@article {Margusino-Frami{\~n}{\'a}n16, author = {Luis Margusino-Frami{\~n}{\'a}n and Purificaci{\'o}n Cid-Silva and Victor Gim{\'e}nez-Arufe and Cristina Mondelo-Garc{\'\i}a and Carla Fern{\'a}ndez-Oliveira and {\'A}lvaro Mena-de-Cea and Isabel Mart{\'\i}n-Herranz and {\'A}ngeles Castro-Iglesias}, title = {Influence of drug{\textendash}drug interactions on effectiveness and safety of direct-acting antivirals against hepatitis C virus}, volume = {28}, number = {1}, pages = {16--21}, year = {2021}, doi = {10.1136/ejhpharm-2019-001889}, publisher = {BMJ Specialist Journals}, abstract = {Objectives Direct-acting antivirals are the recommended treatment for hepatitis C-infected patients. Drug{\textendash}drug interactions with concomitant treatments can cause lack of effectiveness and/or safety. The objective of this study is to characterise drug{\textendash}drug interactions of direct-acting antivirals and to analyse their influence both on the effectiveness of antiviral treatment and on the overall safety of pharmacological treatment in hepatitis C-infected patients.Methods Observational and prospective cohort study for 3 years in the pharmaceutical care outpatient consultation of a general hospital, undertaking detection, evaluation and management of drug{\textendash}drug interactions by clinical pharmacists and physicians. The main outcome measures were sustained virologic response at week 12 for effectiveness and serious drug-related adverse events for safety. Multivariate statistical analysis applied to: (a) patient basal characteristics related to presence of drug{\textendash}drug interactions; (b) previous antiviral treatments, viral genotype, cirrhosis, decompensations and presence of drug{\textendash}drug interactions related to the effectiveness of direct-acting antivirals.Results Of a total of 1092 patients, the majority of them were men, around 60 years old and HCV-genotype 1 mono-infected, with a high basal viral load, naive to antiviral treatment, treated with ledipasvir/sofosbuvir and without cirrhosis. 24.5\% had drug{\textendash}drug interactions. Proton pump inhibitors were the concomitant drugs that caused the most drug{\textendash}drug interactions. Age >=65 years and direct-acting antivirals based on protease inhibitors were independently related to the presence of drug-drug interactions (p<=0.012). All (100\%) of the therapeutic recommendations based on detected drug{\textendash}drug interactions were implemented; 97.7\% of patients with interactions versus 99.0\% without them reached sustained virologic failure (p=0.109). The serious adverse events rates were 1.5\% and 1.3\% in patients with and without drug-drug interactions, respectively (p=0.841).Conclusions Drug{\textendash}drug interactions are frequent among hepatitis C-infected patients receiving treatment with direct-acting antivirals. However, the collaboration between physicians and clinical pharmacists makes it possible to detect, evaluate, avoid or clinically manage these drug{\textendash}drug interactions, in order to maintain whole treatment therapeutic safety and the effectiveness of direct-acting antivirals.}, issn = {2047-9956}, URL = {https://ejhp.bmj.com/content/28/1/16}, eprint = {https://ejhp.bmj.com/content/28/1/16.full.pdf}, journal = {European Journal of Hospital Pharmacy} }