Investigating the Relationship Between Anti-seizure Medications and Bleeding Disorders: A Comprehensive Review of the Current Literature

Anti-seizure medications (ASMs) are specific types of anticonvulsants used to treat epileptic seizures. However, several studies have shown an association between ASMs and an increased risk of hematological disorders, such as thrombocytopenia, aplastic anemia, and platelet function disorders leading to prolonged bleeding times. This review explores the existing literature on this topic, investigating a wide variety of ASMs, ranging from first-generation medications to newer ones. A comprehensive search was conducted on all the currently approved ASMs using PubMed and Google Scholar: review articles, clinical trials, meta-analysis, observational studies, case reports, and relevant animal studies were identified. We extracted 15 ASMs including valproic acid (VPA), carbamazepine, phenytoin, phenobarbital, diazepam, clonazepam, lamotrigine, levetiracetam, oxcarbazepine, felbamate, topiramate, pregabalin, lacosamide, cannabidiol (CBD), and perampanel that contain considerable literature regarding different coagulopathies. An in-depth review of over 140 studies revealed a robust association between ASM-induced changes and the onset of bleeding disorders via several different mechanisms. Polytherapy, the use of multiple ASMs, also emerged as a significant risk factor for the development of coagulopathies. This review highlights the potential link between ASMs and bleeding disorders, emphasizing the importance of considering this risk during treatment planning. By understanding these associations, healthcare providers can optimize patient outcomes and minimize bleeding risks. Additionally, this review identifies the need for further research to bridge current knowledge gaps in clinical pharmacology related to ASMs and bleeding disorders.

Fear of the Dark: Concomitant Use of Direct Oral Anticoagulants and Antiseizure Medications

Direct-Acting Oral Anticoagulants and Antiseizure Medications for Atrial Fibrillation and Epilepsy and Risk of Thromboembolic Events Acton EK, Hennessy S, Gelfand MA, Leonard CE, Bilker WB, Shu D, Willis AW, Kasner SE. JAMA Neurol. 2024 Jul 8:e242057. doi: 10.1001/jamaneurol.2024.2057. Epub ahead of print. PMID: 38976246; PMCID: PMC11231911. Importance: Direct-acting oral anticoagulants (DOACs) are commonly prescribed with antiseizure medications (ASMs) due to the concurrency of and the association between atrial fibrillation (AF) and epilepsy. However, enzyme-inducing (EI) ASMs may reduce absorption and accelerate the metabolism of DOACs, potentially lowering DOAC levels and elevating thromboembolism risk. Objective: To assess the rates of thromboembolic and major bleeding events in adults with AF and epilepsy dispensed DOACs and EI ASMs versus DOACs with non-EI ASMs. Design, setting, and participantsDesign, setting, and participants. This active-comparator, new-user cohort study included US healthcare data from the Clinformatics Data Mart database from October 2010 to September 2021 for a nationally representative population of adults with AF and epilepsy. Exposure: Evaluations included episodes of contiguous coadministration of DOACs for AF with EI ASMs (exposed) or non-EI ASMs (referent) for epilepsy. Main outcomes and measures: Thromboembolic events (primary outcome) and major bleeding events (secondary outcome) were identified based on a series of validated, diagnosis-based coding algorithms. Data-adaptive, high-dimensional propensity score matching was used to control for observed confounders and proxies for unobserved confounders. Adjusted hazard ratios (AHRs) were estimated using Cox proportional hazards regression models with robust variance estimators to account for clustering within matched pairs. Results: This study included 14 078 episodes (median age, 74 [IQR, 67-81]; 52.4%female) and 14 158 episodes (median age, 74 [IQR, 67-81]; 52.4%female) of incident DOAC and ASM use that met eligibility criteria for assessment of thromboembolic and major bleeding outcomes, respectively. Incidence was 88.5 per 1000 person-years for thromboembolic events and 68.3 per 1000 person-years for bleeding events. Compared with the use of non-EI ASMs, the use of EI ASMs with DOACs was not associated with a difference in risk of thromboembolic events (AHR, 1.10; 95%CI, 0.82-1.46) but was associated with a reduction in risk of major bleeding events (AHR, 0.63; 95%CI, 0.44-0.89). Conclusions and relevance: In this cohort study, EI ASMs were not associated with alteration in DOAC efficacy. Further research is needed on the reduction in bleeding risk associated with EI ASMs, as this may suggest that pharmacokinetic interactions are associated with lowering DOAC levels without negating therapeutic effects.

[Pathogenesis and potential diagnostic biomarkers of atrial fibrillation in Chinese population: a study based on bioinfor-matics]

OBJECTIVES

To explore the pathogenesis and potential biomarkers of atrial fibrillation based on bioinformatics.

METHODS

Differentially expressed genes and module genes related to atrial fibrillation were obtained from GSE41177 and GSE79768 datasets (Chinese-origin tissue samples) through differential expression analysis and weighted gene co-expression network analysis. Candidate hub genes were obtained by taking intersections, and hub genes were obtained after gender stratification. Subsequently, functional enrichment analysis and immune infiltration analysis were performed. Four machine learning models were constructed based on the hub genes, and the optimal model was selected to construct a prediction nomogram. The prediction ability of the nomogram was verified using calibration curves and decision curves. Finally, potential therapeutic drugs for atrial fibrillation were screened from the DGIdb database.

RESULTS

A total of 67 differentially expressed genes and 65 module genes related to atrial fibrillation were identified. Functional enrichment analysis indicated that the pathogenesis of atrial fibrillation was closely related to inflammatory response, immune response, and immune and infectious diseases. Four common hub genes (TYROBP, FCER1G, EVI2B and SOD2), and two genes specifically expressed in male (PILRA and SLC35G3) and female (HLA-DRA and GATP) patients with atrial fibrillation were obtained after gender-segregated screening. The extreme gradient boosting model had satisfactory diagnostic efficiency, and the nomogram constructed based on the hub genes, male significant variables (PILRA, SLC35G3 and SOD2), and female significant variables (FCER1G, SOD2 and TYROBP) had satisfactory predictive ability. Immune infiltration analysis demonstrated a disturbed immune infiltration microenvironment in atrial fibrillation with a higher abundance of plasma cells, neutrophils, and γδT cells, with a higher abundance of neutrophils in males and resting mast cells in females. Two potential drugs for the treatment of atrial fibrillation, valproic acid and methotrexate, were obtained by database and literature screening.

