Two-day oral desensitization to trimethoprim-sulfamethoxazole in HIV-infected patients.

OBJECTIVE: To establish whether an outpatient, 2-day oral desensitization protocol would be both safe and effective in HIV-infected patients with previous trimethoprim-sulfamethoxazole (TMP-SMX) intolerance.

DESIGN: A single center trial of TMP-SMX desensitization in HIV-infected patients with prior TMP-SMX hypersensitivity reactions.

METHODS: HIV-infected patients with CD4 lymphocyte counts < 250 x 10(6)/l cells or CD4% < 20% with previous non-life-threatening hypersensitivity reactions to TMP-SMX were eligible. The desensitization protocol utilized 40 graduated doses over 36 h; the first 28 doses (7.5 h) of the protocol were given in an outpatient clinic with the remaining doses taken at home.

RESULTS: Twenty-seven (60%) of the 45 subjects completed the protocol and were subsequently maintained on daily TMP-SMX without adverse reactions (mean follow-up, 9 months; range, 4-16 months). Patients with CD4 counts < 100 x 10(6)/l cells were just as likely as patients with higher CD4 counts to tolerate the desensitization. No patient required hospitalization for treatment of an adverse reaction.

CONCLUSION: Oral desensitization to TMP-SMX in HIV-infected patients is a useful option in the management of patients with advanced HIV disease and prior intolerance to TMP-SMX.