5-Fluorocytosine in the Treatment of Cryptococcal and Candida Mycoses

Abstract

Five patients with systemic mycoses were treated with oral 5-fluorocytosine for 22 to 820 days. Two patients with chronic cryptococcal meningitis had become unresponsive to amphotericin B therapy; both improved dramatically with the concomitant administration of 5-fluorocytosine but subsequently relapsed. A third patient had cryptococcal meningitis and a pulmonary nodule; the meningitis was cured with amphotericin B, but the pulmonary infection was active 1 year later and responded to 5-fluorocytosine. A fourth patient with cryptococcal meningitis survived only briefly but showed evidence of improvement before death. A single patient with candida endocarditis on a Starr-Edwards aortic prosthesis responded favorably to combined therapy with amphotericin B, 5-fluorocytosine, and surgical replacement of the prosthesis. Although cure rates could not be calculated, therapy with 5-fluorocytosine was well tolerated and significantly efficacious in the treatment of complicated mycoses to merit further clinical evaluation. The major limiting factor in its usefulness for treating cryptococcal disease may be the in vivo development of resistance during therapy.