Review on mechanisms and interactions in concomitant use of herbs and warfarin therapy

Warfarin-A natural anticoagulant: A review of research trends for precision medication

BACKGROUND

Warfarin is a widely prescribed anticoagulant in the clinic. It has a more considerable individual variability, and many factors affect its variability. Mathematical models can quantify the quantitative impact of these factors on individual variability.

PURPOSE

The aim is to comprehensively analyze the advanced warfarin dosing algorithm based on pharmacometrics and machine learning models of personalized warfarin dosage.

METHODS

A bibliometric analysis of the literature retrieved from PubMed and Scopus was performed using VOSviewer. The relevant literature that reported the precise dosage of warfarin calculation was retrieved from the database. The multiple linear regression (MLR) algorithm was excluded because a recent systematic review that mainly reviewed this algorithm has been reported. The following terms of quantitative systems pharmacology, mechanistic model, physiologically based pharmacokinetic model, artificial intelligence, machine learning, pharmacokinetic, pharmacodynamic, pharmacokinetics, pharmacodynamics, and warfarin were added as MeSH Terms or appearing in Title/Abstract into query box of PubMed, then humans and English as filter were added to retrieve the literature.

RESULTS

Bibliometric analysis revealed important co-occuring MeShH and index keywords. Further, the United States, China, and the United Kingdom were among the top countries contributing in this domain. Some studies have established personalized warfarin dosage models using pharmacometrics and machine learning-based algorithms. There were 54 related studies, including 14 pharmacometric models, 31 artificial intelligence models, and 9 model evaluations. Each model has its advantages and disadvantages. The pharmacometric model contains biological or pharmacological mechanisms in structure. The process of pharmacometric model development is very time- and labor-intensive. Machine learning is a purely data-driven approach; its parameters are more mathematical and have less biological interpretation. However, it is faster, more efficient, and less time-consuming. Most published models of machine learning algorithms were established based on cross-sectional data sourced from the database.

CONCLUSION

Future research on personalized warfarin medication should focus on combining the advantages of machine learning and pharmacometrics algorithms to establish a more robust warfarin dosage algorithm. Randomized controlled trials should be performed to evaluate the established algorithm of warfarin dosage. Moreover, a more user-friendly and accessible warfarin precision medicine platform should be developed.

Knowledge levels of doctors and nurses working in surgical clinics about nutrients and food supplements, a multicentre descriptive study

PURPOSE

The use of nutrients and food supplements is increasing worldwide. Nutrients and food supplements frequently used in the surgical period may cause complications and side effects. This study was conducted to determine the level of knowledge about sixty-one nutrients and food supplements among doctors and nurses working in surgical clinics.

DESIGN

A multicentre descriptive, quantitative, cross-sectional study.

METHODS

The study was conducted between 15 February and 31 May 2022 with a total of 410 participants, including 143 doctors and 267 nurses, working in the surgical clinics of 8 hospitals, including public, university and private hospitals, within the borders of one province in Turkey. Data were collected face-to-face using a questionnaire developed by the researchers, which included descriptive characteristics of the doctors and nurses and questions about sixty-one nutrients and food supplements.

RESULTS

The median overall success score of the doctors and nurses participating in the study regarding the use of nutrients and food supplements was 3.20 out of 100 points, the median success score of complications and side effects of nutrients and food supplements in the surgical period was 7.06 out of 33 points, the median success score for discontinuation of nutrients and food supplements prior to surgery was 0.21 out of 16 points, and the median success score for drug interactions of nutrients and food supplements was 1.70 out of 51 points. In addition, it was found that the overall success scores of doctors and nurses regarding nutrients and food supplements increased statistically significantly with increasing age and working years. The total success score of doctors and nurses who received training in nutrients and food supplements was statistically significantly higher than that of doctors and nurses who did not receive training.

CONCLUSION

In conclusion, it was found that the level of knowledge of nutrients and food supplements among doctors and nurses working in surgical clinics was less than half or even close to zero. Therefore, it is recommended that training on nutrients and food supplements should be included in the undergraduate and postgraduate education of doctors and nurses in order to prevent complications, side effects, drug interactions and patient safety related to the use of nutrients and food supplements in the surgical period.

Effects of sodium ferulate for injection on anticoagulation of warfarin in rats in vivo

BACKGROUND

Herb-drug interactions may result in increased adverse drug reactions or diminished drug efficacy, especially for drugs with a narrow therapeutic index such as warfarin. The current study investigates the effects of sodium ferulate for injection (SFI) on anticoagulation of warfarin from aspects of pharmacodynamics and pharmacokinetics in rats and predicts the risk of the combination use.

METHODS

Rats were randomly divided into different groups and administered single- or multiple-dose of warfarin (0.2 mg/kg) with or without SFI of low dose (8.93 mg/kg) or high dose (26.79 mg/kg). Prothrombin time (PT) and activated partial thromboplastin time (APTT) were detected by a blood coagulation analyzer, and international normalized ratio (INR) values were calculated. UPLC-MS/MS was conducted to measure concentrations of warfarin enantiomers and pharmacokinetic parameters were calculated by DAS2.0 software.

RESULTS

The single-dose study demonstrated that SFI alone had no effect on coagulation indices, but significantly decreased PT and INR values of warfarin when the two drugs were co-administered (P < 0.05 or P < 0.01), while APTT values unaffected (P > 0.05). Cmax and AUC of R/S-warfarin decreased but CL increased significantly in presence of SFI (P < 0.01). The multiple-dose study showed that PT, APTT, INR, and concentrations of R/S-warfarin decreased significantly when SFI was co-administered with warfarin (P < 0.01). Warfarin plasma protein binding rate was not significantly changed by SFI (P > 0.05).

CONCLUSIONS

The present study implied that SFI could accelerate warfarin metabolism and weaken its anticoagulation intensity in rats.

Anticoagulation decision-making before non-cardiac surgery in patients with mechanical heart valve: A retrospective study

Objective

To clarify the timing of warfarin discontinuation at different ranges of INR. Improve anticoagulation management in non-cardiac surgical patients with MHV.

Design

This is a single-center retrospective observational study.

Setting

and participants This study used data from the Hospital Information System, and the Surgery and Anesthesia Information System of the Second Affiliated Hospital of Army Military Medical University. Participants included 121 adult patients with MHV who underwent non-cardiac surgery from 2012 to 2021.

Results

Overall, 121 patients with MHV (15 aortic valve only, 56 mitral valve only, and 50 with multiple valves) underwent non-cardiac surgery. When the duration of warfarin discontinuation was ≤ 3 days, 3-5 days, and≥5 days, the INR was 1.45, 1.15, and 1.09, respectively. Bleeding between INR ≤1.2 and INR >1.2 groups was not statistically significant using Student's t-test (95% CI -0.57, 0.14 P = 0.24). Multivariate regression analysis revealed that Intraoperative bleeding volume correlated with preoperative albumin levels (OR = 0.68，95% CI 0.49, 0.89).

Conclusions

When need preoperative INR is less than 1.5 in patients with MHV undergoing non-cardiac surgery, preoperative warfarin discontinuation for 3 days is sufficient. If INR less than 1.2, preoperative warfarin discontinuation for 3-5 days is appropriate. And in patients with MHV underwent abdominal surgery, intraoperative bleeding is not significant reduced by lower INR after preoperative warfarin discontinuation. Furthermore, the effect of albumin levels on coagulation function cannot be ignored in patients with MHV.

Strengths and limitations

This study was derived from real-world clinical data. It's a retrospectively study to describe the INR changed according to the duration of warfarin discontinuation in patients with MHV and compared intraoperation of bleeding volume between INR>1.2 and INR ≤ 1.2after warfarin discontinuation. To clarify the timing of warfarin discontinuation at different ranges of INR. Improve anticoagulation management in non-cardiac surgical patients with MHV, while providing clinicians with a reference for preoperative warfarin adjustment. This study does have a few limitations. The number of cases is small because patients undergoing repeat noncardiac surgery after heart valve surgery are a special case population. And the patients were not followed up after non-cardiac surgery. The impact of changes in INR on postoperative complications could not be assessed in patients with MHV.

