SPECIFIC DRUGS USED IN THE TREATMENT OF AMEBIASIS
a. Metronidazole (Flagyl). Metronidazole is used in the treatment of
amebiasis, an infection of Entamoeba histolytica. Metronidazole is very effective in the
treatment of acute intestinal amebiasis and amebic liver abscesses, symptomatic
trichomoniasis, asymptomatic trichomonias is, and asymptomatic consort's T. vaginalis.
(1) Metronidazole is a chemically synthesized drug with trichomonacidal
properties selected for obligatory anaerobic and facultative anaerobic organisms. Oral
absorption of the drug is good, with both oral and IV administration, resulting in wide
distribution to all body tissues, to include the CSF and saliva. The bulk of the drug
remains unchanged, but active metabolites are formed. Sixty to eighty percent of the
drug is eliminated in the urine, with a small portion excreted through the feces.
(2) Adverse reactions associated with this agent are not usually severe and
include nausea, anorexia (loss of appetite), diarrhea, abdominal cramping, vertigo, and
numbness of extremities. Convulsive seizures have also been reported. Patient taking
metronidazole should be told to avoid alcohol, since alcohol and metronidazole may
produce an Antabuse-type reaction (that is, produce nausea, vomiting, flushing, and
abdominal cramps in the patient). Patients using this drug should be monitored for
candidiasis super-infection. Metronidazole has been demonstrated to be a carcinogenic
agent in some animals. Thus, as with all drugs, its use should be limited except in
cases in which it is clearly indicated. In those cases, the prescriber should use the
lowest effective dose. This product should not be prescribed to females who are in their
first trimester of pregnancy because of the drug's effects on the fetus.
(3) In amebiasis, the adult dose of metronidazole (for acute amebic
dysentery) is 750 milligrams by mouth three times daily for 5 to 10 days. In the
treatment of amebic liver abscess, the dose of metronidazole is 500 to 750 milligrams
taken orally three times daily for 5 to 10 days.
b. Iodoquinol (Yodoxin). Iodoquinol is used in the treatment of amebiasis.
This medication is especially destructive to amoeba in the intestinal tract. Occasional
toxic effects associated with iodoquinol include rash, acne, nausea, and diarrhea.
Patients who find the tablets too large to swallow whole should be instructed to crush
the tablets and mix them with a small quantity of chocolate syrup or applesauce.
2-7. SPECIFIC DRUGS USED IN THE TREATMENT OF PARASITIC WORM
When there is an infestation by two or more species of intestinal worms, the
Ascaris infestation should always be treated first. Surgery may be required
when heavy infestation with Ascaris lumbricoides produces intestinal
perforation. When many worms are present, there can be partial or complete
obstruction of the small intestine.