CONCLUSIONS

The pathogenesis of atrial fibrillation is closely related to inflammation and immune response, and the microenvironment of immune cell infiltration of cardiomyocytes in the atrial tissue of patients with atrial fibrillation is disordered. TYROBP, FCER1G, EVI2B and SOD2 serve as potential diagnostic biomarkers of atrial fibrillation; PILRA and SLC35G3 serve as potential specific diagnostic biomarkers of atrial fibrillation in the male population, which can effectively predict the risk of atrial fibrillation development and are also potential targets for the treatment of atrial fibrillation.

Direct-Acting Oral Anticoagulants and Antiseizure Medications for Atrial Fibrillation and Epilepsy and Risk of Thromboembolic Events

Importance

Direct-acting oral anticoagulants (DOACs) are commonly prescribed with antiseizure medications (ASMs) due to concurrency of and the association between atrial fibrillation (AF) and epilepsy. However, enzyme-inducing (EI) ASMs may reduce absorption and accelerate metabolism of DOACs, potentially lowering DOAC levels and elevating thromboembolism risk.

Objective

To assess the rates of thromboembolic and major bleeding events in adults with AF and epilepsy dispensed DOACs and EI ASMs vs DOACs with non-EI ASMs.

Design, Setting, and Participants

This active-comparator, new-user cohort study included US health care data from the Clinformatics Data Mart database from October 2010 to September 2021 for a nationally representative population of adults with AF and epilepsy.

Exposure

Evaluations included episodes of contiguous coadministration of DOACs for AF with EI ASMs (exposed) or non-EI ASMs (referent) for epilepsy.

Main Outcomes and Measures

Thromboembolic events (primary outcome) and major bleeding events (secondary outcome) were identified based on a series of validated, diagnosis-based coding algorithms. Data-adaptive, high-dimensional propensity score matching was used to control for observed confounders and proxies for unobserved confounders. Adjusted hazard ratios (AHRs) were estimated using Cox proportional hazards regression models with robust variance estimators to account for clustering within matched pairs.

Results

This study included 14 078 episodes (median age, 74 [IQR, 67-81]; 52.4% female) and 14 158 episodes (median age, 74 [IQR, 67-81]; 52.4% female) of incident DOAC and ASM use that met eligibility criteria for assessment of thromboembolic and major bleeding outcomes, respectively. Incidence was 88.5 per 1000 person-years for thromboembolic events and 68.3 per 1000 person-years for bleeding events. Compared with use of non-EI ASMs, use of EI ASMs with DOACs was not associated with a difference in risk of thromboembolic events (AHR, 1.10; 95% CI, 0.82-1.46) but was associated with a reduction in risk of major bleeding events (AHR, 0.63; 95% CI, 0.44-0.89).

Conclusions and Relevance

In this cohort study, EI ASMs were not associated with alteration in DOAC efficacy. Further research is needed on the reduction in bleeding risk associated with EI ASMs, as this may suggest that pharmacokinetic interactions are associated with lowering DOAC levels without negating therapeutic effects.

Direct Oral Anticoagulants and Concomitant Anti-seizure Medications: A Retrospective, Case-Control Study in a Real-World Setting

PURPOSE

Although prescription of direct oral anticoagulants (DOACs) for epileptic patients on anti-seizure medications (ASMs) is on the increase, international guidelines pose strict restrictions because this may lead to pharmacologic interactions. However, current evidence on their clinical relevance remains scanty. This retrospective, case-control study assessed the frequency of ischemic/hemorrhagic events and epileptic seizures involving DOAC-ASM cotherapy in the real world, compared with DOAC and ASM monotherapy, in age- and gender-matched controls.

METHODS

Data on patients who had been prescribed a concomitant DOAC and ASM therapy for at least 6 months were extracted from the database of the Pharmaceutical Service of the Alessandria Province (Italy). After exclusions, the case group included 124 patients, 44 on valproic acid (VPA) and 80 on levetiracetam (LEV) concomitant with a DOAC, and it was compared with the DOAC-control and ASM-control groups. The clinical and laboratory data were extracted from the electronic archives of the hospitals in the same province.

FINDINGS

Two (1.6%) ischemic and 2 (1.6%) major hemorrhagic events were observed in the case group. Four (3.2%) ischemic and no hemorrhagic events occurred in the DOAC-control group. There were no statistically significant differences in the ischemic and hemorrhagic events between the case group (patients on concomitant LEV or VPA who were prescribed a DOAC) and the DOAC-control group, and there was no difference in the recurrence rate of epileptic seizures between the case group and the ASM-control group.

IMPLICATIONS

Although this study has some limits, mainly the small sample size, our findings indicate that neither LEV nor VPA concomitant treatment significantly affects the effects of DOACs in a real-world setting.

Practical guidance for direct oral anticoagulant use in the treatment of venous thromboembolism in primary and metastatic brain tumor patients

Management of venous thromboembolism (VTE) in patients with primary and metastatic brain tumors (BT) is challenging because of the risk of intracranial hemorrhage (ICH). There are no prospective clinical trials evaluating safety and efficacy of direct oral anticoagulants (DOACs), specifically in patients with BT, but they are widely used for VTE in this population. A group of neuro-oncology experts convened to provide practical clinical guidance for the off-label use of DOACs in treating VTE in patients with BT. We searched PubMed for the following terms: BTs, glioma, glioblastoma (GBM), brain metastasis, VTE, heparin, low-molecular-weight heparin (LWMH), DOACs, and ICH. Although prospective clinical trials are needed, the recommendations presented aim to assist clinicians in making informed decisions regarding DOACs for VTE in patients with BT.

Interactions between antiepileptic drugs and direct oral anticoagulants for primary and secondary stroke prevention

INTRODUCTION

Direct oral anticoagulants (DOAC) are the guideline-recommended therapy for prevention of stroke in atrial fibrillation (AF) and venous thromboembolism. Since approximately 10% of patients using antiepileptic drugs (AED) also receive DOAC, aim of this review is to summarize data about drug-drug interactions (DDI) of DOAC with AED by using data from PubMed until December 2023.

