Treatment of asymptomatic amebiasis in homosexual men. Clinical trials with metronidazole, tinidazole, and diloxanide furoate.

In a randomized trial, the authors treated 42 asymptomatic homosexual men who had Entamoeba histolytica in fecal specimens with either metronidazole or tinidazole (study 1). They treated both groups initially with 2,000 mg in a single dose, and in case of failure with 2,000 mg daily for 5 days. In cases of repeated failure, the authors prescribed a dosage of 500 mg of diloxanide furoate three times per day (TID) for 10 days. In a subsequent study (study 2) the authors treated 49 asymptomatic homosexual men who had E. histolytica in fecal specimens with 500 mg of diloxanide furoate TID for 10 days. In study 1, the parasitological cure rates (PCR) for metronidazole and tinidazole were 29%-56%. Among the men treated with diloxanide furoate, the PCR was 93%. In study 2 the PCR with diloxanide furoate was 88%, which was significantly better (P less than .05) than metronidazole/tinidazole treatment in study 1. The present studies show that diloxanide furoate is an effective treatment of amebiasis in asymptomatic patients.