A Study of Itraconazole in the Treatment and Prevention of Histoplasmosis, a Fungal Infection, in Patients With AIDS

To evaluate the feasibility of itraconazole as (1) primary therapy in histoplasmosis and (2) maintenance therapy after completion of primary therapy. To evaluate the effect of therapy of CNS histoplasmosis. To determine if resistance to drug occurs in patients who fail therapy. Histoplasmosis is a serious opportunistic infection in patients with AIDS. Although the clinical response to amphotericin B treatment in the AIDS patients is generally good, administration difficulties and toxicity detract from its usefulness. Oral treatment with ketoconazole overcomes these limitations of amphotericin B, but does not appear to be effective for primary treatment in patients with AIDS. Itraconazole is a triazole compound in which preclinical studies have demonstrated activity against Histoplasmosis capsulatum. Preclinical studies have also shown that itraconazole appears effective in the treatment of histoplasmosis. The frequency of adverse reactions to itraconazole has been low in several studies. Central nervous system (CNS) involvement occurs in up to 20 percent of patients with histoplasmosis, and appears to have a poor response to amphotericin B treatment. Itraconazole has been used successfully in a small number of patients with cryptococcal meningitis, supporting a study of its use in CNS histoplasmosis. Histoplasmosis is a serious opportunistic infection in patients with AIDS. Although the clinical response to amphotericin B treatment in the AIDS patients is generally good, administration difficulties and toxicity detract from its usefulness. Oral treatment with ketoconazole overcomes these limitations of amphotericin B, but does not appear to be effective for primary treatment in patients with AIDS. Itraconazole is a triazole compound in which preclinical studies have demonstrated activity against Histoplasmosis capsulatum. Preclinical studies have also shown that itraconazole appears effective in the treatment of histoplasmosis. The frequency of adverse reactions to itraconazole has been low in several studies. Central nervous system (CNS) involvement occurs in up to 20 percent of patients with histoplasmosis, and appears to have a poor response to amphotericin B treatment. Itraconazole has been used successfully in a small number of patients with cryptococcal meningitis, supporting a study of its use in CNS histoplasmosis. At least 30 patients with AIDS and an initial episode of disseminated histoplasmosis are selected for this study. Up to 5 patients will have a diagnosis of CNS histoplasmosis. Therapy with all other systemic antifungal agents must be halted before study entry. Patients receive itraconazole for 3 days followed by daily oral doses for a total of 12 weeks. Patients who are doing well clinically, without evidence of clinical failure or dose-limiting toxicity, are permitted to continue maintenance therapy to prevent relapse at a reduced dose for an additional 12 months. Patients who are being treated for CNS histoplasmosis will continue to receive itraconazole.