AREAS COVERED

Of 49 AED, only 16 have been investigated regarding DDI with DOAC by case reports or observational studies. No increased risk for stroke was reported only for topiramate, zonisamide, pregabalin, and gabapentin, whereas for the remaining 12 AED conflicting results regarding the risk for stroke and bleeding were found. Further 16 AED have the potential for pharmacodynamic or pharmacokinetic DDI, but no data regarding DOAC are available. For the remaining 17 AED it is unknown if they have DDI with DOAC.

EXPERT OPINION

Knowledge about pharmacokinetic and pharmacodynamic DDI of AED and DOAC is limited and frequently restricted to in vitro and in vivo findings. Since no data about DDI with DOAC are available for 67% of AED and an increasing number of patients have a combined medication of DOAC and AED, there is an urgent need for research on this topic.

The Effect of Levetiracetam Compared with Enzyme-Inducing Antiseizure Medications on Apixaban and Rivaroxaban Peak Plasma Concentrations

BACKGROUND AND OBJECTIVE

Post-stroke epilepsy represents an important clinical challenge as it often requires both treatment with direct oral anticoagulants (DOACs) and antiseizure medications (ASMs). Levetiracetam (LEV), an ASM not known to induce metabolizing enzymes, has been suggested as a safer alternative to enzyme-inducing (EI)-ASMs in patients treated with DOACs; however, current clinical guidelines suggest caution when LEV is used with DOACs because of possible P-glycoprotein induction and competition (based on preclinical studies). We investigated whether LEV affects apixaban and rivaroxaban concentrations compared with two control groups: (a) patients treated with EI-ASMs and (b) patients not treated with any ASM.

METHODS

In this retrospective observational study, we monitored apixaban and rivaroxaban peak plasma concentrations (Cmax) in 203 patients treated with LEV (n = 28) and with EI-ASM (n = 33), and in patients not treated with any ASM (n = 142). Enzyme-inducing ASMs included carbamazepine, phenytoin, phenobarbital, primidone, and oxcarbazepine. We collected clinical and laboratory data for analysis, and DOAC Cmax of patients taking LEV were compared with the other two groups.

RESULTS

In 203 patients, 55% were female and the mean age was 78 ± 0.8 years. One hundred and eighty-six patients received apixaban and 17 patients received rivaroxaban. The proportion of patients with DOAC Cmax below their therapeutic range was 7.1% in the LEV group, 10.6% in the non-ASM group, and 36.4% in the EI-ASM group (p < 0.001). The odds of having DOAC Cmax below the therapeutic range (compared with control groups) was not significantly different in patients taking LEV (adjusted odds ratio 0.70, 95% confidence interval 0.19-2.67, p = 0.61), but it was 12.7-fold higher in patients taking EI-ASM (p < 0.001). In an analysis in patients treated with apixaban, there was no difference in apixaban Cmax between patients treated with LEV and non-ASM controls, and LEV clinical use was not associated with variability in apixaban Cmax in a multivariate linear regression.

CONCLUSIONS

In this study, we show that unlike EI-ASMs, LEV clinical use was not significantly associated with lower apixaban Cmax and was similar to that in patients not treated with any ASM. Our findings suggest that the combination of LEV with apixaban and rivaroxaban may not be associated with decreased apixaban and rivaroxaban Cmax. Therefore, prospective controlled studies are required to examine the possible non-pharmacokinetic mechanism of the effect of the LEV-apixaban or LEV-rivaroxaban combination on patients' outcomes.

Effect of drug interactions with non-vitamin-K oral anticoagulants on thromboembolic events in patients with nonvalvular atrial fibrillation

Introduction

Few real-world studies have investigated drug-drug interactions (DDIs) involving non-vitamin-K antagonist oral anticoagulants (NOACs) in patients with nonvalvular atrial fibrillation (NVAF). The interactions encompass drugs inducing or inhibiting cytochrome P450 3A4 and permeability glycoprotein. These agents potentially modulate the breakdown and elimination of NOACs. This study investigated the impact of DDIs on thromboembolism in this clinical scenario.

Method

Patients who had NVAF and were treated with NOACs were selected as the study cohort from the National Health Insurance Research Database of Taiwan. Cases were defined as patients hospitalised for a thromboembolic event and who underwent a relevant imaging study within 7 days before hospitalisa-tion or during hospitalisation. Each case was matched with up to 4 controls by using the incidence density sampling method. The concurrent use of a cytochrome P450 3A4/permeability glycoprotein inducer or inhibitor or both with NOACs was identified. The effects of these interactions on the risk of thromboembolic events were examined with univariate and multivariate conditional logistic regressions.

Results

The study cohort comprised 60,726 eligible patients. Among them, 1288 patients with a thromboembolic event and 5144 matched control patients were selected for analysis. The concurrent use of a cytochrome P450 3A4/permeability glycoprotein inducer resulted in a higher risk of thromboembolic events (adjusted odds ratio [AOR] 1.23, 95% confidence interval [CI] 1.004-1.51).

Conclusion

For patients with NVAF receiving NOACs, the concurrent use of cytochrome P450 3A4/ permeability glycoprotein inducers increases the risk of thromboembolic events.

Effectiveness and Safety of Different Oral Anticoagulants with P-glycoprotein/ CYP3A4 Inhibitors: A Network Meta-analysis

BACKGROUND

Metabolism of oral anticoagulants (OAC) is affected by P-glycoprotein (P-gp)/ CYP3A4 enzyme. However, the P-gp/CYP3A4 inhibitors are unavoidably used with OACs.

METHODS

Medline, Cochrane, and Embase were systematically searched for randomized controlled trials and cohort studies from inception till 23rd November, 2022 to assess the safety and effectiveness of OACs when concomitantly used with P-gp/CYP3A4 inhibitors. The primary outcomes were major bleeding and gastrointestinal (GI) bleeding. Secondary outcomes were stroke/systemic embolism (SE), all-cause mortality, any bleeding as well as intracranial hemorrhage (ICH). We estimated summary odds ratios (OR) with 95% credible intervals (CI) using pairwise and network meta-analysis with random effects.

