Massive intentional enoxaparin overdose managed with minimal protamine: A single case report

Abstract

Abstract Purpose The case of a patient with a massive acute enoxaparin overdose managed with observation and minimal doses of protamine sulfate is reported. Summary Acute enoxaparin overdoses are uncommonly reported and management is widely variable. A 25-year-old man presented to the emergency department (ED) shortly after reporting that he had attempted suicide by injecting himself with 31 syringes of 80 mg of enoxaparin (a total of 2,480 mg) in the abdomen and other areas of his body. The patient also had self-inflicted superficial lacerations of the forearm. Due to concern over suspected compartment syndrome in the forearm, 25 mg of protamine was administered. Approximately 11 hours after reported enoxaparin self-injection, the patient’s activated partial thromboplastin time (aPTT) was 206 seconds, prompting administration of an additional 50 mg of protamine. Three hours later, the aPTT had decreased to 79 seconds, then rose over several hours to 127 seconds before gradually declining to normal values. Protamine administration had no appreciable impact on anti–factor Xa activity. The patient did not require any blood products during the hospital admission. There were no further complications, and the patient was discharged to the inpatient psychiatry service on hospital day 8. Conclusion The case highlights the role of protamine as a reversal agent in the management of low-molecular-weight heparin overdoses. The optimal dosing and efficacy of protamine for this indication needs further investigation.