Rapid oral desensitization for sulfonamides in patients with the acquired immunodeficiency syndrome

A prospective case series was undertaken in a university teaching hospital.

To evaluate the safety and efficacy of two oral desensitization procedures for sulfonamides in patients with the acquired immunodeficiency syndrome (AIDS).

A rapid oral desensitization protocol to sulfadiazine (2.5 hours) or trimethoprim-sulfamethoxazole (8 hours) was used. Increasing volumes of either drug were given orally every 15 minutes until 1 g of sulfadiazine or 1443.3 mg of trimethoprim-sulfamethoxazole was reached.

Nine of 13 (69%) patients were able to tolerate sulfadiazine for a period of 10 to 730 days (mean: 184 days). This was achieved in eight patients after the first attempt, in one after the second attempt. Five patients failed after the first attempts with or without premedications. Two of these five failed despite two attempts. Two patients relapsed 21 days after responding to rapid desensitization. Three patients underwent a successful 5 to 6-day slow desensitization protocol with premedications with high dose corticosteroids and antihistamines despite failures after two attempts with rapid desensitization in two of these patients and relapse in one.

Overall, 11 of 13 (85%) patients were successfully desensitized to sulfonamides using both rapid and slow methods. No life-threatening reactions occurred. Premedications with oral antihistamines and corticosteroids may be needed to control and prevent early occurrences of rash or pruritus during desensitization. In those who fail rapid desensitization, the slow method with premedications is an alternative.