RESULTS

A total of 11 studies involving 37,973 patients were included. When concomitantly used with P-pg/ CYP3A4 inhibitors, network meta-analysis indicated that dabigatran, apixaban, and edoxaban were associated with significantly lower risk of major bleeding compared to rivaroxaban, with ORs of 0.56, 0.51 and 0.48, respectively. Rivaroxaban and dabigatran were associated with a significantly increased risk of GI bleeding than warfarin, apixaban and edoxaban. Dabigatran and apixaban were linked with significantly lower risk of any bleeding compared with warfarin (ORs were 0.75 and 0.68, respectively) or rivaroxaban (ORs were 0.67 and 0.60, respectively). Apixaban (OR 0.32) and edoxaban (OR 0.35) were associated with a lower risk of ICH compared with warfarin. There was no difference between any OACs in terms of stroke/SE or all-cause mortality.

CONCLUSION

When concomitantly used with P-gp/CYP3A4 inhibitors, apixaban and edoxaban were associated with a lower risk of bleeding, though no significant difference in effectiveness was observed among all OACs.

Levetiracetam Interaction with Direct Oral Anticoagulants: A Pharmacovigilance Study

BACKGROUND

Levetiracetam is widely used in post-stroke epilepsy. However, it is suspected to possess P-glycoprotein (P-gp) induction properties, and therefore, a potentially significant interaction with direct oral anticoagulants (DOACs). We aimed to search for ischemic stroke signals with levetiracetam and the DOACs.

METHODS

In this retrospective pharmacovigilance study, we used the FAERS database to identify ischemic stroke events associated with DOACs and concomitant use of levetiracetam. We evaluated disproportionate reporting by the adjusted reporting odds ratio (adjROR) and the lower bound of the shrinkage 95% confidence interval. When shrinkage is positive, an increased risk of a specific adverse event occurrence is emphasized over the sum of the individual risks when these same drugs are used separately.

RESULTS

We identified 1841 (1.5%), 3731 (5.3%), 338 (4.9%), and 1723 (1.3%) ischemic stroke reports with apixaban, dabigatran, edoxaban, and rivaroxaban, respectively. The adjROR of the interaction effect was 3.57 (95% CI 2.81-4.58) between DOACs and levetiracetam. The shrinkage analysis detected an interaction between each of the DOACs and levetiracetam. The logistic model and shrinkage analysis failed to detect an interaction when queried for hemorrhagic stroke. A significant signal in the classical enzyme inducer, carbamazepine, strengthened our results (adjROR; 8.47, 95% CI 5.37-13.36).

CONCLUSIONS

Our study shows a strong signal for the levetiracetam interaction with the DOACs. Our findings suggest implementation of a drug monitoring strategy.

Non-vitamin K Antagonist Oral Anticoagulants (NOACs) Versus Warfarin in Patients with Atrial Fibrillation Using P-gp and/or CYP450-Interacting Drugs: a Systematic Review and Meta-analysis

PURPOSE

Non-vitamin K antagonist oral anticoagulants (NOACs) are excreted by P-glycoprotein (P-gp) and some are metabolized by CYP450 enzymes such as CYP3A4. Although fewer drug interactions are present with NOACs, it is unclear whether NOACs should also be preferred over vitamin K antagonists (VKAs) in patients with atrial fibrillation (AF) using pharmacokinetically interacting drugs. Therefore, the benefit-risk profile of NOACs versus VKAs was investigated in AF patients treated with P-gp and/or CYP450-interacting drugs.

METHODS

Using PubMed and Embase, randomized controlled trials and observational studies on the effectiveness and safety of NOACs versus VKAs in AF patients using P-gp and/or CYP450-interacting drugs were included. A meta-analysis was performed, calculating relative risks (RR) and 95% confidence intervals (CI) with the Mantel-Haenszel method.

RESULTS

Twelve studies were included, investigating 10,793 NOAC and 10,096 VKA users treated with P-gp/CYP3A4 inhibitors, whereas no studies on P-gp and/or CYP450-inducing drugs were identified. Compared to VKAs, NOACs were associated with a borderline non-significantly lower stroke or systemic embolism (stroke/SE) risk (RR 0.85, 95%CI (0.72-1.01)), significantly lower intracranial bleeding (RR 0.47, 95%CI (0.34-0.65)) and all-cause mortality risks (RR 0.87, 95%CI (0.79-0.95), but significantly higher gastrointestinal bleeding risk (RR 1.74, 95%CI (1.06-2.86)). Among AF patients using amiodarone, NOACs were associated with significantly lower stroke/SE (RR 0.71, 95%CI (0.54-0.93)) and intracranial bleeding risks (RR 0.51, 95%CI (0.29-0.88)), but significantly higher gastrointestinal bleeding risk (RR 2.15, 95%CI (1.24-3.72)) than VKAs.

CONCLUSION

The benefit-risk profile of NOACs compared to VKAs was preserved in AF patients using P-gp/CYP3A4 inhibitors, including amiodarone.

Drug-drug interactions with direct oral anticoagulants for the prevention of ischemic stroke and embolism in atrial fibrillation: a narrative review of adverse events

INTRODUCTION

In randomized trials, direct oral anticoagulants (DOAC) were non-inferior to the vitamin-K-antagonist (VKA) warfarin in preventing stroke/embolism in patients with atrial fibrillation (AF). DOAC are substrates for P-glycoprotein (P-gp), CYP3A4 and CYP2C9. The activity of these enzymes is modulated by several drugs which might induce pharmacokinetic drug-drug interactions (DDI). Drugs affecting platelet function have the potential for pharmacodynamic DDI of DOAC.

AREAS COVERED

The literature was searched for: 'dabigatran,' 'rivaroxaban,' 'edoxaban,' or 'apixaban' and drugs affecting platelet function, CYP3A4-, CYP2C9- or P-gp-activity. Reports about bleeding and embolic events attributed to DDI with DOAC in AF-patients were found for 43 of 171 drugs with interacting potential (25%), most frequently with antiplatelet and nonsteroidal anti-inflammatory drugs. Whereas a co-medication of platelet-affecting drugs is invariably reported to increase the bleeding risk, the findings regarding P-gp-, CYP3A4- and CYP2C9- activity-affecting drugs are ambiguous.

