(diiodohydroxyquin) is a halogenated hydroxyquino-line. It is an effective
luminal amebicide that is commonly used with metronidazole to treat amebic
infections. Pharmacokinetic data are incomplete but 90% of the drug is retained
in the intes-tine and excreted in the feces. The remainder enters the
circula-tion, has a half-life of 11–14 hours, and is excreted in the urine as
mechanism of action of iodoquinol against trophozoites is unknown. It is
effective against organisms in the bowel lumen but not against trophozoites in
the intestinal wall or extraintestinal tissues.
adverse effects include diarrhea—which usually stops after several
days—anorexia, nausea, vomiting, abdominal pain, headache, rash, and pruritus.
The drug may increase protein-bound serum iodine, leading to a decrease in
measured 131I uptake that persists for
months. Some halogenated hydroxyquinolines can produce severe neurotoxicity
with prolonged use at greater than recommended doses. Iodoquinol is not known
to produce these effects at its recommended dosage, and this dosage should
never be exceeded.
Iodoquinol should be
taken with meals to limit gastrointestinal toxicity. It should be used with
caution in patients with optic neu-ropathy, renal or thyroid disease, or
nonamebic hepatic disease. The drug should be discontinued if it produces
persistent diarrhea or signs of iodine toxicity (dermatitis, urticaria,
pruritus, fever). It is contraindicated in patients with intolerance to iodine.