Cytochrome P450-mediated herb-drug interaction (HDI) of Polygonum multiflorum Thunb. based on pharmacokinetic studies and in vitro inhibition assays

BACKGROUND

Polygonum multiflorum Thunb. (PM) is well known both in China and other countries of the world for its tonic properties, however, it has lost its former glory due to liver toxicity incidents in recent years.

PURPOSE

The purpose of this study is to determine whether the occurrence of herb-drug interaction (HDI) caused by PM is associated with cytochrome P450 (CYP450) based on pharmacokinetic studies and in vitro inhibition assays. The objective was to provide a reference for the rational and safe use of drugs in clinical practice.

METHODS

In this study, raw PM (R), together with its two processed products which included PM by Chinese Pharmacopoeia (M) and PM by "nine cycles of steaming and sunning (NCSS)" ("9"), were prepared as the main research objects. A method based on fluorescence technology was used to evaluate the inhibition levels of raw and processed PMs, as well as corresponding characteristic compounds on seven recombinant human cytochrome P450s (rhCYP450s). The pharmacokinetics of sulindac (a representative of commonly used nonsteroidal anti-inflammatory drugs) and psoralen (a major compound of Psoralea in combination with PM) in rat plasma were studied when combined with raw and different processed products of PM.

RESULTS

The inhibitory level order of the three extracts on major different subtypes of CYP450 (CYP1A2, CYP2B6, CYP2C8, CYP2C19, CYP2D6, and CYP3A4) was: R > M > "9". However, the inhibition level of R and "9" is higher than that of M on CYP2C9. Further studies showed that trans-THSG and emodin could selectively inhibit CYP3A4 and CYP1A2, respectively. Epicatechin gallate mainly inhibited CYP3A4 and CYP1A2, followed by CYP2C8 and CYP2C9. Genistein mainly inhibited CYP3A4, followed by CYP2C9 and CYP2C8. CYP3A4 and CYP2C9 were also inhibited by daidzein. The inhibitory effects of all the PM extracts were associated with their characteristic compounds. The results of HDI showed that R increased sulindac exposure to rat blood, and R and M increased psoralen exposure to rat blood, which were consistent with corresponding metabolic enzymes. Overall, the in vitro and in vivo results indicated that PM, especially R, would be at high risk to cause toxicity and drug interactions via CYP450 inhibition.

CONCLUSION

This study not only elucidates the scientific connotation of "efficiency enhancement and toxicity reduction" of PM by NCSS from the perspective of metabolic inhibition but also contributes to HDI prediction and appropriate clinical medication of PM.

Investigation of the separate and simultaneous bindings of warfarin and fenofibrate to bovine serum albumin

Lipid-lowering drugs are often taken with anticoagulant drugs in hyperlipidemia patients. Fenofibrate (FNBT) and warfarin (WAR) are common clinical lipid-lowering drugs and anticoagulant drugs, respectively. A study of binding affinity, binding force, binding distance, and binding sites was performed to determine the interaction mechanism between drugs and carrier proteins (bovine serum albumin, BSA), as well as their effects on BSA conformation. Both FNBT and WAR can form complexes with BSA by van der Waals force and hydrogen bonds. WAR had a stronger fluorescence quenching effect on BSA, a stronger binding affinity, and greater effects on BSA conformation than FNBT. According to fluorescence spectroscopy and cyclic voltammetry, co-administration of drugs decreased one drug's binding constant to BSA and increased its binding distance. This suggested that each drug's binding to BSA was disturbed by each other, as well as each drug's binding ability to BSA was altered by the other. It was demonstrated that co-administration of drugs had greater effects on the secondary structure of BSA and microenvironment polarity surrounding amino acid residues, using multiple spectroscopy techniques, such as ultraviolet spectroscopy, Fourier transform infrared spectroscopy, and synchronous fluorescence spectroscopy.

Antithrombotic potential of Lippia alba: A mechanistic approach

ETHNOPHARMACOLOGICAL RELEVANCE

Lippia alba (Mill.) N.E.Br. ex Britton & P. Wilson is traditionally used in Brazil as an adjunct in the relief of mild anxiety, as an antispasmodic, and as an antidyspeptic. This medicinal species was included in the Phytotherapeutic Form of the Brazilian Pharmacopeia 2nd edition (2021) and has already been described as the most used medicinal plant in a study with patients from an Anticoagulation Clinic in Brazil. Meanwhile, no studies were found that support the safety of the use of L. alba in patients using anticoagulants, a drug with several safety limitations.

AIM OF THE STUDY

Provide scientific evidence to ensure the safety of the concomitant use of L. alba and warfarin and support the management of these patients by evaluating its in vitro anticoagulant effect and chemical composition. And, as a timely complementation, evaluate the potential of this medicinal species in the development of new antithrombotics.

METHODS

The chemical profile of L. alba derivatives was analyzed by chromatographic methods such as Ultra-Performance Liquid Chromatography (UPLC) coupled with electrospray ionization mass spectrometry (ESI-MS), qualitative UPLC using Diode-Array Detection, and Thin Layer Chromatography. The anticoagulant activity was evaluated by the innovative Thrombin Generation Assay by Calibrated Automated Thrombogram method and using traditional coagulometric tests: prothrombin time, activated partial thromboplastin time, and plasma fibrinogen measurement.

RESULTS

Extracts and fractions prolonged the coagulation time in all the tests and reduced thrombin formation in thrombin generation assay. Coagulation times with the addition of ethanloic extract (2.26 mg/mL) was 17.78s, 46.43s and 14.25s respectively in prothrombin time, activated partial thromboplastin time and fibrinogren plasma measurement. In thrombin generation test, this same extract showed ETP as 323 nM/min compared to control (815 nM/min) with high tissue factor and 582 nM/min compared to control (1147 nM/min) using low tissue factor. Presence of flavonoids, phenylpropanoids, and triterpenes were confirmed by chromatographic methods and 13 compounds were identified by UPLC-ESI-MS. Based on these results and on the scientific literature, it is possible to propose that phenylpropanoids and flavonoids are related to the anticoagulant activity observed.

CONCLUSION

The results demonstrate the in vitro anticoagulant activity of L. alba, probably due to the activation of intrinsic and extrinsic pathways. It is concluded, then, that there is a potential for interaction, which needs to be further studied, between L. alba and warfarin. Also, this medicinal species shows a great potential for use in the development of new antithrombotics.

Anticoagulant and antiplatelet activity of aqueous extracts of Citrus sinensis and Lippia alba : interactions and potential for the development of antithrombotics

Citrus sinensis and Lippia alba are herbal medicines widely used in the form of tea (infusion, decoction), which ethanolic extracts have already shown great anticoagulant activity in vitro . For this reason, they seem to be excellent candidates for the development of new antithrombotics and also have the potential to interact with them. The aim of this study was to evaluate the activity of aqueous extracts in blood coagulation and platelet aggregation, in addition to analysing the micromolecular composition of these species. Thrombin generation test (TGT) by the Calibrated Automated Thrombogram method and Platelet Aggregation Test by turbidimetry were performed to evaluate the biological activities, while the chemical composition was qualitatively evaluated using high-performance liquid chromatography. Aqueous extracts were elaborated according to the folk use. All extracts were effective in reducing thrombin formation in TGT. Infusion of L. alba and infusion and decoction of C. sinensis at a concentration of 0.6 mg/ml significantly reduced platelet aggregation induced by ADP, and only the decoction of L. alba at the same concentration was able to significantly reduce collagen-induced platelet aggregation. The presence of phenylpropanoids and flavonoids in C. sinensis and L. alba extracts was verified. Furthermore, hesperidin was identified in C. sinensis through coinjection. C. sinensis and L. alba are rich in phenolics and demonstrated an in-vitro effect on important processes of haemostasis (blood coagulation, platelet agreggation), corroborating the potential of C. sinensis and L. alba for the development of antithrombotics and interact with them.

