Treatments and drugs
By Mayo Clinic staffChildren and adults who have giardia infection but no symptoms usually don't need treatment unless they're likely to spread the parasites. Many people who do have problems often get better on their own in a few weeks.
When signs and symptoms are severe or the infection persists, doctors usually treat giardiasis with medications such as:
- Metronidazole (Flagyl). Metronidazole is the most commonly used antibiotic for giardia infection. Side effects may include nausea and a metallic taste in the mouth. Don't drink alcohol while taking this medication.
- Tinidazole (Tindamax). Tinidazole works as well as metronidazole and has many of the same side effects, but it can be given in a single dose.
- Nitazoxanide (Alinia). Because it comes in a liquid form, nitazoxanide may be easier for children to swallow.
- Paromomycin. Although paromomycin is less effective than other treatments, it also is less likely to cause birth defects during pregnancy.
- Fact sheet: Giardia infection (giardiasis). Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dpd/parasites/giardiasis/factsht_giardia.htm. Accessed March 17, 2010.
- Pickering LK. Giardia lamblia (giardiasis). In: Long SS, et al. Principles and Practice of Pediatric Infectious Diseases. 3rd ed. Philadelphia, Pa.: Churchill Livingston Elsevier; 2008. http://www.mdconsult.com/das/book/body/189644263-3/969360504/1679/269.html#4-u1.0-B978-0-443-06687-0..50268-X_4686. Accessed March 17, 2010.
- Huston CD. Giardia lamblia. In: Feldman M, et al. Sleisenger & Fordran's Gastrointestinal and Liver Disease. 8th ed. Philadelphia, Pa.: Saunders Elsevier; 2006. http://www.mdconsult.com/das/book/body/189644263-3/969360504/1389/793.html#4-u1.0-B1-4160-0245-6..50111-6--cesec14_5019. Accessed March 17, 2010.
- Leder K, et al. Patient information: Giardia. http://www.uptodate.com/home/index.html. Accessed March 17, 2010.
- Rohren CH (expert opinion). Mayo Clinic, Rochester, Minn. April 1, 2010.
- Munoz FM. Treatment and prevention of giardiasis in children. http://www.uptodate.com/home/index.html. Accessed March 17, 2010.

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