EXPERT OPINION

Tests for plasma DOAC-levels and information about DDI of DOAC should be widely available and user-friendly. If advantages and disadvantages of DOAC and VKA can be investigated exhaustively, individualized anticoagulant therapy can be offered to patients, considering co-medication, comorbidities, genetic and geographic factors and the health care system.

Interactions Between Direct Oral Anticoagulants (DOACs) and Antiseizure Medications: Potential Implications on DOAC Treatment

The use of direct oral anticoagulants (DOACs) is increasing because of their superior efficacy and safety compared with vitamin K antagonists. Pharmacokinetic drug interactions, particularly those involving cytochrome P450- mediated metabolism and P-glycoprotein transport, significantly affect the efficacy and safety of DOACs. In this article, we assess the effects of cytochrome P450- and P-glycoprotein-inducing antiseizure medications on DOAC pharmacokinetics in comparison to rifampicin. Rifampicin decreases to a varying extent the plasma exposure (area under the concentration-time curve) and peak concentration of each DOAC, consistent with its specific absorption and elimination pathways. For apixaban and rivaroxaban, rifampicin had a greater effect on the area under the concentration-time curve than on peak concentration. Therefore, using peak concentration to monitor DOAC concentrations may underestimate the effect of rifampicin on DOAC exposure. Antiseizure medications that are cytochrome P450 and P-glycoprotein inducers are commonly used with DOACs. Several studies have observed a correlation between the concomitant use of DOACs and enzyme-inducing antiseizure medications and DOAC treatment failure, for example, ischemic and thrombotic events. The European Society of Cardiology recommends avoiding this combination, as well as the combination of DOACs with levetiracetam and valproic acid, owing to a risk of low DOAC concentrations. However, levetiracetam and valproic acid are not cytochrome P450 or P-glycoprotein inducers, and the implications of their use with DOACs remain to be elucidated. Our comparative analysis suggests DOAC plasma concentration monitoring as a possible strategy to guide dosing owing to the predictable correlation between DOACs' plasma concentration and effect. Patients taking concomitant enzyme-inducing antiseizure medications are at risk for low DOAC concentrations and subsequently, treatment failure and thus can benefit from DOAC concentration monitoring to prophylactically identify this risk.

Bleeding events among patients concomitantly treated with direct oral anticoagulants and macrolide or fluoroquinolone antibiotics

Fluoroquinolones and macrolides may, due to a potential drug-drug interaction, increase the concentration of any concomitantly administered direct oral anticoagulant (DOAC) and thereby increase the risk of severe bleeding. However, clinical evidence for such an effect is scarce. The present study aimed to evaluate the association between the use of fluoroquinolones or macrolides and bleeding events in patients with concomitant DOAC use. This was a nationwide cohort study including 19 288 users of DOACs in 2008-2018 using information from Swedish national health registers. We compared the incidence of bleeding events associated with use of fluoroquinolones or macrolides using doxycycline as a negative control. Cox regression was used to calculate crude and adjusted hazard ratios (aHRs) in time windows of various length of follow-up after the start of antibiotic use. The incidence rates for fluoroquinolones and macrolides ranged from 12 to 24 and from 12 to 53 bleeding events per 100 000 patients in the investigated time windows. The aHRs (95% confidence interval) for use of fluoroquinolones and macrolides were 1.29 (0.69-2.44) and 2.60 (0.74-9.08) at the concomitant window, 1.31 (0.84-2.03) and 1.79 (0.75-4.29) at 30 days, and 1.34 (0.99-1.82) and 1.28 (0.62-2.65) at 150 days, respectively. With regard to fluoroquinolones, the present study suggests that the risk of bleeding when combined with DOACs, if any, is small. Codispensation of macrolides in patients on DOACs was not associated with an increased risk of bleeding. However, due to the small number of macrolide users, the results must be interpreted with caution.

Effectiveness and Safety of Lacosamide, A Third-generation Anti-seizure Medication, for Poststroke Seizure and Epilepsy: A Literature Review

Advances in stroke treatment have resulted in a dramatic reduction in stroke mortality. Nevertheless, poststroke seizures and epilepsy are issues of clinical importance affecting survivors. Additionally, stroke is the most common cause of epilepsy in older adults. Although numerous antiseizure medications exist, studies are needed to provide robust evidence of the efficacy and tolerability of these medicines for treating poststroke seizures and epilepsy. Crucially, the newer generations of antiseizure medications require testing. Lacosamide, a third-generation antiseizure medication approved for treating localization-related epilepsy, has a novel mechanism of selectively enhancing the slow inactivation of sodium channels. This literature review evaluated whether lacosamide is effective and safe for the treatment of poststroke seizures and epilepsy. This review critically analyzed studies published in major academic databases (Pubmed, Embase, and Cochrane Library) from inception through June 2022 regarding the interaction of lacosamide with poststroke seizures and epilepsy. We included clinical prospective, retrospective, and case studies on patients with poststroke seizure and epilepsy, lacosamide as a treatment for seizures, neuroprotection in animal models of seizures, and the safety of lacosamide when coadministering anticoagulants. Clinical studies revealed lacosamide to be an effective antiseizure medication with high efficacy and tolerability in patients with poststroke seizures and epilepsy. In animal models, lacosamide proved effective at seizure reduction and neuroprotection. Pharmacokinetic studies demonstrated the safety of lacosamide when coadministering conventional and new anticoagulants. The literature suggests that Lacosamide is a promising candidate antiseizure medication for patients with poststroke seizures and epilepsy.

Discharge status validation of the Chang Gung Research database in Taiwan

BACKGROUND

The Chang Gung Research Database (CGRD) is the largest multi-institutional electronic medical records database in Taiwan and has been widely used to establish evidence studies. However, the accuracy of CGRD has rarely been validated. This study aims to validate the discharge status, especially with a focus on mortality, of admission data under CGRD.

