Treatment of diarrhea caused by Giardia intestinalis and Entamoeba histolytica or E-dispar: A randomized, double-blind, placebo-controlled study of nitazoxanide

A prospective randomized, double-blind, placebo-controlled study was conduc ted to assess the efficacy and safety of nitazoxanide in the treatment of d iarrhea caused by Giardia intestinalis or Entamoeba histolytica and/or E. d ispar in 89 adults and adolescents, 22 of whom were diagnosed with G. intes tinalis, 53 with E. histolytica and/or E. dispar, and 14 with both G. intes tinalis and E. histolytica and/or E. dispar. The study medication was admin istered as 1 nitazoxanide 500-mg tablet or a matching placebo twice daily f or 3 days. Thirty-eight (81%) of 47 patients in the nitazoxanide treatment group resolved diarrhea within 7 days (median, 3 days) after initiation of treatment, versus 17 (40%) of 42 in the placebo group (P = .0002). With its efficacy in treating a broad spectrum of enteric protozoan pathogens, nita zoxanide could play an important role in the management of diarrhea caused by enteric protozoa, reducing morbidity and costs associated with these dia rrheal illnesses.