The Clinical Significance of Drug-Food Interactions of Direct Oral Anticoagulants

Decision model to evaluate the cost of clinical events associated with switching from apixaban to rivaroxaban among patients with non-valvular atrial fibrillation in the United States and Germany

AIMS

Direct-acting oral anticoagulants (DOACs) have emerged as the preferred treatment for nonvalvular atrial fibrillation (NVAF). However, evidence concerning the economic outcomes of DOAC switching remains limited. This study aimed to assess the economic outcomes of DOAC switching in the US and Germany, two countries with a high AF prevalence and DOAC utilization.

METHODS

A decision model was developed to assess the incidence and cost of stroke/systemic embolism (SE) and major bleeding (MB) associated with switching from apixaban to rivaroxaban in patients with NVAF. The model compared two scenarios: continuers (patients continuing apixaban) and switchers (patients switching from apixaban to rivaroxaban). Model inputs on clinical event rates were sourced from a published real-world study, cost inputs were from a standard costing database and published literature. The analysis was conducted over a 1-year time horizon from US Medicare fee-for-service and German public healthcare payer perspectives.

RESULTS

Over one year, 47,036 patients among a hypothetical plan size of 1,000,000 US Medicare fee-for-service members and 1,019,079 patients among the German adult population size of 70,107,122 were estimated to be treated for NVAF with apixaban. Switching all patients from apixaban to rivaroxaban resulted in 1,498 and 32,447 additional clinical events (stroke/SE and MB) and deaths in the US and Germany, respectively, compared to continuing with apixaban. This led to a total incremental cost of $17.3 million and €153 million from Medicare fee-for-service and German public healthcare perspectives, respectively.

LIMITATIONS

The incidence and hazard ratios of clinical events informing this analysis were based on a US commercial and Medicare Advantage population and may not be generalizable to other populations.

CONCLUSIONS

Switching from apixaban to rivaroxaban was associated with increased clinical events, deaths, and higher medical care costs, potentially representing a less favorable strategy economically compared to continuing apixaban among patients with NVAF.

Direct oral anticoagulant failure in patients with venous thromboembolism-why and what next?

Management of recurrent thrombotic events in patients taking a direct oral anticoagulant can be challenging. In this review, we consider causes of so-called direct oral anticoagulant failure, from poor adherence, malabsorption, and drug interactions to the presence of undiagnosed antiphospholipid syndrome, cancer-associated thrombosis, severe thrombophilia, vasculitis, and other rare causes. We discuss the known or potential pathogenesis of venous thromboembolism recurrence in these situations and provide practical guidance to assist clinicians faced with these challenging cases.

Assessment of Risk Factors for Atrial Fibrillation With a Particular Focus on Echocardiographic Parameters, in Patients With Acute Myocardial Infarction

BACKGROUND

Atrial fibrillation is the most common arrhythmia worldwide, affecting between 2% and 4% of population. The projected further progression is a reason to consider AF as a global epidemic problem. The efficiency in diagnosing new cases is still unsatisfactory.

METHODS

The prospective study included 74 patients hospitalized for acute myocardial infarction. Echocardiography with advanced assessment of the left atrium was performed on all patients. R Statistical Software was used for statistical and graphical processing.

RESULTS

Atrial fibrillation was first diagnosed in 13.5% of patients with acute myocardial infarction, and in 5.4% of the patients the diagnosis was made during the long-term follow-up period. Analysis of the data collected showed that patients with arrythmia were older (71.79 vs 63.5 years; p = 0.047), had a higher BMI (30.15 vs 26.76 kg/m2; p = 0.039) and had a higher CHA2DS2 VASc score (4.14 vs 3.02 points). Among the echocardiographic parameters, those that significantly differentiated patients with arrythmia included larger LA area (21.62 vs 18.84 cm2; p = 0.027), lower LAEF 4CH (43.46 vs 55.93%; p = 0.029), lower LAEF mean (44.08 vs 55.63%; p = 0.014), lower EI (1.03 vs 1.49; p = 0.032), lower LASr 4CH (19.08 vs 26.72%; p = 0.020), lower LASr mean (18.62 vs 26.73%; p = 0.009), higher E/e' (12.62 vs 9.58; p = 0.01), higher LASI (0.95 vs 0.45; p = 0.016).

CONCLUSIONS

Among the echocardiographic parameters, those that may indicate an increased risk of atrial fibrillation and could be implemented in clinical practice are LASr and LASI. Determining them in risk profiling and the implementation of individualized arrhythmia detection methods could increase diagnostic efficiency.

Association of rivaroxaban plasma trough concentrations with clinical characteristics and outcomes

Background

Rivaroxaban use has increased significantly among older adults; however, no definitive plasma concentration thresholds for bleeding or thrombosis have been established. However, dose adjustments for this population remain controversial.

Methods

Between January 2022 and August 2023, we analyzed trough plasma samples from hospitalized patients treated with rivaroxaban for at least three consecutive days. Clinical data, including demographics, comorbidities, and adverse events, were extracted from electronic medical records. The plasma concentrations of rivaroxaban were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Statistical analyses were performed to identify factors influencing rivaroxaban exposure and clinical outcomes.

