Antiplatelet drugs: a review of pharmacology and the perioperative management of patients in oral and maxillofacial surgery

Platelet FcγRIIA: An emerging regulator and biomarker in cardiovascular disease and cancer

Platelets, anucleate blood cells derive from megakaryocytes, are involved in cardiovascular diseases and tumors. FcγRIIA, the only FcγR expressed on human platelets, is known for its role in immune-related diseases. A growing body of evidence reveals that platelet FcγRIIA is a potential target for the prevention and control of cardiovascular disease and cancer, and is an advantageous biomarker. In this review, we describe the structure and physiological function of platelet FcγRIIA, its regulatory role in cardiovascular disease and cancer, and its potential clinical application.

Controversies in Stoppage of Antiplatelet and Anticoagulant Medications Prior to Oral Surgery

Dental procedures can pose a risk of bleeding, and it is not uncommon for dentists to consult prescribing physicians regarding a mutual patient's antiplatelet and anticoagulant medication to prevent excessive bleeding during or after an upcoming procedure. However, there has been a growing controversy in the dental community surrounding the stoppage of these medications prior to dental procedures. Some believe that stopping these medications prior to dental procedures is necessary to reduce the risk of bleeding complications, while others argue that stopping them can increase the risk of stroke or other thromboembolic events. The debate has left many dentists and specialists unsure about the best course of action when it comes to managing bleeding risk during dental procedures.In this article, we will review the antithrombotic medications, indications, mechanism of action, and its effects on the coagulation pathway, laboratory testing and reversal agents. Also, we will explore the controversy surrounding the stoppage of novel anitplatelets (eg,: prasurgrel and ticagrelor), dual-antiplatelets, triple-antiplatelet, vitamin K antagonists (eg,: wafarin, coumadin), and direct oral anticoagulants (eg,: dabigatran, rivaroxaban, xarelto and endoxaban) in dentistry and examine the current evidence and guidelines for managing dental patients undergoing oral surgery.

Perioperative Management of Antithrombotic Therapy in Patients Who Undergo Dental Procedures: A Systematic Review of the Literature and Network Meta-Analysis

BACKGROUND

The surgical dental treatment of subjects admitted for anticoagulants therapy represents a consistent risk for peri-operative bleeding. The aim of the present study was to investigate the clinical findings of dental surgery operative management of the patients under anticoagulants drugs protocol.

METHODS

The literature screening was performed using Pubmed/Medline, EMBASE and Cochrane library, considering only randomized clinical trials (RCTs) papers. No limitations about the publication's period, follow-up time or clinical parameters were considered.

RESULTS

A total of eight RCTs were included for the qualitative synthesis. No thromboembolic complications were reported in any studies. Several bleeding episodes associated with anticoagulant drugs in dental surgery were mild and generally happened on the first day after the treatment.

CONCLUSIONS

The use of local haemostatic measures is generally effective for bleeding control with no further pharmacological drug management or suspension.

Long-term outcomes after traumatic brain injury in elderly patients on antithrombotic therapy

INTRODUCTION

Elderly patients receiving antithrombotic treatment have a significantly higher risk of developing an intracranial hemorrhage when suffering traumatic brain injury (TBI), potentially contributing to higher mortality rates and worse functional outcomes. It is unclear whether different antithrombotic drugs carry a similar risk.

OBJECTIVE

This study aims to investigate injury patterns and long-term outcomes after TBI in elderly patients treated with antithrombotic drugs.

METHODS

The clinical records of 2999 patients ≥ 65 years old admitted to the University Hospitals Leuven (Belgium) between 1999 and 2019 with a diagnosis of TBI, spanning all injury severities, were manually screened.

