Spinal and cerebral hematoma in systemic lupus erythematosus and antiphospholipid syndrome: Is drug interaction the culprit?

Abstract

Thrombotic events are common in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). Warfarin is the most commonly used anticoagulant drug for thrombosis treatment, but it is can interact with many drugs, foods, or medicinal herbs. Herein, we presented a case with SLE and APS who was complicated by spinal and cerebral hematoma as a result of warfarin interaction. Spinal subdural hematoma and frontal intraparenchymal hematoma were occurred in our patient, who was in remission for 2 years with rituximab, hydroxychloroquine and warfarin. We learned that she had been using some herbal products (shepherd's purse and horsetail) and phenyramidol for a few days. Spinal and cerebral hematomas caused by the interaction of phenyramidol and warfarin were treated with fresh frozen plasma and vitamin K without the need for surgery. The drug interactions with warfarin can cause fatal hemorrhagic or thrombotic events. Especially, the patients with SLE and/or APS using warfarin should be warned not to use different medications or herbal agents.