Pharmacy practitioners' practice, awareness and knowledge about herbal products and their potential interactions with cardiovascular drugs

Background: Herbal medicine use is widespread among patients, as community pharmacies may provide such products. Therefore, pharmacy practitioners should be aware of potential herbal products' adverse effects and herb-drug interactions, particularly with medications for comorbid diseases, such as cardiovascular drugs, in which pharmacy practitioners need to have good knowledge to provide patients with relevant advice to get optimal and safe therapeutic outcomes. Accordingly, the study is designed to assess the knowledge and awareness of pharmacy practitioners regarding herbal product dispensing and cardiovascular drug interaction in Jordan and view their role in patients' counselling to set up safe and effective drug use. Methods: A cross-sectional study was conducted in Jordan using an online formatted questionnaire distributed to pharmacy practitioners working in community pharmacies. Descriptive and analytical statistics were performed for the responses using the Statistical Package for the Social Sciences (SPSS) software, version 26. Results: Out of 508 participants, 41.7% had medium knowledge of herbal products pertaining mainly to university education (68.1%); 55.1% of participants dispensed herbal products without prescriptions for obesity and weight reduction (72.8%) and gastrointestinal problems (70.9%); this is because respondents agreed that herbal remedies are safe (28.5%) and effective (38.4%). Whilst the knowledge level of respondents about herbal medicine interaction with cardiovascular medication was medium, with a mean of 1.94, as this interaction may result in potentially serious consequences, 40.7% of respondents strongly agreed to gain more knowledge about the side effects of herbal products and medicine interactions through educational courses. Conclusions: The pharmacy practitioners had medium knowledge of herbal products; however, more attention should be paid to herb-drug interactions in the pharmacy educational curriculum. Additionally, pharmacy practitioners need to refresh their knowledge by attending periodic educational courses and by using reliable resources for information about herbal products in order to provide effective and competent pharmaceutical care.

Natural Products in Cardiovascular Diseases: The Potential of Plants from the Allioideae Subfamily (Ex-Alliaceae Family) and Their Sulphur-Containing Compounds

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide and, together with associated risk factors such as diabetes, hypertension, and dyslipidaemia, greatly impact patients' quality of life and health care systems. This burden can be alleviated by fomenting lifestyle modifications and/or resorting to pharmacological approaches. However, due to several side effects, current therapies show low patient compliance, thus compromising their efficacy and enforcing the need to develop more amenable preventive/therapeutic strategies. In this scenario, medicinal and aromatic plants are a potential source of new effective agents. Specifically, plants from the Allioideae subfamily (formerly Alliaceae family), particularly those from the genus Allium and Tulbaghia, have been extensively used in traditional medicine for the management of several CVDs and associated risk factors, mainly due to the presence of sulphur-containing compounds. Bearing in mind this potential, the present review aims to gather information on traditional uses ascribed to these genera and provide an updated compilation of in vitro and in vivo studies validating these claims as well as clinical trials carried out in the context of CVDs. Furthermore, the effect of isolated sulphur-containing compounds is presented, and whenever possible, the relation between composition and activity and the mechanisms underlying the beneficial effects are pointed out.

Drug-Drug Interactions With Over-The-Counter Medicines: Mind the Unprescribed

BACKGROUND

This review provides a summary of the currently available clinical data on drug-drug interactions (DDIs) involving over-the-counter (OTC) medicines. It aims to educate and increase awareness among health care providers and to support decisions in daily practice.

METHODS

An extensive literature search was performed using bibliographic databases available through PubMed.gov. An initial structured search was performed using the keywords "drug-drug-interaction AND (over-the-counter OR OTC)," without further restrictions except for the language. The initial results were screened for all described DDIs involving OTC drugs, and further information was gathered specifically on these drugs using dedicated database searches and references found in the bibliography from the initial hits.

RESULTS

From more than 1200 initial hits (1972-June 2021), 408 relevant publications were screened for DDIs involving OTC drugs, leading to 2 major findings: first, certain types of drug regimens are more prone to DDIs or have more serious DDI-related consequences, such as antiretroviral, anti-infective, and oral anticancer therapies. Second, although most DDIs involve OTC drugs as the perpetrators, some prescription drugs (statins or phosphodiesterase-5 inhibitors) that currently have OTC status can be identified as the victims in DDIs. The following groups were identified to be frequently involved in DDIs: nonsteroidal anti-inflammatory drugs, food supplements, antacids, proton-pump inhibitors, H2 antihistamines, laxatives, antidiarrheal drugs, and herbal drugs.

CONCLUSIONS

The most significant finding was the lack of high-quality evidence for commonly acknowledged interactions. High-quality interaction studies involving different phenotypes in drug metabolism (cytochrome P450) and distribution (transporters) are urgently needed. This should include modern and critical drugs, such as oral anticancer medications and direct oral anticoagulants.

Current update on herbal sources of antithrombotic activity—a comprehensive review

Background

Herbs are commonly used to treat cardiovascular diseases in various traditional medicine. On the other hand, herb-drug interactions are most commonly encountered with conventional antiplatelet and anticoagulant drug prescriptions. This review presents a compilation of plants investigated for antiplatelet and anticoagulation recently and enumerates their possible lead compounds responsible for its action for paving further drug discovery and knowledge update.

Main body of the abstract

Information about the herbs was withdrawn from the PubMed database of the previous 5 years. We also hand-searched the bibliography of relevant articles for the acquisition of additional information. About 72 herbal sources were identified with the effect of antiplatelet activity, antithrombotic activity, and anticoagulant activity. Bioactive compounds and various secondary metabolites responsible for it, such as alkaloids, saponins, flavonoids, coumarins, polyphenols, furan derivatives, iridoid glycosides, sesquiterpenes, aporphine compounds, were reported.

Conclusion

Newer pharmacological moieties are needed to prevent or reduce the adverse effects of current anti-thrombotic agents and to improve the safety of patients and cost-effectiveness.

Dry Needling and Antithrombotic Drugs

Many clinicians increasingly use dry needling in clinical practice. However, whether patients' intake of antithrombotic drugs should be considered as a contraindication for dry needling has not been investigated to date. As far as we know, there are no publications in analyzing the intake of antiplatelet or anticoagulant agents in the context of dry needling techniques. A thorough analysis of existing medications and how they may impact various needling approaches may contribute to improved evidence-informed clinical practice. The primary purpose of this paper is to review the current knowledge of antithrombotic therapy in the context of dry needling. In addition, reviewing guidelines of other needling approaches, such as electromyography, acupuncture, botulinum toxin infiltration, and neck ultrasound-guided fine-needle aspiration biopsy, may provide specific insights relevant for dry needling. Based on published data, taking antithrombotic medication should not be considered an absolute contraindication for dry needling techniques. As long as specific dry needling and individual risks are properly considered, it does not change the risk and safety profile of dry needling. Under specific circumstances, the use of ultrasound guidance is recommended when available.

Interactions between Food and Drugs, and Nutritional Status in Renal Patients: A Narrative Review

Drugs and food interact mutually: drugs may affect the nutritional status of the body, acting on senses, appetite, resting energy expenditure, and food intake; conversely, food or one of its components may affect bioavailability and half-life, circulating plasma concentrations of drugs resulting in an increased risk of toxicity and its adverse effects, or therapeutic failure. Therefore, the knowledge of these possible interactions is fundamental for the implementation of a nutritional treatment in the presence of a pharmacological therapy. This is the case of chronic kidney disease (CKD), for which the medication burden could be a problem, and nutritional therapy plays an important role in the patient’s treatment. The aim of this paper was to review the interactions that take place between drugs and foods that can potentially be used in renal patients, and the changes in nutritional status induced by drugs. A proper definition of the amount of food/nutrient intake, an adequate definition of the timing of meal consumption, and a proper adjustment of the drug dosing schedule may avoid these interactions, safeguarding the quality of life of the patients and guaranteeing the effectiveness of drug therapy. Hence, a close collaboration between the nephrologist, the renal dietitian, and the patient is crucial. Dietitians should consider that food may interact with drugs and that drugs may affect nutritional status, in order to provide the patient with proper dietary suggestions, and to allow the maximum effectiveness and safety of drug therapy, while preserving/correcting the nutritional status.

