Central nervous system toxoplasmosis in AIDS patients: efficacy of an intermittent maintenance therapy.

Fifty-five episodes of central nervous system (CNS) toxoplasmosis developing in 43 of the 329 AIDS cases seen at our institution were diagnosed during a 34-month period and were prospectively studied. Acute episodes were treated with a pyrimethamine/sulfadiazine (P/S) combination for a mean of 21 days. Because of a previously known major allergy to sulfonamides, three episodes were treated with clindamycin instead of sulphadiazine. In those patients who accepted maintenance therapy, a combination of P/S or pyrimethamine and clindamycin (P/C) was administered 2 days per week. Thirty-six patients (83.7%) survived the first episode. Four of these 36 were lost to further study. Six of the 12 (50%) who decided not to undergo maintenance therapy relapsed (mean follow-up: 12 months). Fourteen patients were given P/S and none relapsed while they were on maintenance therapy (mean follow-up: 10.3 months). Six patients received an intermittent maintenance treatment with P/C and one relapsed 2 months after starting the maintenance therapy (mean follow-up: 13.7 months). We conclude that an intermittent (2 days per week) maintenance treatment for CNS toxoplasmosis with P/S was effective in preventing relapses, although prospective randomized studies remain to be done.