Treatment is recommended only for symptomatic infection. Iodoquinol,
tetracycline, and paromomycin are recommended treatments.1,11 However,
tetracycline and paromomycin are investigational due to a lack of
clinical studies.1 Metronidazole may be effective. Adults
should be treated with iodoquinol at a dose of 650 mg tid for 20
days1,11,13and children at a dose of 40 mg/kg per
day (maximum 2 gm/day) divided tid for 20 days.1,14Iodoquinol
should be taken with food. Alternatively, paromomycin at a dose
of 500 mg tid in adults1,11,13 and 25 to 35 mg/kg
per day in divided doses for 7 days in children1,14 may
be more effective than iodoquinol but may not be readily available.
The syrup form of paromomycin is no longer available in the United
States. Tetracycline may be used in adults (500 mg qid for 10 days)
and in children at least 8 years of age (10 mg/kg qid,
for a maximum of 2 gm/day for 10 days), given on an empty
stomach.1,14 Metronidazole dosing includes 500
to 750 mg tid for 10 days in adults1,11 and 20
to 40 mg/kg per day divided tid for 10 days (maximum 2
gm/day) in children.1,14 Due to several
potential drug interactions and many adverse reactions from these
medications, the need for therapy should be evaluated on a case
by case basis, and treatment options should be discussed with the
patient and/or family.1
Nitazoxanide, a thiazolide derivative, which has a broad spectrum of
antiprotozoal and antihelminthic activity, may have some value in
treating children whose persistent diarrhea could be due to agents
like Blastocystis hominis, D fragilis, and other
protozoa. However, no specific studies examining the effectiveness
of this drug alone on D fragilis in children have
been published. Treating D fragilis with a combination
of agents, including furazolidone, nitazoxanide, and secnidazole,
has been recommended by a group of physicians in Australia.15
Educating patients and families about judicious hand-washing
and improved personal hygiene is essential, as well as disinfecting
surfaces and equipment handled by infected persons. In childcare
centers, diapering areas should be separated from the food-preparation site.