Bioactivity Potential of Aesculus hippocastanum L. Flower: Phytochemical Profile, Antiradical Capacity and Protective Effects on Human Plasma Components under Oxidative/Nitrative Stress In Vitro

Horse chestnut (Aesculus hippocastanum) flower is a traditional medicine applied to alleviate symptoms of chronic venous insufficiency (CVI). However, its flavonoid-based composition has not been sufficiently recognized, and the data supporting its traditional application are lacking. In the work, 43 constituents were detected by UHPLC-PDA-ESI-TQ-MS/MS (flavonoids, phenolic acids, flavanols, and coumarins), including 31 reported in the flower for the first time. The quantitative HPLC-PDA study (developed and validated for quality control purposes) indicated the fractionated extraction as an efficient method for enhancing the total polyphenol content (TPHC) in the extracts (up to 414.06 mg/g) and kaempferol glycosides as their dominant constituents (75.05-82.14% TPHC). The activity studies showed significant scavenging properties of the extracts and their constituents towards reactive oxygen species (especially against highly reactive hydroxyl radical, with capacities up to 7.85 mmol ascorbic acid equivalents/g). Moreover, the analytes relevantly protected human plasma biomolecules from peroxynitrite-induced oxidative/nitrative damage; at 1-50 µg/mL, they hindered the protein nitration and lipid peroxidation, decreasing the levels of 3-nitrotyrosine (by up to 50%) and thiobarbituric acid reactive substances (by up to 70%), respectively. The extracts also averted the depletion of plasma thiols (by up to 67%) and improved the non-enzymatic antioxidant capacity of plasma. The demonstrated mechanisms might be partly responsible for the efficacy of the flower in CVI. Additionally, the anti-aggregatory and anticoagulant properties of the extracts were found only mild or negligible, which suggests that they may be safely applied with drugs impacting the coagulation process.

Genetic and Nongenetic Determinants of Variable Warfarin Dose Requirements: A Report from North India

INTRODUCTION

Warfarin is widely used and will continue to be prescribed especially in developing countries due to its low cost. Given the huge patient load requiring anticoagulation, there is a need to develop strategies to optimize warfarin therapy for ensuring safe and effective anticoagulation. In the present work, we aimed at elucidating the association of genetic and nongenetic variables with warfarin dose requirement in patients attending the cardiovascular clinic in a tertiary care center of North India.

METHODS

This was a prospective study conducted over 1 year. Patient demographic and clinical details were captured in customized case record forms. Genotyping was done using the polymerase chain reaction-restriction fragment length polymorphism method. Pharmacogenetic influence of CYP2C9 (rs1799853 and rs1057910) and VKORC1 (rs9923231) variant alleles was studied. The association of genetic and nongenetic factors with warfarin dose was quantified using a stepwise multivariate linear regression model.

RESULTS

Two hundred and forty patients were screened. Data from 82 eligible patients were used for quantifying the association of genetic and nongenetic factors with warfarin dose. A descriptive model based on CYP2C9*3 (rs1057910) and VKORC1 (rs9923231) variant alleles and BMI was developed. The model explains nearly half of the interindividual variation in warfarin dose requirement.

CONCLUSION

The model explains nearly half of the interindividual variation in warfarin dose in patients with atrial fibrillation and or requiring valve replacement.

DDInter: an online drug-drug interaction database towards improving clinical decision-making and patient safety

Drug-drug interaction (DDI) can trigger many adverse effects in patients and has emerged as a threat to medicine and public health. Despite the continuous information accumulation of clinically significant DDIs, there are few open-access knowledge systems dedicated to the curation of DDI associations. To facilitate the clinicians to screen for dangerous drug combinations and improve health systems, we present DDInter, a curated DDI database with comprehensive data, practical medication guidance, intuitive function interface, and powerful visualization to the scientific community. Currently, DDInter contains about 0.24M DDI associations connecting 1833 approved drugs (1972 entities). Each drug is annotated with basic chemical and pharmacological information and its interaction network. For DDI associations, abundant and professional annotations are provided, including severity, mechanism description, strategies for managing potential side effects, alternative medications, etc. The drug entities and interaction entities are efficiently cross-linked. In addition to basic query and browsing, the prescription checking function is developed to facilitate clinicians to decide whether drugs combinations can be used safely. It can also be used for informatics-based DDI investigation and evaluation of other prediction frameworks. We hope that DDInter will prove useful in improving clinical decision-making and patient safety. DDInter is freely available, without registration, at http://ddinter.scbdd.com/.

Mechanisms and interactions in concomitant use of herbs and warfarin therapy: An updated review

This review is an updated and expanded version published in this journal in 2016. Warfarin pharmacotherapy is extremely complex, since in addition to being a low therapeutic index drug, it does not follow the dose-response pattern and has characteristics that predispose the occurrence of interactions, such as high binding rate to plasma proteins, metabolization by cytochrome P450 enzymes, further to acting in the complex process of blood coagulation, platelet activation, and inflammation. For these reasons, warfarin has great potential for interaction with drugs, foods, and herbal medicines. Herb-warfarin interactions, however, are still not very well studied; thus, the objective of this update is to present new information on the subject aiming to provide a scientific basis to help health professionals in the clinical management of these interactions. A literature review was performed from May to June 2021 in multiple databases and articles published in 2016 to 2021 were included. A total of 59 articles describing 114 herbal medicines were reported to interact with warfarin. Of the plants mentioned, 84% had the potential to increase warfarin effect and the risk of bleeding. Targets possibly involved in these interactions include the processes of blood coagulation, platelet activation, and inflammation, in addition to the pharmacokinetics and pharmacodynamics of warfarin. Despite these alarming numbers, however, the clinical management of interactions is known to be effective. Thus, it is important that the use of these herbal medicines be done with caution in anticoagulated patients and that studies of herb-drug interactions be encouraged in order to generate information to support the clinical management of patients.

The Effect of Wheatgrass Lyophilizate on Blood Clotting Time in Rats

Wheatgrass is widely used in the alternative medicine, however, there is a lack of clinical evidence to support its efficacy. Although based on its chemical composition, data from animal experiments and clinical trials, the use of juice and extracts of Triticum shoots seems to be safe, clinical reports point out its potential interaction with oral anticoagulants. The aim of our study was to assess the interaction of wheatgrass with warfarin in rats and to assess its flavonoid content. Three groups of animals were treated orally with wheatgrass, warfarin, or the combination of wheatgrass and warfarin for five days. Clotting assays were performed using platelet-poor plasma. Prothrombin time was determined by optical and mechanical coagulometers. Flavonoid content of wheatgrass was measured by HPLC. The effect of wheatgrass on prothrombin time was not confirmed. Co-administration of wheatgrass and warfarin did not result in diminished anticoagulant activity. Low amount of flavonoids was detected in wheatgrass juice, the total flavonoid content was 0.467 mg/100 g lyophilized juice powder. The previously reported rutin, quercetin and apigenin was not detected by us. Our results do not confirm the probability of interaction of wheatgrass with oral anticoagulants. However, the low flavonoid content of wheatgrass does not support its use as an antioxidant.

