What’s the most effective treatment for giardiasis?
Two RCTs found nitazoxanide to be effective (number needed to treat [NNT]=1.82) compared to placebo in adolescents and adults.6 A 3-day course of nitazoxanide was as effective as 5 days of metronidazole (80% vs 85%, P=0.61) in resolving clinical giardiasis.7
An RCT of albendazole, 400 mg for 5 days, in 28 adults found it to be as effective as 500 mg metronidazole given 3 times a day for 5 days (80% vs 83%) but less likely than metronidazole (2% vs 18%) to cause anorexia (number needed to harm [NNH]=6.25).
Recommendations
The Centers for Disease Control and Prevention recommends tinidazole, metronidazole, quinacrine, albendazole, or nitazoxanide to treat giardiasis; however, it doesn’t indicate a preference for 1 medicine over another.1 The Infectious Diseases Society of America has no guideline. The Sanford Guide to Antimicrobial Therapy recommends either a single 2-g dose of tinidazole or 500 mg of nitazoxanide PO bid for 3 days as primary treatment.8
Acknowledgments
The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Air Force Medical Service, nor the US Air Force.
