Treatment of giardiasis with tinidazole

Fifty-five patients, 51 males and 4 females heavily infected with Giardia lamblia were treated with a single 2 g dose of tinidazole (four tablets); 53 were cured. Of 20 other infected patients kept under the same conditions and given four placebo tablets, 18 continued to pass cysts or trophozoites in the stools during the whole 3- to 4-wk follow-up period in hospital. There were no side effects attributed to the drug.