Probe into the Molecular Mechanism of Ibuprofen Interaction with Warfarin Bound to Human Serum Albumin in Comparison to Ascorbic and Salicylic Acids: Allosteric Inhibition of Anticoagulant Release

The release of anticoagulant drugs such as warfarin from human serum albumin (HSA) has been important not only mechanistically but also clinically for patients who take multiple drugs simultaneously. In this study, the role of some commonly used drugs, including s-ibuprofen, ascorbic acid, and salicylic acid, was investigated in the release of warfarin bound to HSA in silico. The effects of the aforementioned drugs on the HSA-warfarin complex were investigated with molecular dynamics (MD) simulations using two approaches; in the first perspective, molecular docking was used to model the interaction of each drug with the HSA-warfarin complex, and in the second approach, drugs were positioned randomly and distant from the binary complex (HSA-warfarin) in a physiologically relevant concentration. The results obtained from both approaches indicated that s-ibuprofen and ascorbic acid both displayed allosteric effects on the release of warfarin from HSA. Although ascorbic acid aided in warfarin release, leading to destabilization of HSA, ibuprofen demonstrated a stabilizing effect on releasing the anticoagulant drug through several noncovalent interactions, including hydrophobic, electrostatic, and hydrogen-bonding interactions with the protein. The calculated binding free energy and energy contribution of involved residues using the molecular mechanics-Poisson Boltzmann surface area (MM-PBSA) method, along with root mean square deviation (RMSD) values, protein gyration, and free energy surface (FES) mapping of the protein, provided valuable details on the nature of the interactions of each drug on the release of warfarin from HSA. These results can provide important information on the mechanisms of anticoagulant release that has not been revealed in molecular details previously.

In vitro anticoagulant activity of selected medicinal plants: potential interactions with warfarin and development of new anticoagulants

OBJECTIVES

Warfarin is the most widely used anticoagulant in the world, but it has several limitations including its narrow therapeutic range, need for dose adjustment and high potential for interactions. The simultaneous use of other drugs or even medicinal plants and certain foods could interfere with its therapeutic activity. In this context, this study aims to investigate the in vitro anticoagulant potential and phytochemical constitution of 17 plants selected from a previous clinical cross-sectional study (2014), that investigated the habits of plant utilization among patients taking warfarin.

METHODS

Ethanol extracts and essential oils were evaluated, in vitro, as to their effect in the prothrombin time (PT) and activated partial thromboplastin time (aPTT) tests. Four species that presented aPTT >50 s were selected for phytochemical evaluation.

RESULTS

Thirteen of the 17 plants selected demonstrated a significant anticoagulant effect in at least one of the evaluated parameters. Citrus sinensis (PT=14.75 and aPTT=53.15), Mentha crispa (aPTT=51.25), Mikania laevigata (PT=14.90 and aPTT=52.10), and Nasturtium officinale (aPTT=50.55) showed greater anticoagulant potential compared to normal plasma pool (PT=12.25 and aPTT=37.73). Chemical profiles of these four species were obtained, and certain compounds were identified: rosmarinic acid from M. crispa and isoorientin from N. officinale.

CONCLUSIONS

Thus, the results of this study could be a useful indicator for clinical practice towards the possibility of interaction between these plants and anticoagulants, although further clinical research is needed taking into consideration the limitations of in vitro studies. These findings also suggest that further research into the action of these plants could be of real clinical value in identifying potential alternative anticoagulant therapies.

Updates on Anticoagulation and Laboratory Tools for Therapy Monitoring of Heparin, Vitamin K Antagonists and Direct Oral Anticoagulants

Anticoagulant drugs have been used to prevent and treat thrombosis. However, they are associated with risk of hemorrhage. Therefore, prior to their clinical use, it is important to assess the risk of bleeding and thrombosis. In case of older anticoagulant drugs like heparin and warfarin, dose adjustment is required owing to narrow therapeutic ranges. The established monitoring methods for heparin and warfarin are activated partial thromboplastin time (APTT)/anti-Xa assay and prothrombin time – international normalized ratio (PT-INR), respectively. Since 2008, new generation anticoagulant drugs, called direct oral anticoagulants (DOACs), have been widely prescribed to prevent and treat several thromboembolic diseases. Although the use of DOACs without routine monitoring and frequent dose adjustment has been shown to be safe and effective, there may be clinical circumstances in specific patients when measurement of the anticoagulant effects of DOACs is required. Recently, anticoagulation therapy has received attention when treating patients with coronavirus disease 2019 (COVID-19). In this review, we discuss the mechanisms of anticoagulant drugs—heparin, warfarin, and DOACs and describe the methods used for the measurement of their effects. In addition, we discuss the latest findings on thrombosis mechanism in patients with COVID-19 with respect to biological chemistry.

Effects of Herba Erigerontis injection on pharmacodynamics and pharmacokinetics of warfarin in rats in vivo

Herba Erigerontis injection (HEI) is an aqueous solution derived from whole plants of Erigeron breviscapus, which may be co-administered with warfarin to treat cardiovascular and cerebrovascular disorders. This research was conducted to make sure whether HEI would affect anticoagulation of warfarin to guarantee reasonable medication. The pharmacodynamic study was designed to measure prothrombin time (PT) and activated partial thromboplastin time (APTT) values, and international normalized ratio (INR) values were calculated. For pharmacokinetic study, ultra performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) technology was applied to measure plasma concentrations of warfarin enantiomers. The influence of HEI on plasma protein binding rate of warfarin was assessed by ultrafiltration. Pharmacodynamic study demonstrated that both HEI alone and co-administered with warfarin could increase PT and INR values significantly (P < .01), whereas the APTT values were unaffected (P > .05). Pharmacokinetic study manifested that C_max , AUC and t_1/2 prolonged significantly (P < .01) for R/S-warfarin in presence of HEI. Low (3.6 mL/kg), medium (7.2 mL/kg) and high (10.8 mL/kg) doses of HEI could decrease plasma protein binding rate of warfarin significantly (P < .01). The results mean that HEI can potentiate the anticoagulant response of warfarin through both pharmacodynamics and pharmacokinetics.

Cytotoxic Effects of Mesaconitine, the Aconitum carmichaelii Debx Bioactive Compound, on HBEC-5i Human Brain Microvascular Endothelial Cells: Role of Ca2+ Signaling-Mediated Pathway

Mesaconitine, one of Aconitum carmichaelii Debx bioactive compounds, was shown to evoke Ca²⁺ homeostasis and its related physiological effects in endothelial cell types. However, the effect of mesaconitine on Ca²⁺ signaling and cell viability in human brain microvascular endothelial cells is unclear. This study focused on exploring whether mesaconitine changed cytosolic Ca²⁺ concentrations ([Ca²⁺]_i), affected cell viability, and established the relationship between Ca²⁺ signaling and viability in HBEC-5i human brain microvascular endothelial cells. In HBEC-5i cells, cell viability was measured by the cell proliferation reagent (WST-1). [Ca²⁺]_i was measured by the Ca²⁺-sensitive fluorescent dye fura-2. Mesaconitine (10-100 μM) concentration dependently induced [Ca²⁺]_i rises. Ca²⁺ removal reduced the signal by approximately 25%. Mesaconitine (40-100 μM) caused cytotoxicity in HBEC-5i cells. This cytotoxic response was significantly reversed by chelation of cytosolic Ca²⁺ with BAPTA/AM. In Ca²⁺-containing medium, mesaconitine-induced Ca²⁺ entry was inhibited by 25% by modulators of store-operated Ca²⁺ channels and protein kinase C (PKC). Furthermore, mesaconitine also induced Mn²⁺ influx suggesting of Ca²⁺ entry. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin abolished mesaconitine-evoked [Ca²⁺]_i rises. Conversely, treatment with mesaconitine abolished thapsigargin-evoked [Ca²⁺]_i rises. Inhibition of phospholipase C (PLC) with U73122 abolished mesaconitine-induced [Ca²⁺]_i rises. In sum, mesaconitine caused cytotoxicity that was triggered by preceding [Ca²⁺]_i rises. Furthermore, mesaconitine induced [Ca²⁺]_i rises by evoking Ca²⁺ entry via PKC-sensitive store-operated Ca²⁺ channels and PLC-dependent Ca²⁺ release from the endoplasmic reticulum. It suggests that Ca²⁺ signaling have a potential cytotoxic effect on mesaconitine-treated human brain microvascular endothelial cells.

