Treatment

The clinical significance of Blastocystis spp. is controversial.

Treatment with metronidazole* at various doses has been reported, for example (adults):

• 250 mg to 750 mg metronidazole* orally 3 times daily for 10 days
• 1500 mg metronidazole* orally once daily for 10 days

Note: Lack of response to metronidazole has been noted in some areas (Yakoob et al., Br J Biomed Sci 2004;61:75).

Treatment with trimethoprim (TMP)*/sulfamethoxazole (SMX)* at various doses has been reported, for example (adults):

• 6 mg/kg TMP*, 30 mg/kg SMX* once daily for 7 days
• 320mg TMP*, 1600 mg SMX* once daily for 7 days
• 160 mg TMP*, 800 mg SMX* twice daily for 7 days

Treatment with nitazoxanide* has been shown to be effective in clearing organisms and improving symptoms at the following doses:

• Adults, 500 mg nitazoxanide* orally twice daily for 3 days.
• Children, 200 mg nitazoxanide* orally twice daily for 3 days in patients aged 4–11 years, and 100 mg nitazoxanide* orally twice daily for 3 days in patients aged 1–3 years.

Tinidazole*, paromomycin*, iodoquinol*, and ketoconazole* have also been used for clearing Blastocystis, as presented in case reports or small series (see references).

*Not FDA-approved for this indication.