Apixaban

Effects of the antitumor drugs adagrasib and asciminib on apixaban metabolism in vitro and in vivo

Apixaban is an oral anticoagulant that directly inhibits the target Factor Xa (FXa). In this study, we focused on the in vivo and in vitro effects of adagrasib and asciminib on apixaban metabolism, to discover potential drug-drug interactions (DDI) and explore their inhibitory mechanisms. The levels of apixaban and its metabolite, O-desmethyl-apixaban (M2), were determined by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). In vitro evaluation, the maximum half inhibitory concentration (IC50) of adagrasib in rat liver microsomes (RLM) and human liver microsomes (HLM) against apixaban was 7.99 μM and 117.40 μM, respectively. The IC50 value of asciminib against apixaban in RLM and HLM was 4.28 μM and 18.42 μM, respectively. The results of the analysis on inhibition mechanisms showed that adagrasib inhibited the metabolism of apixaban through a non-competitive mechanism, while asciminib inhibited the metabolism of apixaban through a mixed mechanism. Moreover, the interaction of apixaban with adagrasib and asciminib in Sprague-Dawley (SD) rats was also investigated. It was found that the pharmacokinetic characteristics of apixaban were significantly changed when combined with these two antitumor drugs, where AUC(0-t), AUC(0-∞), t1/2, Tmax, and Cmax were increased, while CLz/F was significantly decreased. But both drugs did not appear to affect the metabolism of M2 in a significant way. Consistent results from in vitro and in vivo demonstrated that both adagrasib and asciminib inhibited the metabolism of apixaban. It provided reference data for the future clinical individualization of apixaban.

A comparison of apixaban and dabigatran etexilate for thromboprophylaxis following hip and knee replacement surgery

INTRODUCTION

Patients who have undergone hip or knee replacement surgery are exposed to a high risk of developing a post-operative venous thromboembolus and so have a need for an effective, medication-based, thrombosis prophylaxis. New orally active anticoagulants have been available for a few years now. These specific substances directly block either thrombin (e.g., dabigatran etexilate) or Factor Xa (e.g., apixaban). It is not clear whether there are any efficacy differences between these two substances because there have never been any head-to-head studies carried out.

MATERIALS AND METHODS

We have carried out a study comparing two new orally active anticoagulants dabigatran etexilate (Pradaxa^®) and apixaban (Eliquis^®) that were each given to two groups of 200 patients respectively, who had undergone elective hip or knee arthroplasty (100 each). Each patient was assessed for pre- and post-operative hemoglobin concentrations, post-operative blood loss, the number of transfused erythrocyte concentrates, the duration of wound secretion, clinical thromboembolic complications (deep vein thrombosis, pulmonary embolism, myocardial infarct), as well as gastrointestinal, intracranial or wound-related bleeding complications.

RESULTS

Dabigatran etexilate treatment led to a significant increase in the duration of wound secretion in both arthroplasty groups when compared to apixaban: wound secretion lasted 1.2 days longer on average in the dabigatran etexilate group than in the apixaban group (4.1 ± 2.1 vs. 2.9 ± 1.8 days). There were no significant differences observed between the two anticoagulant groups when comparing pre- and post-operative Hb values, post-operative blood loss and the other clinical parameters.

CONCLUSIONS

Thus, it appears that the direct thrombin inhibitor, dabigatran etexilate, is associated with a longer period of wound secretion following the implantation of hip and knee endoprostheses than that associated with the Factor Xa inhibitor, apixaban.