Direct oral anticoagulants (DOACs) have emerged as safe and effective alternatives to Vitamin-K antagonists for treatment and prevention of arterial and venous thrombosis. Due to their novelty, pharmacokinetic DOAC drug-drug interactions (DDIs) that result in clinical adverse events have not been well-documented.
This study aims to systematically review reported pharmacokinetic DDIs resulting in clinical adverse events through documented observational evidence to better inform clinicians in clinical practice.
A comprehensive literature review of EMBASE, MEDLINE, and Ovid HealthStar was conducted through March 10th, 2020. Two independent reviewers screened and extracted data from eligible articles according to pre-established inclusion and exclusion criteria. Articles reporting bleeding or thrombotic outcomes in non-controlled (observational) settings resulting from suggested pharmacokinetic DOAC DDIs were included.
A total of 5567 citations were reviewed, of which 24 were included following data extraction. The majority were case reports ( n = 21) documenting a single adverse event resulting from a suspected DOAC DDI, while the remaining papers were a case series ( n = 1) and cohort studies ( n = 2). The most commonly reported interacting drugs were amiodarone and ritonavir (bleeding), and phenobarbital, phenytoin, and carbamazepine (thrombosis). Bleeding events more often resulted from a combined mechanism (P-glycoprotein AND CYP3A4 inhibition), whereas thrombotic events resulted from either combined OR single P-glycoprotein/CYP3A4 induction.
Patients on direct oral anticoagulants (DOACs) can encounter drug interactions.
Drug interactions can alter the amount of DOAC in a patient's system.
Research on DOAC interactions is currently limited and larger studies are required.
Health providers should continue to be cautious with potential DOAC interactions.