title: Decreased INR after acenocoumarol, ombitasvir/paritaprevir/ritonavir and dasabuvir co-administration.
abstract: OBJECTIVE
  Limited data are available on co-administration of acenocoumarol with direct-acting antiviral agents for chronic hepatitis C virus infection.
  
  
  METHODS
  We report a case of a patient who required a significant increase in acenocoumarol weekly dose probably due to an interaction with ombitasvir/paritaprevir/ritonavir and/or dasabuvir. A causality assessment of the drug-drug interaction leading to a reduced INR was conducted according to the Naranjo algorithm. A score of 6 suggested that the adverse drug reaction was probable.
  
  
  CONCLUSIONS
  Because of possible INR abnormalities during the concomitant use of acenocoumarol, ombitasvir/paritaprevir/ritonavir and dasabuvir, clinicians should closely monitor INR values.
authors.affiliation: Pharmacy Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: de Lorenzo-Pinto
authors.affiliation: Pharmacy Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
authors.forename: Á
authors.initials: Á
authors.lastname: Giménez-Manzorro
authors.affiliation: Pharmacy Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
authors.forename: C G
authors.initials: CG
authors.lastname: Rodríguez-González
authors.affiliation: Gastroenterology Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Ahumada-Jiménez
authors.affiliation: Pharmacy Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Herranz-Alonso
authors.affiliation: Pharmacy Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
authors.forename: M B
authors.initials: MB
authors.lastname: Marzal-Alfaro
authors.affiliation: Pharmacy Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Sanjurjo-Sáez
keywords: acenocoumarol; antiviral agents; drug interactions; hepatitis C