RESULTS

A total of 1443 patients who had not experienced a cerebrovascular accident prior to TBI nor presented with a chronic subdural hematoma at admission were included in the analysis. Relevant clinical information, including medication use and coagulation lab tests, was manually registered and statistically analyzed using Python and R. In the overall cohort, 418 (29.0%) of the patients were treated with acetylsalicylic acid before TBI, 58 (4.0%) with vitamin K antagonists (VKA), 14 (1.0%) with a different antithrombotic drug, and 953 (66.0%) did not receive any antithrombotic treatment. The median age was 81 years (IQR = 11). The most common cause of TBI was a fall accident (79.4% of the cases), and 35.7% of the cases were classified as mild TBI. Patients treated with vitamin K antagonists had the highest rate of subdural hematomas (44.8%) (p = 0.02), hospitalization (98.3%, p = 0.03), intensive care unit admissions (41.4%, p < 0.01), and mortality within 30 days post-TBI (22.4%, p < 0.01). The number of patients treated with adenosine diphosphate (ADP) receptor antagonists and direct oral anticoagulants (DOACs) was too low to draw conclusions about the risks associated with these antithrombotic drugs.

CONCLUSION

In a large cohort of elderly patients, treatment with VKA prior to TBI was associated with a higher rate of acute subdural hematoma and a worse outcome, compared with other patients. However, intake of low dose aspirin prior to TBI did not have such effects. Therefore, the choice of antithrombotic treatment in elderly patients is of utmost importance with respect to risks associated with TBI, and patients should be counselled accordingly. Future studies will determine whether the shift towards DOACs is mitigating the poor outcomes associated with VKA after TBI.

Bleeding disorders in implant dentistry: a narrative review and a treatment guide

Purpose

Considering a high prevalence of congenital and especially acquired bleeding disorders, their heterogeneity and the multitude of possible treatments strategies, a review of the scientific data on this topic is needed to implement a treatment guide for healthcare professionals.

Methods

A selective literature review was performed via PubMed for articles describing oral surgery / dental implant procedures in patients with congenital and acquired bleeding disorders. Out of the existing literature, potential treatment algorithms were extrapolated.

Results

In order to assess the susceptibility to bleeding, risk stratification can be used for both congenital and acquired coagulation disorders. This risk stratification, together with an appropriate therapeutic pathway, allows for an adequate and individualized therapy for each patient. A central point is the close interdisciplinary cooperation with specialists. In addition to the discontinuation or replacement of existing treatment modalities, local hemostyptic measures are of primary importance. If local measures are not sufficient, systemically administered substances such as desmopressin and blood products have to be used.

Conclusions

Despite the limited evidence, a treatment guide could be developed by means of this narrative review to improve safety for patients and practitioners. Prospective randomized controlled trials are needed to allow the implementation of official evidence-based guidelines.

Study on the Interaction between Deuterium Clopidogrel and Omeprazole

<b><i>Introduction:</i></b> Dual antiplatelet therapy with aspirin in combination with a P2Y₁₂ receptor antagonist is a cornerstone for treating patients with acute coronary syndrome and in percutaneous coronary intervention. However, as this combination of antiplatelet therapy increases the risk of bleeding, proton pump inhibitors (PPIs) are currently recommended to prevent gastrointestinal ulcers and bleeding. The cytochrome P450 (CYP450) isoenzyme system metabolizes both clopidogrel (CLP) and PPIs. Unfortunately, omeprazole (OM) reduce the antiplatelet activity of CLP and increases the probability of recurrence of cardiovascular events by competitively inhibiting the CYP450 isoenzyme CYP2C19. <b><i>Methods:</i></b> To address these abovementioned problems, we designed and synthesized deuterium CLP (D-CL) using selective deuterium technology. Our previous research results showed that D-CL had better pharmacokinetic and pharmacodynamic properties. Thus, the HPLC-MS/MS method, cocktail method, Born method, electro-stimulated thrombus generation, and thrombus elastography were used to detect the production of thiol active metabolites (AM), CYP450 enzyme activities, platelet aggregation, time and length of thrombus formation, and the maximum clot strength after combination therapy. We investigated the pharmacokinetics and pharmacodynamics properties of D-CL combined with OM. <b><i>Results:</i></b> As compared to CLP, D-CL was less affected when combined with OM, which was reflected in lower inhibitory effects of CYP450 enzyme activities, a greater area under the curve of AM, and better antiplatelet and antithrombotic effects. <b><i>Conclusion:</i></b> D-CL may reduce drug-drug interactions and address the clinical disadvantages of CLP.

