How is giardiasis treated?
The most common treatment for giardiasis is metronidazole (Flagyl) for 5-10 days. It eradicates the Giardia more than 85% of the time, but it often causes gastrointestinal side effects such as nausea and a metallic taste as well as dizziness and headache. Despite its effectiveness, metronidazole is not approved by the FDA in the US for treatment of giardiasis. The only drug approved for treating giardiasis in the U.S. is furazolidone (Furoxone) for 7-10 days. It is approximately as effective as metronidazole. Tinidazole is available outside the U.S. and is highly effective at treating giardiasis(>90%). It also can be given as a single dose and is well tolerated. Quinacrine is very effective for treating giardiasis but is no longer available in the U.S. Paromomycin and albendazole, though effective, are less effective than other treatments. Occasionally, treatment fails to eradicate Giardia. In such cases, the drug may be changed or a longer duration or higher dose may be used. Combinat