Assessment of Anti-Xa activity in patients receiving concomitant apixaban with strong p-glycoprotein inhibitors and statins

Peak and trough concentrations of apixaban and rivaroxaban in adult patients: a systematic review and meta-analysis

BACKGROUND

Apixaban and rivaroxaban are activated factor X (FXa) inhibitors commonly used for treatment of venous thromboembolism and stroke prevention in patients with atrial fibrillation. While routine monitoring of their concentrations is not recommended, but it may be beneficial in certain situations. Expected peak and trough concentrations remain poorly understood, with most data derived from small studies.

OBJECTIVES

To establish the average peak and trough concentrations of apixaban and rivaroxaban from real-world studies.

METHODS

PubMed, Scopus, and Web of Science were searched until October 2023 for observational studies reporting apixaban and rivaroxaban concentrations. Meta-regression was used to examine factors influencing these concentrations.

RESULTS

Sixteen studies involving 1054 apixaban and 1321 rivaroxaban patients were pooled using random-effects model. Mean apixaban peak concentrations were 157 ng/mL (95% CI, 127-187) for 2.5 mg and 228 ng/mL (95% CI, 204-252) for 5 mg, with trough concentrations of 77 ng/mL (95% CI, 56-98) and 113 ng/mL (95% CI, 101-124), respectively. Mean rivaroxaban peak concentrations were 168 ng/mL (95% CI, 104-232) for 10 mg, 225 ng/mL (95% CI, 192-257) for 15 mg, and 229 ng/mL (95% CI, 193-264) for 20 mg, with trough concentrations of 23 ng/mL (95% CI, 13-32), 31 ng/mL (95% CI, 26-36), and 36 ng/mL (95% CI, 25-47), respectively. Meta-regression revealed age and creatinine clearance correlated with apixaban peak concentrations. Creatinine clearance correlated with apixaban and rivaroxaban trough concentrations.

CONCLUSION

The pooled mean concentrations align with expected concentration ranges reported in different pharmacokinetic studies.

Lansoprazole (LPZ) reverses multidrug resistance (MDR) in cancer through impeding ATP-binding cassette (ABC) transporter-mediated chemotherapeutic drug efflux and lysosomal sequestration

AIMS

Lansoprazole is one of the many proton pump inhibitors (PPIs) that acts more strongly with ABCB1 and ABCG2. The present study is to investigate the potential of lansoprazole on reversal of ABCB1/G2-mediated MDR in cancer, in vitro and in vivo.

METHODS

Reversal studies and combination evaluation were conducted to determine the synergistic anti-MDR effects on lansoprazole. Lysosomal staining was used to determination of lansoprazole on ABCB1-mediated lysosomal sequestration. Substrate accumulation and efflux assays, ATPase activity, and molecular docking were conducted to evaluate lansoprazole on ABCB1/G2 functions. Western blot and immunofluorescence were used to detect lansoprazole on ABCB1/G2 expression and subcellular localization. MDR nude mice models were established to evaluate the effects of lansoprazole on MDR in vivo.

RESULTS

Lansoprazole attenuated ABCB1/G2-mediated MDR and exhibited synergistic effects with substrate drugs in MDR cells. In vivo experiments demonstrated that lansoprazole attenuated ABCB1/G2-mediated MDR and exhibited synergistic effects that augmented the sensitivity of substrate anticancer drugs in ABCB1/G2-mediated settings without obvious toxicity. Lansoprazole impeded lysosomal sequestration mediated by ABCB1, leading to a substantial increase in intracellular accumulation of substrate drugs. The effects of lansoprazole were not attributable to downregulation or alterations in subcellular localization of ABCB1/G2. Lansoprazole promoted the ATPase activity of ABCB1/G2 and competitively bound to the substrate-binding region of ABCB1/G2.

CONCLUSIONS

These findings present novel therapeutic avenues whereby the combination of lansoprazole and chemotherapeutic agents mitigates MDR mediated by ABCB1/G2 overexpression.

Does amiodarone impact on apixaban levels? The effect of amiodarone on apixaban level among Thai patients with non-valvular Atrial Fibrillation

BACKGROUND

Apixaban and amiodarone are drugs used for non-valvular atrial fibrillation (NVAF) in routine practice. The evidence about apixaban plasma levels in patients who receive apixaban with amiodarone, including bleeding outcomes, has been limited. This study aimed to compare the apixaban plasma levels and bleeding outcomes between apixaban monotherapy and apixaban with amiodarone groups.