Results

Among 360 plasma samples analyzed (55% male; median age: 72 years), age (P = 0.042) and renal function (P = 0.002) were significant predictors of rivaroxaban concentration-to-dose ratio. Bleeding events were associated with higher trough concentrations (median: 81.85 ng/mL in the bleeding group vs. 26.80 ng/mL in others; P < 0.001) and were more common in patients with malignancies or prior bleeding history. Thrombotic events occurred predominantly in older patients with a history of stroke (P < 0.05). Patients who died were older and had higher CHA2DS2-VASc scores (P < 0.05), prolonged prothrombin times (P < 0.001), and multiple comorbidities.

Conclusion

Routine monitoring of rivaroxaban plasma concentrations may improve safety in older adults with multiple comorbidities or impaired hepatic, renal, or coagulation functions. Further research is required to establish specific therapeutic thresholds for bleeding and thrombosis.

Use of Direct Anticoagulants in Kidney Transplant Recipients: Review of the Current Evidence and Emerging Perspectives

Thromboembolic events and atrial fibrillation are common among kidney transplant recipients (KTRs), and these conditions typically require anticoagulation. Traditionally, vitamin K antagonists were used for management, but the use of direct oral anticoagulants (DOACs) has increased in KTRs. In the general population, DOACs are recommended over warfarin, but the applicability of these recommendations to KTRs is unclear because of risk-benefit concerns. There is some hesitancy to use DOACs in KTRs because of their dependence on renal clearance for elimination, potential drug-drug interactions, and limited data. To date, studies of DOACs in KTRs have demonstrated that they are efficient in thromboembolic events, major bleeding is rare, and drug-drug interactions appear rare. However, no guidance yet exists about the use of DOACs, reversal of DOAC action, and the pre- and post-kidney transplant management of DOACs in KTRs, and the evidence base is scarce. Thus, decisions on DOAC use in KTRs are based on expert opinion and the resources and experiences of individual transplant centers. This review summarizes 10 published studies on the use of DOACs in 741 KTRs, evaluating the side effects, efficacy, drug-drug interactions, and perioperative management compared with those of 1320 KTRs using vitamin K antagonists. Although current data are limited, DOACs appear to be relatively safe and effective in KTRs, with some studies suggesting lower bleeding rates and better kidney function than with vitamin K antagonists. However, more research with larger patient groups is needed to draw definitive conclusions.

Why patients fail to seek information on OTC product interactions with a direct-acting oral anticoagulant: perspectives on information-seeking

BACKGROUND

Many patients taking direct-acting oral anticoagulants (DOACs) also consume over-the-counter (OTC) products (dietary supplements and OTC medications), yet many lack knowledge of potential interactions that may increase or decrease DOAC efficacy and may not seek information about OTC products. The objective of this study was to describe patient attitudes and beliefs that inhibited information seeking about potential apixaban-OTC product interactions.

METHODS

Participants included English-, Spanish-, Mandarin-, and Cantonese-speaking adults from two large academic medical centers who reported taking apixaban (a frequently prescribed DOAC) in the past month. Thematic analysis was performed on semi-structured interviews.

RESULTS

Sixty patients aged 24-93 years (mean = 65.3; SD = 15.6) were interviewed; 55% were women. Participants took a total of 236 OTC products. Those with potential interactions with apixaban warranting consideration for therapy modification included: ibuprofen (n = 14; 5.9%), aspirin (n = 8; 3.4%), and naproxen (n = 3; 1.3%). Interviews revealed 5 major themes related to a lack of information-seeking about OTC products: (1) patients lack awareness of the potential for interactions; (2) patients believe that OTC products are safe and/or regulated (largely because they were familiar with the products, had previously taken them, or assumed that dietary supplements were regulated by the Food and Drug Administration); (3) patients believe that providers are responsible for alerting patients about potential interactions (as patients assumed that providers were aware of their OTC product use); (4) patients had prior knowledge of and/or used OTC products infrequently; and (5) obtaining information can be inconvenient. Inquiries regarding preferred information sources revealed 59 (98.3%) patients most frequently sought or would seek information from physicians and 34 (56.7%) from the internet.

CONCLUSIONS

Patients taking apixaban raised reasons for not seeking information about potential OTC product interactions that included poor awareness, perceptions regarding the safety of OTC products, and beliefs in provider responsibility for informing them about interactions. Greater patient education is needed regarding the potential for OTC product-DOAC interactions and the regulation of OTC products, particularly dietary supplements.

Modulation of Multispecific Transporters by Uncaria tomentosa Extract and Its Major Phytoconstituents

