• Drugs used to treat amebiasis-categories

  • Tissue amebicides:

    • Nitroimidazoles:

      •  metronidazole (Flagyl)

        • very effective in bowel wall and other tissues

        • partially effective & NOT adequate as luminal amebicides {metronidazole (Flagyl) alone may fail to cure as much as 50% of intestinal disease}

    • Emetines:

      •  emetine (generic) and dehydroemetine (Mebadin)

      •  intramuscular injection-act on bowel-wall/tissue organisms; NOT on luminal amebas

    • Chloroquine (Aralen)-primary activity against hepatic amebas

  • Luminal amebicides (active in bowel lumen-not effective against amebas in bowel wall/other tissues)

    •  Dichloroacetamides

      • diloxanide furoate (Furamide)

      • others available outside USA-clefamide, teclozan, etofamide

    •  Halogenated hydroxyquinolines

      • iodoquinol (Yodoxin, Moebequin)

      • available outside the USA-clioquinol

  • Antibiotics

    •  Paromomycin (Humatin) & erythromycin: directly amebicidal

    •  Oral tetracyclines inhibit bacterial associates of bowel luminal E. histolytica-as a result affect luminal amebas

    •  Paromomycin (Humatin)-highly effective; other antibiotics should not be used as monotherapy because of their limited effectiveness

• Drug Treatment of Asymptomatic Intestinal Infection:

  • Management in endemic areas: asymptomatic carriers not treated due to high-risk of reinfection

  • Management in nonendemic regions:

    • Treat asymptomatic carriers with a luminal amebicide:

      •  Drugs of choice-cure frequency: 80%-90% using a single treatment course

        •  diloxanide furoate (Furamide)-fewer side effects

        •  iodoquinol (Yodoxin, Moebequin)

      • Alternative agents (treatment/re-treatment)

        • paromomycin (Humatin)

        • metronidazole (Flagyl) + iodoquinol (Yodoxin, Moebequin) or diloxanide.

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• Drug Treatment of Mild-Moderate Intestinal Infection

  • Treatment of choice: Metronidazole (Flagyl) + a luminal amebicide

  • Some alternative treatments available --

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• Drug Treatment of Severe Intestinal Amebiasis

  • Drugs of choice include metronidazole (Flagyl) plus diloxanide furoate (Furamide) or iodoquinol (Yodoxin, Moebequin);

    • If parenteral administration is initially required, use intravenous metronidazole (Flagyl) then oral treatment when possible

  • Alternative drugs include:

    • a tetracycline + diloxanide furoate (Furamide) or iodoquinol (Yodoxin, Moebequin), followed by chloroquine (Aralen)

    • If parenteral treatment is initially required:

      • dehydroemetine (Mebadin) or emetine (generic), followed by

        • a tetracycline + diloxanide furoate (Furamide) or iodoquinol (Yodoxin, Moebequin) followed by

        • chloroquine (Aralen)

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• Hepatic Abscess:

  • Nonpharmacological: bed rest/hospitalization

  • Ultrasound Radiological Study of amebic liver abscess: http://brighamrad.harvard.edu/Cases/bwh/hcache/24/full.html

    • courtesy of:Department of Radiology, Brigham and Women's Hospital, Harvard Medical School

  •  Drug treatments of choice:

    •  metronidazole (Flagyl)-ten day protocol/cure rate: > 95% its (uncomplicated cases)

      •  For treatment failure: follow metronidazole (Flagyl) protocol with chloroquine (Aralen)

      •  Additional advantage of metronidazole (Flagyl): effective against bacterial liver abscess, as well -- due to anaerobic bacteria

    • Also required: luminal amebicide {independent of positive stools}

      •  diloxanide furoate (Furamide)

      •  iodoquinol (Yodoxin, Moebequin)

  • Potentially more toxic alternative drugs:

    •  dehydroemetine (Mebadin)

    •  emetine (generic)

Hepatic Abscess

Specific Form of Amebiasis	Drug (s) of Choice	Alternative Drug(s)
Hepatic Abscess	Metronidazole (Flagyl) plus  diloxanide furoate (Furamide) OR  idoquinol (Yodoxin) FOLLOWED BY Chloroquine (Aralen)	Dehydroemetine (Mebadin) or emetine (generic) FOLLOWED BY Chloroquine (Aralen) PLUS diloxanide furoate (Furamide) or iodoquinol (Yodoxin, Moebequin)

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• Ameboma/Extraintestinal amebiasis

  • Drug or choice: metronidazole (Flagyl)

  •  Alternative drugs: dehydroemetine (Mebadin) oremetine (generic)

  •  NOT ACCEPTABLE: chloroquine (Aralen)-insufficient tissue concentration (except hepatic) to be effective

  • Concurrent luminal amebicide also required.

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