METHODS

This study was a prospective, observational, and single-center research which was conducted from January 2021 to January 2022 in NVAF patients who received apixaban at a tertiary care hospital located in the center of Bangkok, Thailand.

RESULTS

Thirty-three patients were measured for their median (5th-95th percentile) apixaban plasma levels. The trough of apixaban plasma level (Ctrough) were 108.49 [78.10-171.52] and 162.05 [87.94-292.88] μg/L in the apixaban monotherapy and apixaban with amiodarone groups, respectively (p = 0.028). Additionally, the peaks of apixaban plasma level (Cpeak) were 175.36 [122.94-332.34] and 191 [116.88-488.21] μg/L in the apixaban monotherapy and apixaban with amiodarone groups, respectively (p = 0.375). There was bleeding that occurred in 7 patients (21.21%); 5 patients in the apixaban monotherapy group and 2 patients in the apixaban with amiodarone group, respectively.

CONCLUSIONS

Amiodarone may increase the peaks and troughs of apixaban plasma levels. The co-administration of apixaban with amiodarone is generally well tolerated. However, the careful observation of bleeding symptoms in individual cases is necessary to ensure safety.

DOAC plasma concentration upon hospital admission in a cohort of trauma patients. An observational real-life study

PURPOSE

Due to a better safety profile, direct oral anticoagulants (DOACs) are increasingly prescribed for prevention of thromboembolic events. However, little is known about DOAC plasma concentrations in trauma patients upon hospital admission. Thus, we investigated the frequency and extent of DOAC possible over- and underdosing in trauma patients upon hospital admission.

METHODS

In this single-center retrospective study, DOAC plasma concentrations of adult trauma patients were analyzed with specific calibrated anti-IIa (dabigatran) and anti-Xa (apixaban, edoxaban and rivaroxaban) tests within 4 h after hospital admission.

RESULTS

A total of 210 trauma patients, admitted between 2019 and 2022, were included in the analyses. Low DOAC levels < 30 ng/mL were detected in 13.3% of the patients. In 7.1% of the patients, DOAC plasma levels ranged between 300-399 ng/mL and further 7.1% exhibited plasma concentrations > 400 ng/mL. The highest incidence of high to very high DOAC plasma concentration was observed for patients on rivaroxaban and dabigatran. A moderate correlation was observed between dabigatran plasma concentration and estimated glomerular filtration rate (rho = - 0.5338, p = 0.0003). For rivaroxaban no clear association between plasma concentration and liver or renal function could be detected. Patients on statins had significantly higher DOAC concentration in comparison with those not taking statins (153 (76-274) vs 108 (51-217) ng/mL, p = 0.046).

CONCLUSION

The current study revealed that patients on dabigatran and rivaroxaban were prone to higher DOAC plasma levels upon hospital admission in comparison with apixaban and edoxaban. DOAC plasma level measurement in trauma patients might be warranted due to unpredictively low or high plasma concentrations. However, the clinical impact of altered plasma levels on both, bleeding and thromboembolic events, remains to be determined by future studies.

Advances in the structure, mechanism and targeting of chemoresistance-linked ABC transporters

Cancer cells frequently display intrinsic or acquired resistance to chemically diverse anticancer drugs, limiting therapeutic success. Among the main mechanisms of this multidrug resistance is the overexpression of ATP-binding cassette (ABC) transporters that mediate drug efflux, and, specifically, ABCB1, ABCG2 and ABCC1 are known to cause cancer chemoresistance. High-resolution structures, biophysical and in silico studies have led to tremendous progress in understanding the mechanism of drug transport by these ABC transporters, and several promising therapies, including irradiation-based immune and thermal therapies, and nanomedicine have been used to overcome ABC transporter-mediated cancer chemoresistance. In this Review, we highlight the progress achieved in the past 5 years on the three transporters, ABCB1, ABCG2 and ABCC1, that are known to be of clinical importance. We address the molecular basis of their broad substrate specificity gleaned from structural information and discuss novel approaches to block the function of ABC transporters. Furthermore, genetic modification of ABC transporters by CRISPR-Cas9 and approaches to re-engineer amino acid sequences to change the direction of transport from efflux to import are briefly discussed. We suggest that current information regarding the structure, mechanism and regulation of ABC transporters should be used in clinical trials to improve the efficiency of chemotherapeutics for patients with cancer.

