Enoxaparin-induced alopecia in patients with cerebral venous thrombosis

Abstract

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