Background/Objectives: One of the major risks associated with the concomitant use of herbal products and therapeutic drugs is herb-drug interactions (HDIs). The most common mechanism leading to HDIs is the inhibition and/or induction of transport proteins and drug-metabolizing enzymes by herbal ingredients, causing changes in the pharmacokinetic disposition of the victim drug. The present study aimed to determine the potential interactions of Uncaria tomentosa (UT) (cat's claw), a popular herb due to its supposed health benefits. Methods: The effect of UT extract and its major oxindole alkaloids was investigated on multispecific solute carrier (SLC) and ATP-binding cassette (ABC) drug transporters, using SLC transporter-overexpressing cell lines and vesicles prepared from ABC transporter-overexpressing cells. Results: UT extract significantly inhibited all ABC transporters and the majority of the SLC transporters tested. Of the investigated oxindole alkaloids, isopteropodine significantly inhibited OATP, OCT1 and OCT2, OAT3, ENT4, MDR1, and BCRP transporters. OCTs, OCTN1-, ENT1-, and MDR1-mediated substrate accumulation was below 50% in the presence of mitraphylline. Conclusions: Based on the calculated intestinal concentration of UT extract, interactions with intestinal transporters, especially OATP2B1, ENTs, MRP1, MRP2, MDR1, and BCRP could be relevant in vivo. Our data can help to predict the clinical consequences of UT co-administration with drugs, such as increased toxicity or altered efficacy. In conclusion, the use of these in vitro models is applicable for the analysis of transporter-mediated HDIs similar to drug-drug interaction (DDI) prediction.

Equol Nonproducing Status as an Independent Risk Factor for Acute Cardioembolic Stroke and Poor Functional Outcome

Background/Objectives: Equol has protective effects against coronary artery disease and dementia by strongly binding to estrogen receptor beta, whereas the intake of soy isoflavone alone does not always confer such protective effects. Equol production is completely dependent on the existence of equol-producing gut microbiota. The effects of equol-producing status on the cerebrovascular diseases remain unclear. The current study was aimed to investigate the association of equol-producing status with the development of stroke and its neurological prognosis. Methods: Frequencies of equol producers were compared between healthy subjects (HS) registered in the Suita Study and patients with acute stroke admitted to our stroke center from September 2019 to October 2021 in a retrospective cohort study. Results: The proportion of HSs and patients with ischemic stroke who were equol producers did not significantly differ (50/103 [48.5%] vs. 60/140 [42.9%], p = 0.38). However, cardioembolic stroke was significantly associated with low a prevalence of equol producers (adjusted odds ratio [aOR] 0.46, 95% confidence interval [CI] 0.21-0.99, p = 0.05). A higher left atrial volume index was observed in equol nonproducers (46.3 ± 23.8 vs. 36.0 ± 11.6 mL/m2, p = 0.06). The equol nonproducers had a significantly higher prevalence of atrial fibrillation than the equol producers (27.5% vs. 13.3%, p = 0.04). Furthermore, the equol producers exhibited a significantly favorable functional outcome upon discharge (aOR 2.84, 95% CI 1.20-6.75, p = 0.02). Conclusions: Equol is a promising candidate for interventions aiming to reduce the risk of CES and atrial dysfunction, such as atrial fibrillation and improve neurological prognosis after ischemic stroke.

Pharmacokinetic and Pharmacodynamic Interactions between Food or Herbal Products and Oral Anticoagulants: Evidence Review, Practical Recommendations, and Knowledge Gaps

Interactions between food and oral anticoagulants (OACs), particularly vitamin K antagonists such as warfarin, are widely recognized and may also be clinically relevant for direct OACs. Pharmacokinetic and pharmacodynamic interactions with food or herbs can lead to anticoagulation potentiation, increased risk of bleeding, or reduced drug efficacy, all compromising patient safety. We conducted a systematic search for randomized controlled trials (RCTs) on PubMed for assessments of interactions between OACs and various ingestants. Since the RCT evidence was slim, we also reviewed prospective longitudinal studies, case series, and case reports to identify possible associations between foods and anticoagulation therapy. We referred to basic or translational studies that shared putative explanations for such interactions, but we failed to identify high-quality evidence in most cases. The limited evidence, small sample size of the studies, conflicting results, and possible heterogeneity in the contents of herbal products prevent a conclusive assessment of these interactions. Existing evidence suggests that (1) cranberry juice consumption (up to 240 mL/d and probably even more) with warfarin is safe; (2) use of green leafy vegetables with a high daily content (more than 250 µg) of vitamin K should be cautioned for patients receiving warfarin, because it may decrease warfarin efficacy. It is also advisable for patients to maintain highly constant intake of green leafy vegetables to ensure stable warfarin effectiveness; (3) ginger, even in small quantities (excluding commercial ginger-flavored beverages, which contain only negligible amounts of ginger), and mango (more than one fruit) can both potentiate warfarin effects; (4) patients taking OACs should avoid St. John's wort due to diminished anticoagulant effect; and (5) consumption of less than 240 mL of grapefruit juice daily is unlikely to interact with OACs. Future longitudinal observational cohort studies and RCTs with larger sample sizes are needed to study specific interactions between food or herbal products and OACs.

