Evaluation of dabigatran exposures reported to poison control centers

Direct oral anticoagulants toxicity in children: an overview and practical guide

INTRODUCTION

By increasing use of direct oral anticoagulants (DOACs) in adults and children, gradual increase in the number of intentional or unintentional DOAC poisonings among children is suspected in the near future. Hence, clinicians and pharmacists need to be familiar with the clinical features and management of DOAC-toxicity among pediatric population.

AREAS COVERED

This article provides an overview and practical guide to DOAC-toxicity in pediatrics according to the available clinical evidence.

EXPERT OPINION

Based on limited available data, accidental pediatric ingestion of DOACs can be managed by supportive care in most cases. However, serious toxicity may occur following massive overdose, in presence of underlying disorders (renal or hepatic dysfunction) and concurrent anticoagulant therapy. Activated charcoal is recommended for known recent ingestion of DOACs (within 2-4 hours) to reduce the gastrointestinal absorption. Supportive interventions including local hemostatic measures and volume resuscitation are the cornerstone of management of bleeding. Vitamin K and fresh frozen plasma are ineffective for DOAC reversal and thus are not recommended. Currently, safety and efficacy data regarding the use of specific reversal agents (including idarucizumab and andexanet alfa) and 3-factor or 4-factor prothrombin complex concentrate (PCC) or activated PCC (aPCC) among children with DOAC-associated bleeding are lacking.

Antithrombotic and Antiplatelet Drug Toxicity

Anticoagulant and antiplatelet drugs target a specific portion of the coagulation cascade or the platelet activation and aggregation pathway. The primary toxicity associated with these agents is hemorrhage. Understanding the pharmacology of these drugs allows the treating clinician to choose the correct antidotal therapy. Reversal agents exist for some of these drugs; however, not all have proven patient-centered outcomes. The anticoagulants covered in this review are vitamin K antagonists, heparins, fondaparinux, hirudin derivatives, argatroban, oral factor Xa antagonists, and dabigatran. The antiplatelet agents reviewed are aspirin, adenosine diphosphate antagonists, dipyridamole, and glycoprotein IIb/IIIa antagonists. Additional notable toxicities are also reviewed.

Exploratory Ingestions of Novel Anticoagulants and Antiplatelets: What Is the Risk?

BACKGROUND

Historically, anticoagulants and antiplatelet agents included warfarin and aspirin, respectively. In recent years, numerous novel anticoagulants (eg, direct thrombin inhibitors and factor Xa inhibitors) as well as the adenosine diphosphate receptor antagonists have increased significantly. Little information on the bleeding risk after exploratory ingestion of these agents is available. The primary purpose of this study is to evaluate the bleeding risk of these agents after an exploratory ingestion in children 6 years or younger.

METHODS

This retrospective multicenter poison control center study was conducted on calls between 2005 and 2014. The following agents were included: apixaban, clopidogrel, dabigatran, edoxaban, prasugrel, rivaroxaban, or ticagrelor. Bleeding characteristics and treatment rendered were recorded.

RESULTS

A total of 638 cases were identified. Most cases involved antiplatelet agents. No patient developed any bleeding complication. The administration of charcoal was independent of the amount of drug ingested.

CONCLUSION

Accidental, exploratory ingestions of these agents seem well tolerated, with no patient developing bleeding complications.

Assessing Bleeding Risk in Patients With Intentional Overdoses of Novel Antiplatelet and Anticoagulant Medications

STUDY OBJECTIVE

In recent years, the use of novel anticoagulants and antiplatelet agents has become widespread. Little is known about the toxicity and bleeding risk of these agents after acute overdose. The primary objective of this study is to evaluate the relative risk of all bleeding and major bleeding in patients with acute overdose of novel antiplatelet and anticoagulant medications.

METHODS

This study is a retrospective study of acute ingestion of apixaban, clopidogrel, ticlopidine, dabigatran, edoxaban, prasugrel, rivaroxaban, and ticagrelor reported to 7 poison control centers in 4 states during a 10-year span. The prevalence of bleeding for each agent was calculated, and hemorrhage was classified as trivial, minor, or major.

RESULTS

A total of 322 acute overdoses were identified, with the majority of cases involving clopidogrel (260; 80.7%). Hemorrhage occurred in 16 cases (4.9%), including 7 cases of clopidogrel, 6 cases of rivaroxaban, 2 cases of dabigatran, and 1 case of apixaban. Most cases of hemorrhage were classified as major (n=9). Comparing the novel anticoagulants with the P2Y12 receptor inhibitors, the relative risk for any bleeding with novel anticoagulant was 6.68 (95% confidence interval 2.63 to 17.1); the relative risk of major bleeding was 18.1 (95% confidence interval 3.85 to 85.0).

CONCLUSION

Acute overdose of novel anticoagulants or antiplatelet agents is associated with a small risk of significant hemorrhage. The risk is greater with the factor Xa inhibitors and direct thrombin inhibitors than with the P2Y12 receptor antagonists.

Management of Patients on Non-Vitamin K Antagonist Oral Anticoagulants in the Acute Care and Periprocedural Setting: A Scientific Statement From the American Heart Association

Non-vitamin K oral anticoagulants (NOACs) are now widely used as alternatives to warfarin for stroke prevention in atrial fibrillation and management of venous thromboembolism. In clinical practice, there is still widespread uncertainty on how to manage patients on NOACs who bleed or who are at risk for bleeding. Clinical trial data related to NOAC reversal for bleeding and perioperative management are sparse, and recommendations are largely derived from expert opinion. Knowledge of time of last ingestion of the NOAC and renal function is critical to managing these patients given that laboratory measurement is challenging because of the lack of commercially available assays in the United States. Idarucizumab is available as an antidote to rapidly reverse the effects of dabigatran. At present, there is no specific antidote available in the United States for the oral factor Xa inhibitors. Prothrombin concentrate may be considered in life-threatening bleeding. Healthcare institutions should adopt a NOAC reversal and perioperative management protocol developed with multidisciplinary input.

Steps to diagnosis of a case of surreptitious intake of one of the newer direct oral anticoagulants: a case report and literature review

Little is known about the effects of newer oral anticoagulants on various coagulation factors. When presented with a case of intentional or suspected overdose with an abnormal coagulation profile, it is imperative to have a working diagnostic algorithm to narrow the cause to a specific drug or drug class. This may become more crucial and time sensitive when dealing with a case of acute hemorrhage. Here we discuss the first reported case of what appears to be a surreptitious intake of newer oral anticoagulants and the steps leading to the diagnosis.

What is the role of hemodialysis for dabigatran-associated major bleeding?

A 70-year-old male with a history of atrial fibrillation who is being anticoagulated with dabigatran etexilate presents to the emergency room with melena. He reports taking his most recent dose of dabigatran more than 2 hours ago. On examination, he is hypotensive and tachycardic, and he continues to have melanotic stools. Laboratory testing reveals a calculated creatinine clearance of 15 mL/min, a prothrombin time of 16.5 seconds (reference range: 11.8-15.2 seconds), an international normalized ratio of 1.2 (reference range: 0.9-1.2), and an activated partial thromboplastin time of 50 seconds (reference range: 22.2-33.0 seconds). You are asked by the emergency medicine physician whether hemodialysis should be considered to decrease the patient's plasma dabigatran level.