RESUMO
Giardia intestinalis is the most common intestinal protozoan in the under developed countries. Treatment of infection has some difficulties by metronidazole because of long course of therapy and various side effects. The objective of this study was to determine efficacy and side effects of tinidazole compared with metronidazole in the treatment of giardiasis in children. A randomized controlled clinical trial, 106 subjects [69 males, 37 females] with Giardia intestinalis infection admitted to out patients or private clinics in Hamdan, West of Iran, was treated with tinidazole or metronidazole. The study period was May 2002 to January 2003. Tinidazole 50 mg/kg single dose and metronidazole 15 mg/kg three times a day for seven days were given orally to children. Parasitological cure was documented when there was 3 times negative stool examination for giardiasis at 1-2 weeks after therapy. Thirty-seven of 42 individuals [88.1%] treated with tinidazole and 43 of 64 children [67.2%] treated with metronidazole had parasitological cure. Cure rates between two groups were significant statistically [P<0.01]. No major side effect were observed except two cases in metronidazole group who had mild headache and abdominal pain for two days and some had metallic taste. Three cases in tinidazole group had nausea, dizziness and headache. Tinidazole was more effective than metronidazole, produced fewer and mild side effects and is recommended as drug of choice in single dose therapy for giardiasis. Because of single dose administration, short course of therapy and good compliance of patients, this preparation is preferred to metronidazole in the treatment of giardiasis