Application of a Novel UPLC-MS/MS Method for Analysis of Rivaroxaban Concentrations in Dried Blood Spot and Plasma Samples Collected from Patients with Venous Thrombosis

Despite a higher safety profile compared to vitamin K antagonists, rivaroxaban therapy is still connected with multiple adverse effects, such as a high risk of bleeding. Thus, therapeutic drug monitoring (TDM) of rivaroxaban concentrations is suggested. An alternative to plasma samples can be dried blood spots (DBS), which minimize the cost of sample storage and transport. In this study, we developed a UPLC-MS/MS method for the analysis of rivaroxaban in DBS and plasma samples. Chromatographic separation was achieved on a Zorbax Eclipse Plus C18 column (2.1 × 100 mm; 3.5 µm, Agilent Technologies Inc., Santa Clara, CA, USA) with a mobile phase consisting of water and acetonitrile, both containing 0.1% formic acid. The analytes were detected using a positive ionization mode by multiple reaction monitoring. We validated the method according to ICH guidelines. The precision and accuracy were satisfactory. Extraction recovery was approximately 57% and 66% for DBS and plasma samples, respectively. A high correlation between rivaroxaban concentrations in plasma and DBS samples collected from patients was confirmed with Deming regression. The suitability of both sampling techniques for the rivaroxaban TDM was also verified by Bland-Altman plots based on DBS-predicted and observed plasma concentrations. In addition, we found a significant relationship between rivaroxaban concentrations and coagulation parameters, including prothrombin time (PT) and international normalized ratio (INR).

Latest advances in the reversal strategies for direct oral anticoagulants

BACKGROUND

Since the late 2000s, Europe has granted approval for various thrombotic risk-related uses of direct oral anticoagulants (DOACs). Unlike traditional anticoagulants, DOACs do not necessitate routine coagulation monitoring. Nevertheless, clinical practice often encounters bleeding events associated with these medications, making the need for effective reversal strategies evident.

OBJECTIVES

The study aims to take stock of current reversal strategies for DOACs, with a particular emphasis on the latest compounds that have been developed or are currently under development.

METHODS

For obtaining information regarding the ongoing reversal strategies and the compounds under development, we referred to ClinicalTrials website, PubMed, and Google Scholar.

RESULTS

In 2024, two specific antidotes to DOACs have already received approval when reversal of anticoagulation is needed owing to life-threatening or uncontrolled bleeding: idarucizumab that reverses the effects of dabigatran, and andexanet alfa, designed to counteract activated factor X inhibitors such as apixaban and rivaroxaban. Furthermore, ciraparantag, a potential universal reversal agent, is currently in advanced stages of clinical development. Concerns remain regarding the safety of specific reversal agents, especially concerning the risk of thrombosis. Additionally, the cost of these antidotes remains high. Consequently, nonspecific strategies to counteract anticoagulant medications, including activated charcoal, hemodialysis, and concentrates of coagulation factors, still have utility.

CONCLUSION

With the validation of specific and nonspecific antidotes, DOACs could supplant traditional oral anticoagulants. This progress represents a significant advancement in anticoagulation therapy. However, ongoing research is crucial to address remaining safety concerns of the specific reversion agents of DOACs in clinical practice.

An Update on Betrixaban, The Challenging Anticoagulant Agent for Extended Venous Thromboembolism Prophylaxis

ABSTRACT

Venous thromboembolism (VTE) is a prevalent yet preventable cause of death, particularly among hospitalized patients. Studies have shown that the risk of VTE remains high for up to 6 months after discharge, highlighting the need for extended thromboprophylaxis as a viable treatment approach. Despite the availability of several anticoagulant drugs such as vitamin K antagonists, heparinoids, rivaroxaban, apixaban, edoxaban, and dabigatran, none of them has received approval from the US Food and Drug Administration for long-term thromboprophylaxis. However, an emerging factor Xa inhibitor called betrixaban has shown promising results in Phase II and phase III trials, positioning itself as the first and only US Food and Drug Administration-approved anticoagulant for extended thromboprophylaxis in hospitalized patients after discharge. Betrixaban offers distinct pharmacological characteristics, including a long half-life, low renal excretion, and unique hepatic metabolism, making it an attractive option for various theoretical uses. Numerous articles have been published discussing the safety and efficacy of betrixaban, all of which have emphasized its usefulness and practicality. However, there has been limited discussion regarding its weaknesses and areas of ambiguity. Therefore, this article aimed to explore the challenges faced during the approval process of betrixaban and provide a comprehensive review of the literature on its advantages and disadvantages as a long-term prophylaxis approach for VTE. Furthermore, we aim to identify the ambiguous points that require further investigation in future studies.

Knowledge, Attitudes, and Awareness of Food and Drug Interactions (FDI) Among Nurses on General Medical Wards: A Cross-Sectional Study

Background

Food and nutritional supplements can interact with medication and cause drug interaction. Registered nurses play an essential role in patients' safety related to drug interaction.

Objective

Explore nurses' knowledge, attitudes, and awareness regarding food-drug interactions (FDIs).

Method

A cross-sectional survey was conducted among nurses working in the general medical wards at Hamad General Hospital (HGH) in Qatar. The survey questionnaire comprised 50 multiple-choice questions, encompassing three key sections: (a) demographic details, (b) assessment of FDIs knowledge, and (c) exploration of beliefs, attitudes, and practices concerning FDIs.

Results

A total of 227 surveys were collected. Nurses' average score for FDI knowledge across all responses was 20 out of 34 (IQR 16-25). Notably, there were no statistically significant differences in average scores based on respondents' demographic subgroups. While nurses displayed a high level of knowledge (over 90%) regarding the timing of food and drug intake for proton pump inhibitors, nonsteroidal anti-inflammatory drugs, and thyroid hormones, they exhibited limited awareness of the possible FDIs related to carvedilol and furosemide. Approximately half of the participating nurses (56.4%) rated their FDI knowledge as satisfactory. However, only 42.3% claimed to be always educating patients about FDIs in their daily practice. Two-thirds (67.4%) of respondents believed educating patients about FDIs should primarily fall under the responsibility of pharmacists.

