infectious diseases
Giardiasis
Treatment of Giardiasis
Tinidazole,metronidazole, ornitazoxanide For symptomatic giardiasis,tinidazole,metronidazole, ornitazoxanideare used. Treatment failures and resistance can occur with any of them. Tinidazoleis as effective asmetronidazole, buttinidazoleis better tolerated and administered as a single dose as follows: Adults: 2 g orally once Children: 50 mg/kg [maximum 2 g] orally once Metronidazoleis given as follows: Adults: 250 mg orally 3 times a day for 5 to 7 days Children: 5 mg/kg orally 3 times a day for 5 to 7 days Adverse effects ofmetronidazoleinclude nausea and headaches.Metronidazoleandtinidazoleshould not be given to pregnant women. Alcohol must be avoided because these drugs have adisulfiram-like effect. In terms of gastrointestinal adverse effects,tinidazoleis generally better tolerated thanmetronidazole. Nitazoxanideis given orally for 3 days as follows: Age 1 to 3 years: 100 mg 2 times a day Age 4 to 11 years: 200 mg 2 times a day Age > 12 years (including adults): 500 mg 2 times a day Nitazoxanideis available in liquid form for children. The safety ofnitazoxanideduring pregnancy has not been assessed. If therapy cannot be delayed because of symptoms, the nonabsorbable aminoglycosideparomomycin(8 to 11 mg/kg orally 3 times a day for 5 to 10 days) is an option if the benefit outweighs the risk. Furazolidone, quinacrine, oralbendazoleare rarely used because of potential toxicity, lower efficacy, or cost. Even after parasitologic cure, patients may experience lactose intolerance, Irritable Bowel Syndrome (IBS) , or fatigue. 