title: Topiramate induced agranulocytosis.
abstract: A man in his 40s with a past history of neutropenia during zonisamide administration developed agranulocytosis 1 month after adding on topiramate to treat intractable partial epilepsy. His concurrent medication included phenytoin and acetazolamide. His white blood cell count recovered 5 days after discontinuation of topiramate. Topiramate is a sulfamate whose mechanism of antiepileptic activity is considered to include inhibition of carbonic anhydrase. Topiramate has a potential risk for haematopoietic adverse events; such events are rare and are related to immuno-allergic reaction or toxic effect of sulfonamides and sulfamates, including carbonic anhydrase inhibitors. Because this class of drugs is commonly used as an anti-glaucoma or diuretic agent, particular attention should be paid when initiating topiramate to a patient with a history of sulfonamide or sulfamate induced agranulocytosis, or when co-administrating topiramate with sulfonamides and sulfamates including carbonic anhydrase inhibitors.
authors.affiliation: Utano National Hospital, National Hospital Organization, Neurology, 8 Ondoyama-cho, Narutaki, Ukyoku, Kyoto, 616-8255, Japan.
authors.forename: Eiko Nakano
authors.initials: EN
authors.lastname: Minakawa
authors.forename: Riki
authors.initials: R
authors.lastname: Matsumoto
authors.forename: Masako
authors.initials: M
authors.lastname: Kinoshita