Conclusion

This study highlights the nurses' knowledge, attitudes, and beliefs of FDIs. Prompt intervention is required to enhance the nurse's awareness and knowledge in this domain which may impact patient care and drug safety.

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.

Unveiling the Multifaceted Problems Associated with Dysrhythmia

Dysrhythmia is a term referring to the occurrence of spontaneous and repetitive changes in potentials with parameters deviating from those considered normal. The term refers to heart anomalies but has a broader meaning. Dysrhythmias may concern the heart, neurological system, digestive system, and sensory organs. Ion currents conducted through ion channels are a universal phenomenon. The occurrence of channel abnormalities will therefore result in disorders with clinical manifestations depending on the affected tissue, but phenomena from other tissues and organs may also manifest themselves. A similar problem concerns the implementation of pharmacotherapy, the mechanism of which is related to the impact on various ion currents. Treatment in this case may cause unfavorable effects on other tissues and organs. Drugs acting through the modulation of ion currents are characterized by relatively low tissue specificity. To assess a therapy's efficacy and safety, the risk of occurrences in other tissues with similar mechanisms of action must be considered. In the present review, the focus is shifted prominently onto a comparison of abnormal electrical activity within different tissues and organs. This review includes an overview of the types of dysrhythmias and the basic techniques of clinical examination of electrophysiological disorders. It also presents a concise overview of the available pharmacotherapy in particular diseases. In addition, the authors review the relevant ion channels and their research technique based on patch clumping.

Implementation of recommendations on the check of risk factors for cardiovascular diseases in patients undergoing coronary re-interventions

METHOD

The study involved 905 patients after coronary interventions, qualified for invasive diagnosis due to symptomatic coronary disease.

AIM

The aim of this study was to check the implementation of recommendations on the control of risk factors for cardiovascular diseases in patients undergoing re-interventions.

RESULTS

Compared to elderly persons, younger people more often increased their physical activity (62 vs. 65 years, p = 0.009), stopped smoking (61 vs. 65 years, p < 0.001) and reduced alcohol consumption (62 vs. 65 years, p = 0.001). People with secondary and higher education increased their physical activity more often than those with primary education (51%, 31% vs. 23%, p = 0.006). Men more often than women decided to limit their alcohol consumption (48% vs. 37%, p = 0.007). Patients with a history of acute coronary syndrome were more likely to quit smoking and reduce their alcohol consumption than those without such a history (47% vs. 37%, p = 0.003 and 42% vs. 34%, p = 0.020, respectively). Only 2% of the subjects achieved the recommended LDL cholesterol values. Forty-eight percent were qualified for reinvasive procedures on the coronary arteries. Less than half of the patients undertook health-promoting behaviors that required modification of existing habits.

CONCLUSION

Age, gender, and education level influence pro-health behaviors. The majority of patients do not achieve the levels of LDL cholesterol and triglycerides consistent with the ESC guidelines in the secondary prevention of coronary disease. Inadequate check of risk factors may result in faster disease progression and coronary re-interventions.

The Role of Injectables in the Treatment and Prevention of Cancer-Associated Thrombosis

Cancer-associated thrombosis (CAT) is a leading cause of death among patients with cancer. CAT can manifest itself as venous thromboembolism (VTE), in the form of deep vein thrombosis or pulmonary embolism, or arterial thromboembolism. The pathophysiology of CAT is complex and depends on cancer-, patient-, treatment- and biomarkers-related factors. Treatment of VTE in patients with cancer is complex and includes three major classes of anticoagulant agents: heparin and its derivatives, e.g., low molecular weight heparins, direct oral anticoagulants (DOACs), and vitamin K inhibitors. Given the tremendous heterogeneity of clinical situations in patients with cancer and the challenges of CAT, there is no single universal treatment option for patients suffering from or at risk of CAT. Initial studies suggested that patients seemed to prefer an anticoagulant that would not interfere with their cancer treatment, suggesting the primacy of cancer over VTE, and favoring efficacy and safety over convenience of route of administration. Recent studies show that when the efficacy and safety aspects are similar, patients prefer the oral route of administration. Despite this, injectables are a valid option for many patients with cancer.

Therapeutic Drug Monitoring of Direct Oral Anticoagulants in Patients with Extremely Low and High Body Weight-Pilot Study

Phase III clinical trials for individual direct oral anticoagulants (DOACs) contained a limited representation of subjects with abnormal body weight, which were mostly limited to a BMI > 40 kg/m2, or body weight > 120 kg for obese subjects, and <50 kg for underweight subjects. Although low or high body weight is not a contraindication to DOACs therapy, it can significantly affect the safety and effectiveness of treatment. Due to the limited amount of clinical data on the use of DOACs in extremely abnormal weight ranges, optimal pharmacotherapy in this group of patients is a matter of controversy. The objective of this study was to evaluate the pharmacokinetics of DOAC properties in patients with abnormal body weight beyond the established cut-off points in the phase III studies for rivaroxaban, apixaban, and dabigatran. In total, 38 patients took DOACs for at least 12 months for non-valvular atrial fibrillation in 2019-2021. Blood samples were collected before the planned intake of the drug and 4 h after its administration. The determined concentrations of DOACs were statistically analyzed in relation to body weight, age, and eGFR (estimated Glomerular Filtration Rate). Among subjects taking apixaban, rivaroxaban, and dabigatran, the smallest representation of patients who achieved therapeutic concentrations were those treated with dabigatran. The population of people with abnormal body weight is a potential risk group of patients, in which some of them do not reach the therapeutic range of DOACs.