Reduced Stroke Risk among Patients with Atrial Fibrillation Receiving Chinese Herbal Medicines Treatment: Analysis of Domestic Data in Taiwan

Background and objectives: Patients with atrial fibrillation (AF) reportedly have a much higher risk of death due to stroke. Faced with this heavy burden, it remains unclear if the Chinese herbal medicines (CHMs), the most common form complementary and alternative medicine, can lower the risk of stroke for them. This study aimed to evaluate the association of CHMs use with stroke risk among them. Materials and Methods: From a nationwide database, 11,456 AF patients aged ≧ 20 years between 1998 and 2007 were identified. Afterwards, we enrolled 2670 CHMs users and randomly selected 2670 non-CHMs users using the propensity score method. The occurrence of stroke was recorded until the end of 2012. Results: Within the follow-up period, 671 CHMs users and 900 non-CHMs users developed stroke, with incidence rates of 33.02 and 45.46 per 1000 person-years, respectively. CHMs use was associated with a 30% lower stroke risk, especially for those receiving CHMs for over two years. Conclusions: The findings of the present study suggest that adding CHMs to conventional therapy could decrease subsequent stroke risk for AF patients. It is also suggested that prospective randomized trials are needed to further clarify if the detected association revealed in this study supports a causal link, and to identify the specific CHMs that may be beneficial to AF patients.

Functionally Significant Coumarin-Related Variant Alleles and Time to Therapeutic Range in Chilean Cardiovascular Patients

Despite the development of new oral agents over the last decade, vitamin K antagonists (VKAs) remain the most widely used anticoagulants for treating and preventing thromboembolism worldwide. In Chile, the Ministry of Health indicates that acenocoumarol should be used in preference to any other coumarin. Complications of inappropriate dosing are among the most frequently reported adverse events associated with this medication. It is well known that polymorphisms in pharmacokinetic and pharmacodynamic proteins related to coumarins (especially warfarin) influence response to these drugs. This work analyzed the impact of CYP2C19*2 (rs4244285), CYP1A2*1F (rs762551), GGCx (rs11676382), CYP2C9*2 (rs1799853), CYP2C9*3 (rs1057910), CYP4F2 (rs2108622), VKORC1 (rs9923231), VKORC1 (rs7294), CYP3A4*1B (rs2740574), and ABCB1 (rs1045642) polymorphisms on time to therapeutic range for oral anticoagulants in 304 Chilean patients. CYP2C9*3 polymorphisms were associated with time to therapeutic range for acenocoumarol in Chilean patients, and the CYP4F2 TT genotype, MDR1 A allele, CYP1A2 A allele, and CYP3A4T allele are promising variants that merit further analysis. The presence of polymorphisms explained only 4.1% of time to therapeutic range for acenocoumarol in a multivariate linear model. These results improve our understanding of the basis of ethnic variations in drug metabolism and response to oral anticoagulant therapy. We hope that these findings will contribute to developing an algorithm for VKA dose adjustment in the Chilean population in the near future, decreasing the frequency of stroke, systemic embolism, and bleeding-related adverse events.

Decrease in Efficacy of Warfarin as a Result of Drug-Drug Interaction (Case Report)

The one of the main aims in modern clinical pharmacology is to provide safe and effective therapy considering a frequent administration of several drugs having different drug-drug interactions. Warfarin belongs to the number of popular anticoagulants which along with its efficiency not infrequently alters anticoagulant characteristics when administered with other drugs and food products. A case of a decrease in the efficacy of warfarin in a patient with mitral stenosis while taking a combined choleretic drug is presented in the article. The components of this choleretic drug (dry animal bile, dry garlic extract, dry nettle extract, activated charcoal) could impair the absorption of warfarin, increase intestinal absorption of vitamin K, and have a negative effect on the anticoagulant effect of warfarin. Management of patients receiving anticoagulants should be performed in accordance with clinical recommendations. Prescription of drugs, including multicomponent ones, without proven efficacy, for such patients should be considering the potential drug interaction.

A study to evaluate herb-drug interaction underlying mechanisms: An investigation of ginsenosides attenuating the effect of warfarin on cardiovascular diseases

Warfarin and ginseng have been widely used in the treatment of cardiovascular diseases. However, the clinical safety and effectiveness of herb-drug combination treatment are still controversial. Therefore, it is very essential to probe the interaction between warfarin and ginseng. In this study, in vitro and in vivo study was carried out to demonstrate that whether there is an interaction between warfarin and ginsenosides (GS), which is the main component of ginseng. In vitro study showed that the adhesion ability between endothelial cells and matrigel/platelets was enhanced due to the up-regulating expression of intercellular adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1) proteins by treatment of warfarin+GS combination compared to warfarin/GS treatment alone. Moreover, GS could weaken the anticoagulation effect of warfarin in hyperlipemia rats owning to the increased expression levels of coagulation factors and hepatic cytochrome P450 enzymes in plasma after long-term co-administration of warfarin with GS. The results of both in vitro and in vivo study demonstrated that there is a serious interaction between warfarin and ginseng, which may deteriorate atherosclerosis and thrombosis after combined use of warfarin and GS.

Thrombin generation test with the calibrated automated thrombogram and anticoagulant activity of Mentha crispa

: Evaluate the in-vitro effect of Mentha crispa extract on blood coagulation, compare the conventional coagulometric tests with thrombin generation test (TGT), and study the qualitative micromolecular composition of M. crispa. Extract of M. crispa was incubated with plasma and used in the coagulometric tests: prothrombin and activated partial thromboplastin times, fibrinogen, and TGT. A phytochemical prospection was performed to evaluate the chemical composition of this extract. The extract was efficient in prolonging prothrombin time and activated partial thromboplastin time, and reducing fibrinogen levels and TGT parameters, indicating that the extract of M. crispa inhibited the intrinsic and extrinsic pathways of blood coagulation. The results obtained in TGT are in agreement with the results of conventional coagulometric tests and the in-vitro anticoagulant activity of M. crispa suggests that its use by patients using oral anticoagulants deserves caution.

A New Strategy for Identifying Mechanisms of Drug-drug Interaction Using Transcriptome Analysis: Compound Kushen Injection as a Proof of Principle

Drug-drug interactions (DDIs), especially with herbal medicines, are complex, making it difficult to identify potential molecular mechanisms and targets. We introduce a workflow to carry out DDI research using transcriptome analysis and interactions of a complex herbal mixture, Compound Kushen Injection (CKI), with cancer chemotherapy drugs, as a proof of principle. Using CKI combined with doxorubicin or 5-Fu on cancer cells as a model, we found that CKI enhanced the cytotoxic effects of doxorubicin on A431 cells while protecting MDA-MB-231 cells treated with 5-Fu. We generated and analysed transcriptome data from cells treated with single treatments or combined treatments and our analysis showed that opposite directions of regulation for pathways related to DNA synthesis and metabolism which appeared to be the main reason for different effects of CKI when used in combination with chemotherapy drugs. We also found that pathways related to organic biosynthetic and metabolic processes might be potential targets for CKI when interacting with doxorubicin and 5-Fu. Through co-expression analysis correlated with phenotype results, we selected the MYD88 gene as a candidate major regulator for validation as a proof of concept for our approach. Inhibition of MYD88 reduced antagonistic cytotoxic effects between CKI and 5-Fu, indicating that MYD88 is an important gene in the DDI mechanism between CKI and chemotherapy drugs. These findings demonstrate that our pipeline is effective for the application of transcriptome analysis to the study of DDIs in order to identify candidate mechanisms and potential targets.

Factors influencing communication of traditional Chinese medicine use between patients and doctors: A multisite cross-sectional study

OBJECTIVE

In Singapore, the use of traditional Chinese medicine (TCM) alongside Western medicine (WM) is common. There are risks of adverse herb-drug interactions when taken concurrently. Current literature suggests that TCM use is not regularly reported to WM doctors in Singapore, but the underlying reasons are not understood.

METHODS

A cross-sectional study was conducted across Singapore by administering questionnaires to TCM-using patients and WM-practising general practitioners (GPs). The questionnaire examined the following themes: (1) demographics and TCM use pattern; (2) respondents' (patients and GPs) knowledge and beliefs about TCM and the factors influencing the discussion of TCM during the WM consultation; and (3) respondents' qualitative suggestions to increase disclosure rate.

