=0.023) in a Cox proportional hazards regression model. Multivariate stratified analyses revealed that the attenuation in RA risk was greater in men (0.35; 0.15 to 0.81, p=0.014) and men<60 years (0.29; 0.09 to 0.93, p=0.036). CONCLUSIONS: This study demonstrates that IBT may reduce the risk of RA and contributes to growing evidence that HCV infection may lead to development of RA.