Flavonoids: Antiplatelet Effect as Inhibitors of COX-1

Flavonoids are compounds with a benzopyranic structure that exhibits multiple pharmacological activities. They are known for their venotonic activity, but their mechanism of action remains unclear. It is thought that, as this mechanism is mediated by prostaglandins, these compounds may interfere with the arachidonic acid (AA) cascade. These assays are designed to measure the antiplatelet aggregation capacity of quercetin, rutin, diosmetin, diosmin, and hidrosmin, as well as to evaluate a potential structure−activity ratio. In this paper, several studies on platelet aggregation at different concentrations (from 0.33 mM to 1.5 mM) of different flavone compounds are conducted, measuring platelet aggregation by impedance aggregometry, and the cyclooxygenase (COX) activity by metabolites generated, including the activity of the pure recombinant enzyme in the presence of these polyphenols. The results obtained showed that quercetin and diosmetin aglycones have a greater antiplatelet effect and inhibit the COX enzyme activity to a greater extent than their heterosides; however, the fact that greater inhibition of the pure recombinant enzyme was achieved by heterosides suggests that these compounds may have difficulty in crossing biological membranes. In any case, in view of the results obtained, it can be concluded that flavonoids could be useful as coadjuvants in the treatment of cardiovascular pathologies.

Knowledge and Practice of Dentists Managing Patients on Antithrombotic Medications: A Cross-Sectional Survey

OBJECTIVES

 In this article, we explored the level of knowledge and practice of licensed dentists in the United Arab Emirates regarding managing patients on antithrombotic medications. Moreover, to assess the need for educational intervention in this area is one of the objectives.

MATERIALS AND METHODS

 A total of 502 dentists answered 22 close-ended questionnaires. The sample size was determined based on the registry of the Ministry of Health.

RESULTS

 Only 5.6 and 5.9% showed satisfactory overall awareness about aspirin and plavix, respectively, as drugs may hamper hemostasis. A substantial proportion of dentists consider aspirin (63.1%) and clopidogrel (52.2%) discontinuation before treatment. More than one-third of the participants shall not consider extracting teeth before physician approval, and one-quarter to one-third of them refer patients on such medications to oral surgeons to perform tooth extraction. Most respondents did not adequately answer the questions about the additional hemostatic measures and postoperative analgesia. A significantly high number of participants (n = 440, 87.6%) want to attend updated courses on the dental management of such patients.

CONCLUSIONS

 The dentists demonstrate a contrasting diversity of knowledge and practice approaches to patient management on antiplatelet agents. There is an apparent demand to raise understanding of the evidence-based management of a patient on such medications. It is vital to keep formalized training sessions and provide the necessary expertise to students and dentists to prevent unwanted complications.

Perioperative Antiplatelet and Anticoagulant Management with Endodontic Microsurgical Techniques

INTRODUCTION

The purpose of this study was to review evidence-based recommendations for the safe perioperative management of patients undergoing endodontic microsurgery who are currently taking antiplatelet or anticoagulant medications. Using the PICO (Population, Intervention, Comparison, Outcome) format, the following scientific question was asked: In patients taking anticoagulant or antiplatelet agents, what is the available evidence in the management of endodontic microsurgery?

METHODS

MEDLINE, Scopus, Cochrane Library, and ClinicalTrials.gov databases were searched to identify current recommendations regarding the management of antiplatelet and anticoagulant medications in the context of outpatient dental surgical procedures. Additionally, the authors hand searched the bibliographies of all relevant articles, the gray literature, and textbooks. Because of the lack of clinical studies and evidence on this subject, articles and guidelines from other organizations and association position statements were included.

RESULTS

Because any minor surgery can become a major surgery, the treating doctor needs to best assess the risk of bleeding, especially if the surgery is anticipated to take longer than 45 minutes. Every patient should be stratified on a case-by-case basis. Consultation with the patient's physician is highly recommended.

CONCLUSIONS

In order to maximize the effects of these medications (to prevent thrombosis) while minimizing the potential risks (procedural hemorrhage), clinicians should be aware of the best available evidence when considering continuation or discontinuation of antiplatelet and anticoagulant agents perioperatively for endodontic microsurgery. Ideally, a joint effort from an expert panel for microsurgery would be warranted.