METHODS

We constructed an observational study using CGRD linked with TDR to validate the discharge status. The CGRD and TDR data were obtained from the Chang Gung Memorial Hospital system and the Health and Welfare Data Science Center, respectively. The accuracy, positive predictive value (PPV), and underestimated mortality rate (UEM) were employed as indicators for validation. Year, sex, age, and the primary cause for admission (PCA) were analyzed.

RESULTS

A total of 1,972,044 admission records under CGRD were analyzed. The overall accuracy for mortality coding on discharge status was higher than 97% within one week after discharge. The accuracy increased by year and was more than 98% after 2010. A similar result was observed in UEM; the UEM within one week was lower than 10% after 2010. These indicators varied by age group and PCA-elderly patients had relatively lower accuracy and higher UEM (approximately 11%). The presence of UEM within one week was better but varied by disease.

CONCLUSIONS

Considering the data accuracy and UEM discharge status, prioritizing the use of inpatient data after 2010 under CGRD for mortality outcome follow-up studies is recommended.

Direct oral anticoagulants for the treatment of atrial fibrillation in patients with hematologic malignancies

Atrial fibrillation (AF) is common in patients with cancer due to both the proinflammatory effect of neoplastic cells and to cardiotoxicity of anti-tumor therapies. Anticoagulation is still challenging in cancer patients due to increased bleeding risk related to specific neoplasms such us hematologic malignancies. The aim of this retrospective study was to evaluate the safety and the efficacy of direct oral anticoagulants (DOACs) in AF patients affected by hematologic neoplasms. We included 97 patients on active anticancer treatment. The median follow-up was 25 months (range 10-108). No thromboembolic complications occurred, while 14 bleeding events were recorded: 1 major, 12 clinical relevant non major bleeding and 1 minor bleeding. Although retrospective and with a small number of enrolled patients, our data support the efficacy and safety of DOACs in patients affected by hematologic malignancies suggesting caution to particular situations, such as thrombocytopenia.

Major Bleeding Risk in Atrial Fibrillation Patients Co-Medicated With Non-Vitamin K Oral Anticoagulants and Antipsychotics

Major bleeding risks associated with non-vitamin K oral anticoagulants (NOACs) used with and without concurrent antipsychotics in patients with non-valvular atrial fibrillation (AF) were assessed. A total of 98,863 patients with non-valvular AF receiving at least one NOAC prescription from Taiwan’s National Health Insurance database were enrolled. Major bleeding was defined as a primary diagnosis of intracranial or gastrointestinal hemorrhage or bleeding at other sites. The adjusted incidence rate difference (AIRD) per 1,000 person-years and adjusted rate ratio of major bleeding were estimated using Poisson regression and inverse probability of treatment weighting using the propensity score. A total of 8,037 major bleeding events occurred during 705,521 person-quarters with NOAC prescriptions. Antipsychotics were used in 26.35% of NOAC-exposed patients. Compared to using NOAC alone, co-medication of either typical (AIRD: 79.18, 95% confidence interval [CI]: 70.63–87.72) or atypical (AIRD: 40.5, 95% CI: 33.64–47.35) antipsychotic with NOAC had a significant increase in the adjusted incidence rate per 1,000 person-years of major bleeding. The concomitant use of a NOAC with chlorpromazine (AIRD: 103.87, 95% CI: 51.22–156.52), haloperidol (AIRD: 149.52, 95% CI: 125.03–174.00), prochlorperazine (AIRD: 90.43, 95% CI: 78.55–102.32), quetiapine (AIRD: 44.6, 95% CI: 37.11–52.09), or risperidone (AIRD: 41.55, 95% CI: 22.86–60.24) (All p < 0.01) showed a higher adjusted incidence rate of major bleeding than using NOACs alone. The concomitant use of typical (chlorpromazine, haloperidol, or prochlorperazine) or atypical (quetiapine or risperidone) antipsychotic with NOACs was associated with a significantly increased risk of major bleeding.

Relevant pharmacologic interactions in the concurrent management of brain tumor-related epilepsy and venous thromboembolism: a systematic review

INTRODUCTION

Co-administration of direct oral anticoagulants (DOACs) with antiepileptic drugs (AEDs) is increasingly common in brain tumor patients. We therefore performed a systematic review of the current evidence for potential drug interactions between DOACs and AEDs in this patient population.

METHODS

We conducted a systematic review of the literature via PubMed according to PRISMA guidelines (last accessed December 15, 2021). Included were clinical studies and case reports, written in English language and published between 2010 and 2021, that investigated concurrent clinical use of AEDs with DOACs for any indication. Non-English articles, articles not related to our research question, review articles and commentaries were excluded. Full-text articles were evaluated for possible confounding factors and results were summarized using a data table highlighting the key characteristics of each article.

RESULTS

We identified a total of 122 unique articles, of which 27 were deemed relevant to our research question. Of these, 8 articles were clinical studies (n = 295,415 patients) and 19 were case reports (n = 25 patients). Only 3 clinical studies and 2 case reports reported interactions between AEDs and DOACs in patients with active cancer and none reported interactions in patients with brain tumors.

CONCLUSION

We have identified low (class IV) level evidence of potential drug interactions between DOACs and AEDs. Even though there is no current report of interactions in brain tumor patients, neuro-oncology providers should be aware of the emerging evidence regarding drug interactions between DOACs and AEDs and take this into consideration when concurrently prescribing these to patients.

Impact of P-glycoprotein and/or CYP3A4-interacting drugs on effectiveness and safety of NOACs in patients with atrial fibrillation: a meta-analysis

AIM

P-glycoprotein (P-gp) and CYP3A4-interacting drugs influence plasma levels of non-vitamin K antagonist oral anticoagulants (NOACs). However, the clinical relevance is questioned. Therefore, the impact of pharmacokinetically-interacting drugs on the effectiveness and safety of NOACs in patients with atrial fibrillation (AF) was investigated.

METHODS

A meta-analysis was performed based on randomized controlled trials and observational studies retrieved from Pubmed and Embase, that investigated the impact of concomitantly used P-gp/CYP3A4-interacting drugs on the risk-benefit profile of NOACs in AF patients.

