Purpose: The effects of continuous or intermittent therapy with fluconazole on the recurrence of and the development of fluconazole resistance are not known.

Patients and Methods: We studied human immunodeficiency virus (HIV)-positive patients with CD₄ cell count <350 × 10⁶/L and oropharyngeal candidiasis in a prospective, randomized study. After initial treatment, 20 patients (16 of whom completed 3 months of follow-up) received continuous fluconazole at 200 mg/day, and 48 patients (28 of whom completed follow-up) received intermittent therapy at the time of symptomatic relapses. Oral samples were obtained weekly during episodes of infection and quarterly as surveillance cultures. Development of resistance was defined as a fourfold rise in minimum inhibitory concentration (MIC) to at least 16 μg/mL from the initial culture in the same species, the emergence of new, resistant (MIC ≥16 μg/mL) species, or a significant increase in the proportion of resistant isolates.

Results: During a mean follow-up of 11 months, median annual relapse rates were lower in patients on continuous therapy (0 episodes/year) than in patients on intermittent therapy (4.1 episodes/year; P <0.001). Sterile cultures were seen in 6 of 16 (38%) patients on continuous therapy compared with 3 of 28 (11%) on intermittent therapy (P = 0.04). Microbiological resistance developed in 9 of 16 (56%) patients on continuous treatment, compared with 13 of 28 (46%) on intermittent treatment (P = 0.75). However, despite isolates with increased MICs, 42 of 44 patients responded to fluconazole in doses up to 800 mg/day.

Conclusions: In patients with frequent recurrences, continuous suppressive therapy significantly reduced relapses and colonization. Resistance occurred with both continuous and intermittent therapy; however, therapeutic responses were excellent.