Antioxidant Properties of Oral Antithrombotic Therapies in Atherosclerotic Disease and Atrial Fibrillation

The thrombosis-related diseases are one of the leading causes of illness and death in the general population, and despite significant improvements in long-term survival due to remarkable advances in pharmacologic therapy, they continue to pose a tremendous burden on healthcare systems. The oxidative stress plays a role of pivotal importance in thrombosis pathophysiology. The anticoagulant and antiplatelet drugs commonly used in the management of thrombosis-related diseases show several pleiotropic effects, beyond the antithrombotic effects. The present review aims to describe the current evidence about the antioxidant effects of the oral antithrombotic therapies in patients with atherosclerotic disease and atrial fibrillation.

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.

Utility of Therapeutic Drug Monitoring in Identifying Clinically Significant Interactions Between St. John's Wort and Prescription Drugs

BACKGROUND

The general population widely uses herbal medicines, as they are regarded as effective and safe. St. John's wort, which is an effective herbal antidepressant, exhibits both pharmacokinetic and pharmacodynamic interactions with several drugs. The aim of this review was to highlight the clinically significant interactions of St. John's wort with drugs that require to be monitored to assess their therapeutic effect.

METHODS

Published literature was searched using electronic databases, such as MEDLINE, PubMed, and Elsevier ScienceDirect using terms such as "herbal medicine," "herbal toxicity," "legislation herbal medicine," "drug-herb interactions," "St. John's wort," and "St. John's wort-drug interactions." Searches were limited to the English language, and there was no restriction on the date of publication.

RESULTS

St. John's wort exhibits a number of pharmacokinetic and pharmacodynamic interactions with drugs. The most dangerous interactions occurred when used concurrently with the immunosuppressants, cyclosporine, and tacrolimus (treatment failure or organ rejection) or warfarin (treatment failure resulting in thromboembolic events) or antiretroviral agents (treatment failure and the emergence of new viral variants that are resistant to conventional drugs).

CONCLUSIONS

Patients should consult their health care providers before consuming herbal supplements, especially St. John's wort, to avoid potentially dangerous drug-herb interactions.

Soluble Guanylyl Cyclase Activators-Promising Therapeutic Option in the Pharmacotherapy of Heart Failure and Pulmonary Hypertension

Endogenous nitric oxide (NO)-dependent vascular relaxation plays a leading role in the homeostasis of the cardiovascular, pulmonary, and vascular systems and organs, such as the kidneys, brain, and liver. The mechanism of the intracellular action of NO in blood vessels involves the stimulation of the activity of the soluble cytosolic form of guanylyl cyclase (soluble guanylyl cyclase, sGC), increasing the level of cyclic 3'-5'-guanosine monophosphate (cGMP) in smooth muscle and subsequent vasodilation. In recent years, a new group of drugs, soluble guanylyl cyclase stimulators, has found its way into clinical practice. Based on the CHEST-1 and PATENT-1 trials, riociguat was introduced into clinical practice for treating chronic thromboembolic pulmonary hypertension (CTEPH). In January 2021, the FDA approved the use of another drug, vericiguat, for the treatment of heart failure.

Beta-blockers in cardiac arrhythmias-Clinical pharmacologist's point of view

β-blockers is a vast group of antiarrhythmic drugs which differ in their pharmacokinetic and chemical properties. Some of them block β-adrenergic receptors selectively while the others work non-selectively. Consequently, they reduce the influence of the sympathetic nervous system on the heart, acting negatively inotropic, chronotropic, bathmotropic and dromotropic. Although they have been present in medicine since the beginning of the 1960s, they still play a crucial role in the treatment of cardiac arrhythmias. They are also first-line group of drugs used to control the ventricular rate in patients with the most common arrhythmia-atrial fibrillation. Previous reports indicate that infection with SARS-CoV-2 virus may constitute an additional risk factor for arrhythmia. Due to the aging of the population in developed countries and the increase in the number of patients with cardiac burden, the number of people suffering from cardiac arrhythmias will increase in the upcoming years. As a result the role of above-mentioned beta-blockers will remain significant. Particularly noteworthy is propranolol-the oldest beta adrenergic antagonist, which in recent years has found additional applications due to its unique properties. In this article, we reviewed the accessible literature and summarized the current guidelines on the use of beta-blockers in the treatment of cardiac arrhythmias.