Risk for Bleeding-Related Hospitalizations During Use of Amiodarone With Apixaban or Rivaroxaban in Patients With Atrial Fibrillation : A Retrospective Cohort Study

BACKGROUND

Amiodarone, the most effective antiarrhythmic drug in atrial fibrillation, inhibits apixaban and rivaroxaban elimination, thus possibly increasing anticoagulant-related risk for bleeding.

OBJECTIVE

For patients receiving apixaban or rivaroxaban, to compare risk for bleeding-related hospitalizations during treatment with amiodarone versus flecainide or sotalol, antiarrhythmic drugs that do not inhibit these anticoagulants' elimination.

DESIGN

Retrospective cohort study.

SETTING

U.S. Medicare beneficiaries aged 65 years or older.

PATIENTS

Patients with atrial fibrillation began anticoagulant use between 1 January 2012 and 30 November 2018 and subsequently initiated treatment with study antiarrhythmic drugs.

MEASUREMENTS

Time to event for bleeding-related hospitalizations (primary outcome) and ischemic stroke, systemic embolism, and death with or without recent (past 30 days) evidence of bleeding (secondary outcomes), adjusted with propensity score overlap weighting.

RESULTS

There were 91 590 patients (mean age, 76.3 years; 52.5% female) initiating use of study anticoagulants and antiarrhythmic drugs, 54 977 with amiodarone and 36 613 with flecainide or sotalol. Risk for bleeding-related hospitalizations increased with amiodarone use (rate difference [RD], 17.5 events [95% CI, 12.0 to 23.0 events] per 1000 person-years; hazard ratio [HR], 1.44 [CI, 1.27 to 1.63]). Incidence of ischemic stroke or systemic embolism did not increase (RD, -2.1 events [CI, -4.7 to 0.4 events] per 1000 person-years; HR, 0.80 [CI, 0.62 to 1.03]). The risk for death with recent evidence of bleeding (RD, 9.1 events [CI, 5.8 to 12.3 events] per 1000 person-years; HR, 1.66 [CI, 1.35 to 2.03]) was greater than that for other deaths (RD, 5.6 events [CI, 0.5 to 10.6 events] per 1000 person-years; HR, 1.15 [CI, 1.00 to 1.31]) (HR comparison: P = 0.003). The increased incidence of bleeding-related hospitalizations for rivaroxaban (RD, 28.0 events [CI, 18.4 to 37.6 events] per 1000 person-years) was greater than that for apixaban (RD, 9.1 events [CI, 2.8 to 15.3 events] per 1000 person-years) (P = 0.001).

LIMITATION

Possible residual confounding.

CONCLUSION

In this retrospective cohort study, patients aged 65 years or older with atrial fibrillation treated with amiodarone during apixaban or rivaroxaban use had greater risk for bleeding-related hospitalizations than those treated with flecainide or sotalol.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute.

Do Apixaban Plasma Levels Relate to Bleeding? The Clinical Outcomes and Predictive Factors for Bleeding in Patients with Non-Valvular Atrial Fibrillation

Apixaban can significantly prevent stroke events in patients with non-valvular atrial fibrillation (NVAF), as can be observed from the large, randomized, controlled trial conducted in the present study. However, the real-world evidence of bleeding events related to the apixaban plasma levels in Asian populations is limited. This study aimed to investigate the apixaban plasma levels and clinical outcomes among NVAF patients receiving apixaban, including determining the risk factors associated with bleeding during routine care. Seventy-one patients were included in the study. The median values were 112.79 (5–95th percentiles: 68.69–207.8) μg/L and 185.62 (5–95th percentiles: 124.06–384.34) μg/L for the apixaban trough (C_trough) and apixaban peak plasma levels (C_peak), respectively. Stroke and bleeding were found in 8 (11.27%) and 14 patients (19.72%), respectively. There was no statistical significance for C_trough and C_peak in the stroke and non-stroke groups, respectively. The median of C_trough (139.15 μg/L) in patients with bleeding was higher than that in the non-bleeding group (108.14 μg/L), but there was no statistical significance. However, multivariate analyses showed that bleeding history (odds ratio (OR): 17.62; 95% confidence interval (CI): 3.54–176.64; and p-value = 0.002) and C_trough (OR: 1.01; 95%: CI 1.00–1.03; and p-value = 0.038) were related to bleeding events. Almost all of the patients presented apixaban plasma levels within the expected range. Interestingly, bleeding events were associated with the troughs of the apixaban plasma levels and bleeding history.