Amphotericin B and flucytosine in the treatment of candidal cystitis

The causes, diagnosis, and treatment of candidal cystitis are reviewed. It is necessary to differentiate between colonization and infection because Candida organisms reside normally in the digestive tract of humans and do not normally exist in the urine. A diagnosis of candidal cystitis is based on a urine sample culture growth of more than 10,000 colonies/ml. Initial treatment involves removing as many of the precipitating factors as possible. The current treatment of choice is irrigation of the bladder with amphotericin B. Continuous irrigation with a three-way catheter is recommended over intermittent instillations. Oral flucytosine can be added to exert synergistic action in persistent infections, or when renal infection is suspected, or if catheterization is not desirable. The major problem with flucytosine is that many strains of Candida are initially resistant, and some strains develop secondary resistance during the course of therapy. Because of its potential for toxicity, intravenous amphotericin B is reserved for systemic infections and for those infections refractory to more conservative therapy.