Population Pharmacokinetics and Hemorrhagic Risk Analysis of Rivaroxaban in Elderly Chinese Patients With Nonvalvular Atrial Fibrillation

Rivaroxaban is a popular direct factor Xa inhibitor used for anticoagulation therapy in patients with nonvalvular atrial fibrillation (NVAF). The aim of this study was to establish a population pharmacokinetic (PPK) model for rivaroxaban in elderly Chinese patients with nonvalvular atrial fibrillation, evaluate precision dosing regimens, and analyze hemorrhagic risk after rivaroxaban treatment. A 1-compartment population PK model with estimated glomerular filtration rate (eGFR), total bilirubin (TBIL), and ABCB1 rs1045642 as major covariates for apparent clearance was developed using the nonlinear mixed-effects model (NONMEM). A Monte Carlo simulation was performed to evaluate various dosing schemes and different levels of covariates for the target range of therapeutic drug-monitoring concentrations (C_max,ss and C_min,ss ). The exposure to rivaroxaban was simulated and assessed through hemorrhagic risk evaluation. The results showed that the average probability of target attainment (PTA) for optimal dosing regimens with different covariate levels for the targeted C_max,ss and C_min,ss were 29.35% to 31.3% and 64.91% to 65.8%, respectively. A dosage of 10 mg of rivaroxaban in elderly Chinese patients with normal renal and liver function was appropriate. The area under the concentration-time curve estimated over 24 hours with precision dosing at steady state (AUC_24,ss ) was statistically significantly associated with an increased risk of bleeding events (OR 1.0006, 95%CI 1.0003 to 1.001, P < .0001), and the bleeding risk increased by 1.82-fold for every 1000 μg*h/L increase in AUC_24,ss . A lower dose is recommended for elderly patients with renal impairment to avoid overexposure and bleeding events. The PPK model could inform individualized dosing for elderly Chinese patients with nonvalvular atrial fibrillation receiving rivaroxaban anticoagulation therapy.

Direct oral anticoagulants (DOACs): From the laboratory point of view

Direct oral anticoagulants (DOACs) represent a new generation of drugs that have been increasingly used in the prevention and treatment of thromboembolic states. According to the mechanism of anticoagulant action, DOACs are divided into two groups: direct inhibitors of thrombin (dabigatran) and direct inhibitors of activated factor X (FXa) (rivaroxaban, apixaban, edoxaban, betrixaban). Compared to the vitamin K antagonists, DOACs are superior in terms of onset of action, pharmacokinetic and pharmacodynamics properties and fixed daily dose without the need for routine coagulation monitoring. Despite these advantages, there are clinical conditions in which laboratory measurement of DOACs should be performed. Although DOACs have an impact on screening haemostasis assays (prothrombin time, PT; activated partial thromboplastin time, aPTT; and thrombin time, TT), these tests are not appropriate for quantifying drug levels. Therefore, specific quantitative methods (LC-MS/MS as a gold standard method for all DOACs, coagulometric and chromogenic assays for dabigatran, and chromogenic anti-Xa assays with drug-specific calibrators for inhibitors of FXa) should only be used for determination of DOACs concentration. The aim of this review is to present all aspects of laboratory assessment of DOACs, including pre-analytical, analytical and post-analytical factors in the overall testing process with a special accent on the available specific quantitative methods for measurement of DOACs in circulation.

Alcohol and Cardiovascular Diseases—Do the Consumption Pattern and Dose Make the Difference?

Excessive consumption of alcohol is not only a social problem, but it also significantly increases the morbidity and mortality rates of many societies. A correlation has been demonstrated between alcohol consumption and increased mortality from cancer, accidents and injuries, liver cirrhosis and other causes. Alcohol abuse increases the incidence of hemorrhagic stroke and the risk of ischemic stroke, induces serious arrhythmias, adversely affects blood pressure and damages the heart muscle. The dose and way of drinking alcohol play a crucial role in assessing whether this drink allows people to maintain health or whether it is a great health and social threat. The beneficial effects of low and moderate doses of alcohol on the occurrence of cardiovascular diseases have been shown in many population studies and meta-analyses in which the effect of U-shaped or J-shaped curves relating alcohol intake to cardiovascular mortality was observed, especially in ischemic heart disease. However, due to the fact that alcohol consumption is associated with many health hazards, it is not recommended to consume it as a preventive action of cardiovascular diseases. Moreover, recent studies suggest that association of low-to-moderate alcohol consumption with the reduction in cardiovascular risk is a result of lifestyle changes and that any reduction in alcohol consumption is in fact beneficial in terms of general health.

Dilemmas in the Choice of Adequate Therapeutic Treatment in Patients with Acute Pulmonary Embolism—From Modern Recommendations to Clinical Application

Pulmonary thromboembolism is a very common cardiovascular disease, with a high mortality rate. Despite the clear guidelines, this disease still represents a great challenge both in diagnosis and treatment. The heterogeneous clinical picture, often without pathognomonic signs and symptoms, represents a huge differential diagnostic problem even for experienced doctors. The decisions surrounding this therapeutic regimen also represent a major dilemma in the group of patients who are hemodynamically stable at initial presentation and have signs of right ventricular (RV) dysfunction proven by echocardiography and positive biomarker values (pulmonary embolism of intermediate–high risk). Studies have shown conflicting results about the benefit of using fibrinolytic therapy in this group of patients until hemodynamic decompensation, due to the risk of major bleeding. The latest recommendations give preference to new oral anticoagulants (NOACs) compared to vitamin K antagonists (VKA), except for certain categories of patients (patients with antiphospholipid syndrome, mechanical valves, pregnancy). When using oral anticoagulant therapy, special attention should be paid to drug–drug interactions, which can lead to many complications, even to the death of the patient. Special population groups such as pregnant women, obese patients, patients with antiphospholipid syndrome and the incidence of cancer represent a great therapeutic challenge in the application of anticoagulant therapy. In these patients, not only must the effectiveness of the drugs be taken into account, but great attention must be paid to their safety and possible side effects, which is why a multidisciplinary approach is emphasized in order to provide the best therapeutic option.

