The treatment of choice for intestinal and extraintestinal amoebiasis is
a. The drugs used to treat amebiasis can be classified according to their primary site of action.
b. Luminal amebicides are poorly absorbed and reach high concentrations in the bowel, but their activity is limited to cysts and trophozoites close to the mucosa.
c. Only two luminal drugs are available in the United States: iodoquinol and paromomycin.
d. Indications for the use of luminal agents include eradication of cysts in patients with colitis or a liver abscess and treatment of asymptomatic carriers.
e. The majority of asymptomatic individuals who pass cysts are colonized with E. dispar, which does not warrant specific therapy.
f. However, it is prudent to treat asymptomatic individuals who pass cysts unless E. dispar colonization can be definitively demonstrated by specific antigen-detection tests.
g. Patients with amebic colitis should be treated with intravenous or oral metronidazole. Side effects include nausea, vomiting, abdominal discomfort, and a disulfiram-like reaction.
h. Another longer-acting imidazole compound, tinidazole, is also effective and was recently approved in the United States.
i. All patients should also receive a full course of therapy with a luminal agent, since metronidazole does not eradicate cysts.