Treatment of Giardiasis.

Tinidazole is the first-line drug treatment of giardiasis, as it requires only a single dose to cure infection in most individuals. The related drug metronidazole is as effective, but it requires 5 to 7 days of three times a day therapy. Nitazoxanide appears in limited studies to be as effective as tinidazole or metronidazole, and it does not have the bitter taste of nitroimidazoles. A good alternate for use during pregnancy is paromomycin. Cure of infection varies between 60% and 100% with one course of treatment. Less effective and/or less well-tolerated drugs for the treatment of giardiasis include albendazole, quinacrine, and furazolidone; the use of these agents should be reserved for giardiasis refractory to treatment with the first-line agents.