Pharmacotherapy of disseminated histoplasmosis in patients with AIDS

Abstract

Objective: To review the pharmacotherapy of disseminated histoplasmosis (DH) in patients with AIDS. The article provides an overview of the pathophysiology, epidemiology, clinical presentation and diagnosis of this disease. Clinical trials reporting intervention with antifungal therapy are reviewed, with an emphasis on efficacy and toxicity of these agents.

Data sources: A MEDLINE search from 1976 to the present was performed to identify pertinent biomedical literature, including reviews.

Study selection: All available reviews and clinical trials in AIDS patients were evaluated, as were all available case series and interventional clinical trials.

Data synthesis: DH in patients with HIV infection is an AIDS-defining opportunistic infection caused by Histoplasma capsulatum. It is most frequently observed in HIV-infected patients living in or traveling to endemic regions. The clinical presentation most often includes fever and weight loss, but may be complicated by comorbid illness such as other opportunistic infections. Diagnosis is best established by histologic examination of peripheral blood smear or bone marrow aspirate, or isolation of the organism in cultures of blood, bone marrow, and respiratory secretions. Serologic examinations may provide supportive diagnostic information. Detection of histoplasma polysaccharide antigen (HPA) in serum or urine may prove to be a promising approach for the rapid diagnosis and therapeutic monitoring of DH in AIDS patients. In contrast to immunocompetent hosts, high relapse rates are reported after therapy in AIDS patients. Therefore, initial (induction) therapy is routinely followed by long-term (maintenance) therapy to prevent relapse. Issues regarding the selection, dosage, and duration of therapy, as well as prophylaxis of patients at highest risk, still need to be addressed by controlled clinical trials.

Conclusions: Amphotericin B is presently the drug of choice for induction therapy. Maintenance therapy with either amphotericin B or an oral azole antifungal agent active against H. capsulatum is necessary to prevent relapse. Itraconazole, a triazole antifungal agent, may provide effective alternative therapy for both induction and maintenance treatment of DH.