RESULTS

Fifteen studies were included, investigating 21,711 and 306,421 NOAC-treated AF patients with and without P-gp/CYP3A4 inhibitor use respectively, while only one study included P-gp/CYP3A4 inducers. In NOAC-treated AF patients, concomitant use of P-gp/CYP3A4 inhibitors was associated with significantly higher major bleeding (relative risk (RR) 1.10, 95% confidence interval (CI) (1.01-1.19)) and all-cause mortality risks (RR 1.14, 95%CI (1.05-1.23)) compared to not using P-gp/CYP3A4 inhibitors, while the risks of stroke/SE (RR 0.88, 95%CI (0.77-1.01)), intracranial bleeding (RR 0.89, 95%CI (0.68-1.15)) and gastro-intestinal bleeding (RR 1.09, 95%CI (0.91-1.30)) were not significantly different. Concomitant use of amiodarone with NOACs was associated with lower thromboembolic (RR 0.75, 95%CI (0.61-0.92)), similar major bleeding (RR 0.92, 95%CI (0.80-1.07)), but higher mortality risks (RR 1.21, 95%CI (1.05-1.39)). Co-administration of verapamil or diltiazem was associated with higher major bleeding risks (RR 1.64, 95%CI (1.31-2.06)), but comparable thromboembolic (RR 1.10, 95%CI (0.75-1.61)) and mortality risks (RR 1.01, 95%CI (0.77-1.33)).

CONCLUSION

Given the higher bleeding and mortality risks in NOAC-treated AF patients concomitantly using P-gp/CYP3A4 inhibitors, close monitoring is warranted.

Major Bleeding Risk in Patients With Non-valvular Atrial Fibrillation Concurrently Taking Direct Oral Anticoagulants and Antidepressants

Direct oral anticoagulants (DOACs) are commonly prescribed with antidepressants that may increase bleeding risk. Here we assessed the association between DOACs with and without concurrent antidepressants and major bleeding risk in patients with atrial fibrillation (AF) by a retrospective cohort study included patients with AF who received prescriptions of DOACs in Taiwan’s National Health Insurance database between 2012 and 2017. Adjusted rate ratio (ARR) of major bleeding was calculated by comparing incidence rate adjusted with Poisson regression and inverse probability of treatment weighting using the propensity score between patient-times with and without antidepressants. Among 98863 patients with AF, concurrent use of bupropion with DOACs increased the risks of all major bleeding (ARR: 1.49, 95% CI: 1.02–2.16) and gastrointestinal hemorrhage (ARR: 1.57, 95% CI: 1.04–2.33). An increased risk of intracerebral hemorrhage (ICH) was associated with the combinations of DOACs with selective serotonin reuptake inhibitors (SSRIs, ARR: 1.38, 95% CI: 1.08–1.76), particularly in paroxetine (ARR: 2.11, 95% CI: 1.17–3.81), and tetracyclic antidepressants (TeCAs, ARR: 1.34, 95% CI: 1.01–1.78). In subgroup analyses stratified by individual NOACs, SSRIs increased the risk of ICH in the dabigatran-treated patients (ARR: 1.55, 95% CI: 1.04–2.33). The combinations of apixaban and serotonin-norepinephrine reuptake inhibitors (SNRIs) were associated with a higher risk of all major bleeding (ARR: 1.63, 95% CI: 1.04–2.55). These results clearly indicate the drug–drug interactions between DOACs and antidepressants, which should be carefully considered when prescribing DOACs in adult patients. Careful monitoring for bleeding should be performed while concurrently prescribing DOACs with bupropion, SSRI, SNRI, and TeCA. Concomitant use of DOACs and TCAs may be a relatively safe strategy for patients with AF.

Carbamazepine, phenytoin, and oral anticoagulants: Drug-drug interaction and clinical events in a retrospective cohort

BACKGROUND

Carbamazepine and phenytoin are potent inducers of enzymes that metabolize oral anticoagulants.

OBJECTIVES

To determine the clinical impact of drug-drug interactions between these anticonvulsants and oral anticoagulants, and whether they affect the treatment with direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs).

MATERIAL AND METHODS

Data on patients cotreated with carbamazepine or phenytoin and an oral anticoagulant were retrospectively retrieved from medical records from 2011 to 2020. Outcomes were time in therapeutic range (TTR), DOAC levels, thromboembolic events, major bleeding, and all-cause mortality.

RESULTS

Among 85 patients (37% female, median age 68 years) treated with carbamazepine (n = 43 [51%]) or phenytoin (n = 42 [49%]), 53 (62%) were initially treated with VKAs and 32 (38%) with DOACs. TTR in VKA patients was 63%, which improved in year 2. Four of seven trough and five of 12 peak DOAC plasma levels were lower than expected. The incidence rate (95% confidence interval) per 100 person-years for thromboembolism was 3.6 (3.1-4.2) for VKA patients and 4.4 (3.5-5.6) for DOAC patients; for major bleeding 1.8 (1.5-2.1) and 1.5 (1.2-1.9), and for all-cause mortality 3.6 (3.1-4.2) and 1.5 (1.2-1.9), respectively. Incidence rates between VKAs and DOACs and between carbamazepine and phenytoin were similar.

CONCLUSION

There was a high incidence of thromboembolism in patients cotreated with anticoagulants and carbamazepine or phenytoin. The incidence rates of thrombotic and bleeding events were similar between VKA and DOAC patients. DOAC levels were lower than expected in 47% of cases tested, without correlation with clinical outcomes.

Non-vitamin K Antagonist Oral Anticoagulants and Drug-Food Interactions: Implications for Clinical Practice and Potential Role of Probiotics and Prebiotics

Non-vitamin K antagonist oral anticoagulants (NOACs) are a therapeutic option to prevent stroke in patients with atrial fibrillation (AF). In fact, NOACs have become the recommended choice by international clinical practice guidelines over vitamin K antagonists (VKA), because of their efficacy and safety profile, especially in newly initiated patients. The more predictable pharmacokinetic and pharmacodynamic profile of this family of drugs allows preventing anticoagulation drug monitoring. Furthermore, NOACs have significantly fewer drug and food interactions in comparison with VKAs. Despite this, there are no studies that compare the effects on the quality of anticoagulation of NOACs with the intake of potential interactions drugs of P-glycoprotein and cytochrome P450 (CYP). This review brings an overview of NOACs pharmacokinetics profile and their potential drug-food interactions. We also briefly discuss the potential role of prebiotics and probiotics in patients under therapy with NOACs.