RESULTS

A total of 484 patients and 334 GPs were surveyed. Factors associated with patients' initiation of TCM discussion include length of consultation (odds ratio [OR]: 2.1; P < 0.001), comfort level in discussing TCM (OR: 1.6; P < 0.001) and belief in importance of discussion (OR: 1.4; P = 0.017). Doctor's initiation of discussion (74%) was the top patient-ranked factor influencing their discussion of TCM. For doctors, knowledge of TCM indications (OR: 2.2; P < 0.001), belief in importance of discussion (OR: 2.1; P < 0.001) and comfort level in discussing TCM (OR: 1.9; P = 0.001) were associated with their initiation of TCM use discussion. Possible WM-TCM interactions (58%) was the top doctor-ranked factor influencing their discussion of TCM.

CONCLUSION

The discussion of TCM in a WM setting is multifactorial. Interventions include doctors' active screening for TCM use in patients and equipping doctors with TCM knowledge. Improving communication between patients and doctors is key to avoiding harmful herb-drug interactions.

Reviewing the mechanisms of natural product-drug interactions involving efflux transporters and metabolic enzymes

The World Health Organization (WHO) and other worldwide health agencies have recently taken initiatives to encourage the use of traditional medicine and/or complementary/alternative medicine in order to promote well-being and public health. In this way, one of the WHO's concerns is the safe use of these therapies. Phytotherapy is a strategy consisting of the use of medicinal plants (MP) and/or herbal medicinal products (HMP) for medicinal purposes. The use of phytotherapy concomitantly with drugs may cause interactions compromising the expected pharmacological action or generating toxic effects. These interactions are complex processes that may occur with multiple medications targeting different metabolic pathways, and involving different compounds present in MP and HMP. Thus, the aim of this review was to summarize the main MP- and HMP-drug interactions that involve specific transporters (P-glycoprotein and BCRP) and CYP450 enzymes (CYP3A4 and CYP2D6), which play relevant roles in the mechanisms of interactions. Firstly, multiple databases were used to search studies describing in vitro or in vivo MP and HMP-drug interactions and, after that, a systematic note-taking and appraisal of the literature was conducted. It was observed that several MP and HMP, metabolic pathways and transcription factors are involved in the transporters and enzymes expression or in the modulation of their activity having the potential to provide such interactions. Thus, the knowledge of MP- and HMP-drug interaction mechanisms could contribute to prevent harmful interactions and can ensure the safe use of these products to help the establishment of the therapeutic planning in order to certify the best treatment strategy to be used.

Interactions of ginseng with therapeutic drugs

Ginseng is the most frequently used herbal medicine for immune system stimulation and as an adjuvant with prescribed drugs owing to its numerous pharmacologic activities. It is important to investigate the beneficial effects and interaction of ginseng with therapeutic drugs. This review comprehensively discusses drug metabolizing enzyme- and transporter-mediated ginseng-drug interaction by analyzing in vitro and clinical results with a focus on ginsenoside, a pharmacologically active marker of ginseng. Impact of ginseng therapy or ginseng combination therapy on diabetic patients and of ginseng interaction with antiplatelets and anticoagulants were evaluated based on ginseng origin and ginsenoside content. Daily administration of Korean red ginseng (0.5-3 g extract; dried ginseng > 60%) did not cause significant herb-drug interaction with drug metabolizing enzymes and transporters. Among various therapeutic drugs administered in combination with ginseng, adjuvant chemotherapy, comprising ginseng (1-3 g extract) and anticancer drugs, was effective for reducing cancer-related fatigue and improving the quality of life and emotional scores. Limited information regarding ginsenoside content in each ginseng product and plasma ginsenoside concentration among patients necessitates standardization of ginseng product and establishment of pharmacokinetic-pharmacodynamic correlation to further understand beneficial effects of ginseng-therapeutic drug interactions in future clinical studies.

Pharmacokinetic Interactions between Cardiovascular Medicines and Plant Products

The growing use of plant products among patients with cardiovascular pharmacotherapy raises the concerns about their potential interactions with conventional cardiovascular medicines. Plant products can influence pharmacokinetics or/and pharmacological activity of coadministered drugs and some of these interactions may lead to unexpected clinical outcomes. Numerous studies and case reports showed various pharmacokinetic interactions that are characterized by a high degree of unpredictability. This review highlights the pharmacokinetic clinically relevant interactions between major conventional cardiovascular medicines and plant products with an emphasis on their putative mechanisms, drawbacks of herbal products use, and the perspectives for further well-designed studies.

Metals and metalloids in traditional medicines (Ayurvedic medicines, nutraceuticals and traditional Chinese medicines)

Traditional medicine (TM) including Ayurvedic medicines, traditional Chinese medicines and nutraceuticals are popular across the globe as dietary supplements and traditional and alternative medicines. Health risks from these remedies continue to present serious concerns, with occurrences of poisoning by metals and metalloids present at concentrations above acceptable regulatory standards. This review overviews the prevalence of TM use, cases of metal and metalloid poisoning following TM consumption, and forms of TM contamination and adulteration. The review summarises regulations by the World Health Organization (WHO) and other relevant bodies. Finally, the review recommends how to protect consumers.

Leonurus cardiaca L. as a Source of Bioactive Compounds: An Update of the European Medicines Agency Assessment Report (2010)

Leonurus cardiaca L. (motherwort) is a perennial herb, native to Asia and southeastern Europe, with widespread global occurrence in present days. The plant was historically used as cardiotonic and for treating gynaecological afflictions (such as amenorrhea, dysmenorrhea, menopausal anxiety, or postpartum depression). Although its use in oriental and occidental medicine is relatively well documented, the recent progress registered raises the need for an update of the Medicines Agency assessment report on Leonurus cardiaca L., herba (2010). The current study presents the progress made within the 2010-2018 timeframe regarding the potential applications and scientific evidences supporting the traditional use of motherwort, in the same time suggesting future research opportunities.

Shear Mode Bulk Acoustic Resonator Based on Inclined c-Axis AlN Film for Monitoring of Human Hemostatic Parameters

Measurement of hemostatic parameters is essential for patients receiving long-term oral anticoagulant agents. In this paper, we present a shear mode bulk acoustic resonator based on an inclined c-axis aluminum nitride (AlN) film for monitoring the human hemostatic parameters. During the blood coagulation process, the resonant frequency of the device decreases along with a step-ladder profile due to the viscosity change during the formation of fibers in blood, revealing the sequential coagulation stages. Two hemostatic parameters with clinical significance, prothrombin time (PT) along with its derived measure of international normalized ratio (INR), are determined from time-frequency curves of the device. Furthermore, the resonator is compared with a commercial coagulometer by monitoring the hemostatic parameters for one month in a patient taking the oral anticoagulant. The results are consistent. In addition, thanks to the excellent potential for integration, miniaturization and the availability of direct digital signals, the proposed device has promising application for point of care coagulation monitoring.

Characteristics of patients with thromboembolic disorders on warfarin therapy in resource limited settings

Background

Warfarin is a drug with narrow therapeutic index used in the management of thromboembolic disorders. Several factors affect its plasma concentrations with a resultant risk of toxicity. We examined the database of patients on warfarin therapy in order to establish the factors that affect the stability of INR and correlated them to clinical outcomes in resource limited settings.

Methods

We analysed retrospective data of patients admitted to adult medical wards at Moi Teaching and Referral Hospital (MTRH) in 2015. Inclusion criteria were patients with thromboembolic and related disorders and on warfarin treatment. Derived data included demographics, indications for warfarin use, co-prescribed drugs, co-morbidities, INR measurements, duration of hospital stay and clinical outcomes. Descriptive statistics were used to summarize the data. Pearson’s correlation coefficient was used to assess relationships between duration of hospitalization and number of INR tests. Regression splines were used to capture INR trends during the follow up period. Data was analysed using R v. 3.3.1.

Results

A total of 310 patients had thromboembolic disorders, out of which 63 met the study criteria.

