Enoxaparin-induced alopecia in patients with cerebral venous thrombosis

Abstract

Objective: To report three cases of alopecia induced by the anticoagulant enoxaparin in cerebral venous thrombosis (CVT) patients.

Case summary: Three female patients were treated initially with direct intrasinus urokinase, and then followed by low-molecular-weight heparin (LMWH) enoxaparin at 1 mg/kg given subcutaneously twice daily for 3 weeks. It was switched to oral anticoagulant warfarin at 5 mg daily for another 6 months. Nearly 3 weeks after the initiation of anticoagulation, all of the three patients complained of excessive hair loss with large areas of patchy, non-scarring alopecia. Hair growth returned to normal within 1 month after the completion of enoxaparin.

Discussion: Unfractionated heparin remains the first-line treatment of CVT because of its efficacy, safety and feasibility. Alopecia has been reported as a side effect of LMWHs dalteparin and tinzaparin. The pattern of hair loss, telogen effluvium, involves the induction of the hair follicle into a resting phase without apparent pathologic implication. In addition, this article also reviewed other medications taken by the patients that are possibly associated with hair loss.

Conclusion: From the review of literature, there is no report of alopecia caused by urokinase. Using the Naranjo ADR Probability Scale, a score of 6 suggests that enoxaparin was the probable cause of alopecia in our three patients. This report introduces evidence of alopecia as a probable side effect of enoxaparin, but stresses the efficacy and safety of LMWH. As this is not a life-threatening disorder, we hope to increase the awareness of pharmacists and clinicians to this relatively rare but important side effect.