Abstracts

RATIONALE: The package insert for zonegran (ZNS) states: [dsquote]Zonegran is contraindicated in patients who have demonstrated hypersensitivity to sulfonamides or zonegran[dsquote] However, no direct evidence is available to support this statement. Because ZNS is structurally stereospecifically different for sulfonamide antibiotics the cross-reactivity is not known. The objective of this report is to review our experience with patients who have a history of hypersensitivity to sulfonamides and were treated with zonisamide.
METHODS: All patients seen at the Minnesota Epilepsy Group are asked to report any allergies. The type of allergic action is then clarified (e.g., rash, urticaria, angioedema, etc). Fifteen adults and children who reported [dsquote]sulfa[dsquote] allergy as a rash, had also been treated with ZNS. The allergic reaction to sulfonamide antibiotic was investigated through review of medical records and patient contact, for validation. Charts were reviewed for cross hypersensitivity reactions.
RESULTS: Despite the report of rash caused by sulfonamide antibiotics in all 15 patients, in only eight could we find good supportive evidence to validate this reaction. There were 4 males, 4 females ages 9-78-years old. Median age was 25-years. No rash or allergic reaction of any type occurred in these eight patients. Seven patients continue treatment with zonisamide with benefit. One discontinued after 3-months due to lack of improvement in seizure control. No hypersensitivity reaction to ZNS was seen in any of the 15 patients reporting rash.
CONCLUSIONS: These numbers are small, but the stereospecific structure of ZNS is different from that of sulfonamide antibiotics. This may decrease the risk for hypersensitivity and cross-reaction. Patients with intractable epilepsy and a history of rash from [dsquote]sulfa[dsquote] drugs may benefit from a cautious trial of ZNS.
(Disclosure: Honoraria - Yes.)