Prevalence and predictors of inappropriate apixaban dosing in patients with non-valvular atrial fibrillation at a large tertiary academic medical institution

Objectives The aim of this study was to assess apixaban prescribing practices for stroke prevention in patients with non-valvular atrial fibrillation (NVAF), and to examine the factors contributing to dosing inappropriateness at a large academic medical institution in Saudi Arabia. Methodology A retrospective cohort analysis of all adult patients with NVAF receiving apixaban for stroke prevention was conducted for the period from June 2015 to May 2019. Results Of the 1271 patients included in the analysis, inappropriate apixaban dosing was present in 223 (17.50%) patients and absent in 1048 (82.50%) patients. Among those who received an inappropriate apixaban dosage, 103 (46.19%) and 120 (53.81%) received an over- or under-dosed apixaban regimen, respectively. Increasing age, lower body mass index, a history of minor bleeding, concomitant antiplatelet therapy with either clopidogrel + aspirin or aspirin only, reduced renal function, and elevated CHA 2 DS 2 -VASc score were significantly associated with increasing the risk of receiving an inappropriate apixaban dosage. Conclusion In patients with NVAF receiving apixaban for stroke prevention in this real-world analysis, > 80% were prescribed an appropriate dosage of apixaban. Proactive procedures, such as integrating an electronic dosing algorithm, educating healthcare providers, and involving clinical pharmacists in medication review, may help ensure the use of appropriate apixaban dosages.