Safety of Non-Vitamin K Antagonist Oral Anticoagulant Treatment in Patients with Chronic Kidney Disease and Kidney Transplant Recipients

The use of novel oral anticoagulants in patients with impaired renal function or undergoing immunosuppressive therapy is limited due to the risk of drug-to-drug interactions and anticoagulation-related adverse events. This article aims to assess the current data on the safety of direct-acting oral anticoagulant-based therapy in the population of kidney transplant recipients and patients with impaired renal function. The most important factors affecting the safety of treatment are the incidence of bleeding events, thromboembolic events, deaths and drug-to-drug interactions. The available data were compared to the findings on warfarin-based anticoagulation. Findings on the use of novel oral anticoagulants in kidney transplant recipients are limited yet promising in terms of safety and efficacy of use. However, current recommendations state that the co-administration of non-vitamin K antagonist oral anticoagulants with several immunosuppressive agents is contraindicated.

Association of Rivaroxaban vs Apixaban With Major Ischemic or Hemorrhagic Events in Patients With Atrial Fibrillation

IMPORTANCE

The comparative effectiveness of rivaroxaban and apixaban, the most frequently prescribed oral anticoagulants for ischemic stroke prevention in patients with atrial fibrillation, is uncertain.

OBJECTIVE

To compare major ischemic and hemorrhagic outcomes in patients with atrial fibrillation treated with rivaroxaban or apixaban.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study using computerized enrollment and claims files for US Medicare beneficiaries 65 years or older. Between January 1, 2013, and November 30, 2018, a total of 581 451 patients with atrial fibrillation began rivaroxaban or apixaban treatment and were followed up for 4 years, through November 30, 2018.

EXPOSURES

Rivaroxaban (n = 227 572) and apixaban (n = 353 879), either standard or reduced dose.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of major ischemic (stroke/systemic embolism) and hemorrhagic (intracerebral hemorrhage/other intracranial bleeding/fatal extracranial bleeding) events. Secondary outcomes were nonfatal extracranial bleeding and total mortality (fatal ischemic/hemorrhagic event or other death during follow-up). Rates, hazard ratios (HRs), and rate differences (RDs) were adjusted for baseline differences in comorbidity with inverse probability of treatment weighting.

RESULTS

Study patients (mean age, 77.0 years; 291 966 [50.2%] women; 134 393 [23.1%] receiving reduced dose) had 474 605 person-years of follow-up (median [IQR] of 174 [62-397] days). The adjusted primary outcome rate for rivaroxaban was 16.1 per 1000 person-years vs 13.4 per 1000 person-years for apixaban (RD, 2.7 [95% CI, 1.9-3.5]; HR, 1.18 [95% CI, 1.12-1.24]). The rivaroxaban group had increased risk for both major ischemic events (8.6 vs 7.6 per 1000 person-years; RD, 1.1 [95% CI, 0.5-1.7]; HR, 1.12 [95% CI, 1.04-1.20]) and hemorrhagic events (7.5 vs 5.9 per 1000 person-years; RD, 1.6 [95% CI, 1.1-2.1]; HR, 1.26 [95% CI, 1.16-1.36]), including fatal extracranial bleeding (1.4 vs 1.0 per 1000 person-years; RD, 0.4 [95% CI, 0.2-0.7]; HR, 1.41 [95% CI, 1.18-1.70]). Patients receiving rivaroxaban had increased risk of nonfatal extracranial bleeding (39.7 vs 18.5 per 1000 person-years; RD, 21.1 [95% CI, 20.0-22.3]; HR, 2.07 [95% CI, 1.99-2.15]), fatal ischemic/hemorrhagic events (4.5 vs 3.3 per 1000 person-years; RD, 1.2 [95% CI, 0.8-1.6]; HR, 1.34 [95% CI, 1.21-1.48]), and total mortality (44.2 vs 41.0 per 1000 person-years; RD, 3.1 [95% CI, 1.8-4.5]; HR, 1.06 [95% CI, 1.02-1.09]). The risk of the primary outcome was increased for rivaroxaban in both those receiving the reduced dose (27.4 vs 21.0 per 1000 person-years; RD, 6.4 [95% CI, 4.1-8.7]; HR, 1.28 [95% CI, 1.16-1.40]) and the standard dose (13.2 vs 11.4 per 1000 person-years; RD, 1.8 [95% CI, 1.0-2.6]; HR, 1.13 [95% CI, 1.06-1.21]) groups.

CONCLUSIONS AND RELEVANCE

Among Medicare beneficiaries 65 years or older with atrial fibrillation, treatment with rivaroxaban compared with apixaban was associated with a significantly increased risk of major ischemic or hemorrhagic events.