Editorial [Abnormal Bleeding or Bruising Associated with Antiepileptic Treatment]

In this issue of Current Drug Safety, there is a single case report of topiramate-induced epistaxis in a 36 year old woman who was being treated for migraine [1]. The dose was increased gradually to 100 mg over one month. 35 days after starting the topiramate and five days after having been on the dose of 100 mg she had repeated prolonged epistaxis. The epistaxis resolved within 12 hours of discontinuing the topiramate. Page et al. [2] previously reported a 61 year old woman treated with topiramate 25 mg daily for lower limb neuropathy. Seven days after starting treatment she had severe epistaxis lasting 8 days, requiring emergency treatment. The epistaxis resolved one week after the topiramate was stopped. Three months later the topiramate was recommenced and she again developed intractable epistaxis. She was treated with two units of packed red cells. One week after stopping the topiramate, for a second time, the epistaxis stopped. She had no subsequent recurrence. No other cases could be located in the literature, although Page et al. have pointed out that epistaxis was reported on 1-4% of patients receiving topiramate in clinical trials. It has been suggested that topiramate might affect platelet function through modulation of L type calcium ion channels.