Bleeding the system: a case of feigned enoxaparin overdose

BACKGROUND

Low-molecular-weight heparins (LMWHs) have become ubiquitously used as anticoagulants because of their comparative safety and ease of use; however they may be fatal if taken in overdose, and lack of familiarity with their pharmacology may hinder appropriate care.

OBJECTIVE

The author reports a case of feigned LMWH overdose so as to alert practitioners to this diagnostic possibility.

METHOD

This is a case report of a 49-year-old homeless man who reported a deliberate overdose of an injectable LMWH. The author reviews the mechanism of action and monitoring of LMWHs.

RESULTS

On the basis of his unusual presentation and previously documented history and medical work-up, he was ultimately diagnosed with malingering.

DISCUSSION

Feigned LMWH overdose is ideally suited to the purposes of malingering, since it represents a medical emergency that requires inpatient medical hospitalization and testing at outside laboratory facilities to verify the overdose.

Incomplete Reversal of Enoxaparin Toxicity by Protamine: Implications of Renal Insufficiency, Obesity, and Low Molecular Weight Heparin Sulfate Content

The use of low molecular weight heparin (LMWH) is increasing throughout North America and Europe for a number of reasons: 1). ease of use; 2). predictable dose response; 3). less heparin associated thrombocytopenia. However, aside from increased costs, LMWH has significant potential drawbacks: 1). poor reversibility; 2). tendency to accumulate in renal insufficiency; 3). less experience in subset patient groups such as morbid obesity. We report a case of a postoperative morbidly obese patient who developed enoxaparin toxicity secondary to acute renal failure that did not reverse with protamine sulfate infusion. In addition, we review the use of LMWH in renal insufficiency, dosing in obese patients,and the importance of sulfate content in the efficacy of protamine sulfate as a reversing agent for LMWH.