The median age was 48 years, while the mean number of INR measurements was once every four days. Majority of patients did not achieve stable INR values, with only two having consecutive INR values within therapeutic goal. Patients who died had high INR levels. The median duration of hospital stay was 9 days (IQR: 7.0, 16.5). There was a significant correlation between length of stay in hospital and the number of times that INR were measured (Corr = 0.667, p < 0.001). The two most common indications for warfarin were DVT (64.4%) and atrial fibrillation (24.7%). All the patients had one or more comorbid conditions except for 11 with DVT alone, with cardiovascular diseases and infections being the most frequent, and on concomitant medications, majority of which are known to interact with warfarin.

Conclusions

It was difficult to achieve stable INR under the prevailing conditions despite the frequent tests.

The potential factors that may have contributed to the fluctuations include drug-drug interactions, frequency of INR tests, comorbidities and the short duration of hospital stay.

Warfarin Safety: A Cross-Sectional Study of the Factors Associated with the Consumption of Medicinal Plants in a Brazilian Anticoagulation Clinic

OBJECTIVE

The aim of this study was to analyze factors associated with the consumption of medicinal plants by patients being treated with warfarin in a Brazilian anticoagulation clinic and to study the safety of medicinal plant use in patients on warfarin therapy.

METHODS

The study was performed as an observational cross-sectional analysis. Study participants were outpatients on long-term warfarin therapy for at least 2 months for atrial fibrillation or prosthetic cardiac valves. Interviews were carried out concerning information about the habits of medicinal herb consumption, and logistic regression analysis was performed to identify factors associated with the consumption of herbs. The scientific names of the medicinal plants were identified to search for information on the effects on the hemostasis of the interactions between the medicinal herbs reported and warfarin.

RESULTS

The mean age of the 273 patients included was 60.8 years; 58.7% were women. Medicinal plants were used by 67% of the participants. No association between demographic and clinical data and the use of medicinal plants was identified. Patients reported a total of 64 different plants, primarily consumed in the form of tea. The plants were mainly used to treat respiratory tract and central nervous system disorders. About 40% of the plants cited have been reported to potentially interfere with the anticoagulation therapy, principally by potentiating the effects of warfarin, which could, increase the risk of bleeding.

CONCLUSION

The use of medicinal plants was highly common and widespread in patients receiving warfarin as an anticoagulation therapy. Univariate analysis of variables associated with the consumption of herbs showed no statistically significant difference in the consumption of medicinal plants for any of the sociodemographic and clinical data. The medicinal plants that were reportedly consumed by the patients could affect hemostasis. This study reinforces the need for further studies evaluating the habits of patients consuming medicinal plants and their clinical implications, and will help to design strategies to manage the risks associated with warfarin-herbal interactions.

Interaction between Saikosaponin D, Paeoniflorin, and Human Serum Albumin

Saikosaponin D (SSD) and paeoniflorin (PF) are the major active constituents of Bupleuri Radix and Paeonia lactiflora Pall, respectively, and have been widely used in China to treat liver and other diseases for many centuries. We explored the binding of SSD/PF to human serum albumin (HSA) by using fluorospectrophotometry, circular dichroism (CD) and molecular docking. Both SSD and PF produced a conformational change in HSA. Fluorescence quenching was accompanied by a blue shift in the fluorescence spectra. Co-binding of PF and SSD also induced quenching and a conformational change in HSA. The Stern-Volmer equation showed that quenching was dominated by static quenching. The binding constant for ternary interaction was below that for binary interaction. Site-competitive experiments demonstrated that SSD/PF bound to site I (subdomain IIA) and site II (subdomain IIIA) in HSA. Analysis of thermodynamic parameters indicated that hydrogen bonding and van der Waals forces were mostly responsible for the binary association. Also, there was energy transfer upon binary interaction. Molecular docking supported the experimental findings in conformation, binding sites and binding forces.

Popular Herbal and Natural Remedies Used in Psychiatry

Natural and herbal remedies, also known as "alternative" or "complementary" medicines, have grown tremendously in popularity over the past two decades, becoming a major component of health care and general wellness in the United States and worldwide. The ready availability of these remedies over the counter and their generally good tolerability and safety contribute to this popularity, and many people have benefited from them, often in cases when conventional treatments have failed or caused intolerable side effects. Despite many Food and Drug Administration (FDA)-approved psychotropic medications on the market, efficacy has been inconsistent for some, and many treatment responders will eventually relapse. Continued research on the efficacy and safety of these alternative therapies is, therefore, important. This article reviews six of the most commonly used natural remedies for psychiatric conditions, including the antidepressants St. John's wort, omega-3 fatty acids, and S-adenosyl methionine (SAMe); the sedative-hypnotics valerian and melatonin; and the nootropic ginkgo biloba. We outline the general indications for use, suggested doses, possible mechanisms, and adverse effects to give clinicians a good summary of the benefits and liabilities of each. Although there is growing evidence of efficacy and safety to support the use of these remedies, clinicians must be aware of the limitations of the evidence base and take that into account with all the other factors that contribute to clinical decision making.

7-Hydroxylation of warfarin is strongly inhibited by sesamin, but not by episesamin, caffeic and ferulic acids in human hepatic microsomes

Warfarin is a commonly used anticoagulant drug and is a derivate of coumarin. Cytochrome P450 2C9 (CYP2C9) plays the key role in transformation of coumarin and thus, influences determination of warfarin dosage. A number of factors including dietary compounds such as sesamin, caffeic acid and ferulic acids can regulate the activity of CYP2C9. The present study tested the hypothesis that sesamin, episesamin, caffeic acid and ferulic acid decreases the rate of warfarin 7-hydroxylation via inhibition of hepatic CYP2C9. The experiments were conducted on hepatic microsomes from human donors. It was demonstrated that the rate of 7-hydroxylation of warfarin was significantly decreased in the presence of sesamin in the range of concentrations from 5 to 500 nM, and was not affected by episesamin, caffeic acid and ferulic acid in the same range of concentrations. The kinetic analysis indicated non-competitive type of inhibition by sesamin with Ki = 202 ± 18 nM. In conclusion, the results of our in vitro study revealed that sesamin was able to inhibit formation of a major metabolite of warfarin, 7-hydroxywarfarin. The potentially negative consequences of the consumption of high amounts of sesamin-containing food or dietary supplements in warfarin-treated patients need to be further studied.

Distribution characteristics and factors influencing oral warfarin adherence in patients after heart valve replacement

PURPOSE

Oral warfarin anticoagulation is a long-term treatment that is required after heart valve replacement. This treatment can prevent serious complications, such as embolism, thereby increasing patients' postoperative survival rates and quality of life. Patients treated with artificial mechanical heart valve replacement were followed up over the phone at different times after the procedure, which is an effective method for preventing accidents related to postoperative oral warfarin anticoagulation. Our goal was to determine a method for providing theoretical guidance to patients on oral warfarin anticoagulation following heart valve replacement.

PATIENTS AND METHODS

The participants of this study were patients who received artificial mechanical heart valve replacements and were followed up for 2 years after the procedure. Patient adherence to medical advice was calculated, and the distribution characteristics of adherence to prescribed timing, prescribed dose, and regular clinical follow-up among patients of both sexes and of different ages, regions, and educational levels attained were compared.

RESULTS

Univariate and multifactorial logistic regression analyses were used to evaluate the factors influencing adherence. Our analyses showed that adherence to oral warfarin anticoagulation in patients after heart valve replacement is influenced by sex, age, residential location, and educational attainment. The medication habits of patients can be evaluated accordingly via phone follow-up. As such, dose adjustment recommendations can be provided, significantly increasing the adherence to oral warfarin anticoagulation in patients after heart valve replacement.

CONCLUSION

Adherence to oral warfarin anticoagulation among patients after heart valve replacement is affected by sex, age, type of residence, and educational level, as well as adherence to clinical follow-up over the phone. The follow-up sessions help establish good doctor-patient communication, which is critical for timely medication guidance, thus shortening medication administration delays and decreasing the overall length of therapy.