Risk of major bleeding associated with concomitant use of anticancer drugs and direct oral anticoagulant in patients with cancer and atrial fibrillation

This study evaluated the risk of major bleeding associated with concomitant use of direct oral anticoagulant (DOAC) and anticancer drugs (ACDs), which share metabolic pathways, in patients with atrial fibrillation (AF) and cancer. We performed a retrospective cohort study using Taiwan's National Health Insurance database and included patients with AF and cancer who received DOAC prescriptions from 1 to 2012 to 31 December 2017. The incidence of major bleeding in person-quarters with concomitant use of DOAC and any of 15 ACDs with inhibitory or competitive effects of CYP3A4 or P-gp activity (docetaxel, vinorelbine, methotrexate, irinotecan, etoposide, doxorubicin, cyclophosphamide, imatinib, nilotinib, abiraterone, bicalutamide, tamoxifen, anastrozole, cyclosporine, tacrolimus) was compared with that in person-quarters with DOAC alone. Adjusted incidence-rate differences between DOAC use with and without concurrent ACDs were estimated using Poisson regression models weighted by the inverse probability of treatment. In 13,158 patients with AF and cancer (76.9 ± 8.9 years; male 60%), 1545 major bleeding events occurred during 90,540 DOAC-exposed person-quarters. Concurrent use of DOAC and any of 15 ACDs occurred in only 18% of patients. Compared with use of DOAC alone, concomitant use of DOAC and these ACDs was not associated with an increased risk of major bleeding. Co-medication with DOAC and ACDs with inhibitory or competitive effects on CYP3A4 or P-gp activity was not associated with a higher risk of major bleeding than DOAC alone. Our findings may provide clinicians with confidence regarding the safety of concurrent use of DOAC and ACDs in patients with AF and cancer.

Hypoglycemia Associated With Drug-Drug Interactions in Patients With Type 2 Diabetes Mellitus Using Dipeptidylpeptidase-4 Inhibitors

Background: Dipeptidylpeptidase-4 inhibitors (DPP-4i′s) are considered to be safe for patients with type 2 diabetes mellitus (T2DM). However, little is known about drug–drug interactions between DPP-4i′s and concurrent medications.

Methods: Data on patients using DPP-4i′s for T2DM during 2011–2017 were retrieved from Chang Gung Research database provided by Chang Gung Memorial Hospital. Patients were excluded if they were aged <30 years or >90 years; had incomplete demographic data; had insulinoma; or had records of concomitant insulin use. A generalized estimating equation–based Poisson model was employed for statistical analysis. The primary outcome was hypoglycemia events.

Results: We retrieved data on a total of 97,227 patients using DPP-4i′s. After patients were excluded according to the mentioned criteria, the remaining 77,047 DPP-4i users were studied (mean age 64 ± 12 years, men 54.4%). The most common medications coprescribed with DPP4is over all person-quarters were acetaminophen, simvastatin, fluvastatin, and colchicine (all >20,000 person-quarters). The combinations of a DPP-4i with bumetanide, captopril, colchicine, acetaminophen, cotrimoxazole, and pantoprazole were associated with an increased risk of hypoglycemia. Compared with the ratios observed for person-quarters of DPP-4i use alone (reference category), the adjusted prevalence ratios per 100 person-years of hypoglycemia for person-quarters of DPP-4i use in combination with bumetanide, captopril, colchicine, acetaminophen, cotrimoxazole, and pantoprazole were 2.44 (95% confidence interval [CI], 1.78–3.36), 2.97 (95% CI, 2.26–3.90), 1.87 (95% CI, 1.44–2.42), 2.83 (95% CI, 2.44–3.29), 2.27 (95% CI, 1.27–4.04), and 3.03 (95% CI, 1.96–4.68), respectively.

Conclusion: Among patients taking DPP-4i′s for T2DM, concurrent use of such inhibitors with bumetanide, captopril, acetaminophen, and pantoprazole was associated with an increased risk of hypoglycemia compared with the use of DPP-4i′s alone. Physicians prescribing DPP-4i′s should consider the potential risks associated with their concomitant use with other drugs.

Concomitant Use of Direct Oral Anticoagulants and Antiepileptic Drugs: A Prospective Cohort Study in Patients with Atrial Fibrillation

BACKGROUND

European guidelines do not recommend the use of carbamazepine, levetiracetam, phenobarbital, phenytoin, topiramate and valproic acid in patients taking direct oral anticoagulants (DOACs). Little is known regarding the clinical relevance of the interaction between DOACs and antiepileptic drugs.

OBJECTIVES

To evaluate the incidence of thromboembolic and bleeding events in patients with non-valvular atrial fibrillation (AF) concurrently treated with DOACs and antiepileptic drugs.

METHODS

This is a prospective multicentre cohort study of patients with non-valvular AF concurrently treated with DOACs and antiepileptic drugs. The primary outcome was ischaemic stroke/transient ischaemic attack (TIA)/systemic embolism (SE). Secondary outcome was major bleeding (MB). Incidence rates (% patient-year) were evaluated for the study outcomes.

RESULTS

Overall, 91 patients were included. Mean age was 78 ± 9.5 years, 49.5% were female. Mean CHA₂DS₂-VASc score was 4.76 ± 1.59 and mean HAS-BLED was 2.67 ± 1.26. Overall, 41, 20, 11, 10 and 9 out of 91 patients were treated with levetiracetam, valproic acid, phenobarbital, carbamazepine and other antiepileptic drugs, respectively. During a median follow-up of 17.5 ± 14.5 months, stroke/TIA/SE occurred in 9 patients (5.7% patient-year) and MB in 3 patients (1.9% patient-year). Ischaemic stroke was fatal in 3 patients (1.9% patient-year) and MB in one patient (0.6% patient-year).

CONCLUSION

In this cohort, patients with non-valvular AF treated with DOACs and antiepileptic drugs appear to have a relatively high rate of thromboembolic events.