Amoebiasis medical therapy

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Medical Therapy

E. histolytica infections occur in both the intestine and (in people with symptoms) in tissue of the intestine and/or liver. As a result two different sorts of drugs are needed to rid the body of the infection, one for each location. Metronidazole, or a related drug such a tinidazole, is used to destroy amebae that have invaded tissue. It is rapidly absorbed into the bloodstream and transported to the site of infection. Because it is rapidly absorbed there is almost none remaining in the intestine. Since most of the amebae remain in the intestine when tissue invasion occurs, it is important to get rid of those also or the patient will be at risk of developing another case of invasive disease. Several drugs are available for treating intestinal infections, the most effective of which has been shown to be Paromomycin (also known as Humatin); diloxanide furoate is used in the US. Both types of drug must be used to treat infections, with metronidazole usually being given first, followed by paromomycin or diloxanide. E. dispar does not require treatment, but many laboratories (even in the developed world) do not have the facilities to distinguish this from E. histolytica.

For amebic dysentery a multi-prong approach must be used, starting with one of:

Metronidazole 500-750mg three times a day for 5-10 days
Tinidazole 2g once a day for 3 days is an alternative to metronidazole

In addition to the above, one of the following luminal amebicides should be prescribed as an adjunctive treatment, either concurrently or sequentially, to destroy E. histolytica in the colon:

Paromomycin 500mg three times a day for 10 days
Diloxanide furoate 500mg three times a day for 10 days
Iodoquinol 650mg three times a day for 20 days

For amebic liver abscess:

Metronidazole 400mg three times a day for 10 days
Tinidazole 2g once a day for 6 days is an alternative to metronidazole
Diloxanide furoate 500mg three times a day for 10 days must always be given afterwards.

Antimicrobial Regimen

Entamoeba histolytica

1. Amebic Liver Abscess^[1]

Preferred regimen: (Metronidazole 750 mg PO tid for 10 days OR Tinidazole 2 g PO qd for 5 days) AND (Paromomycin 30 mg/kg/day PO tid for 5-10 days OR Diloxanide furoate 500 mg PO tid for 10 days)
Alternative regimen (1): Nitazoxanide 500 mg bid for 10 days AND (Paromomycin 30 mg/kg/day PO tid for 5-10 days OR Diloxanide furoate 500 mg PO tid for 10 days)
Alternative regimen (2): Tinidazole 2 g PO qd for 5 days AND (Paromomycin 30 mg/kg/day PO tid for 5-10 days OR Diloxanide furoate 500 mg PO tid for 10 days)
Alternative regimen (2): Tinidazole 2 g PO qd for 5 days

2. Amebic Colitis^[2]

Preferred regimen: Metronidazole 500-750 mg PO tid for 7-10 days. Pediatric dose: 35-50 mg/kg per day tid AND (Paromomycin 30 mg/kg/day PO tid for 5-10 days OR Diloxanide furoate 500 mg PO tid for 10 days)
Alternative regimen: Tinidazole 2 g PO qd for 5 days AND (Paromomycin 30 mg/kg/day PO tid for 5-10 days OR Diloxanide furoate 500 mg PO tid for 10 days)

3. Asymptomatic Intestinal Colonization^[3]

Preferred regimen: Paromomycin 30 mg/kg/day PO tid for 5-10 days
Alternative regimen (1): Diloxanide furoate 500 mg PO tid for 10 days
Alternative regimen (2): Diiodohydroxyquin 650 mg PO tid for 20 days for adults and 30 to 40 mg/kg per day tid for 20 days for children

Doses for children are calculated by body weight and a pharmacist should be consulted for help.

Contraindicated Medications

Prednisolone

References

↑ Bennett, John (2015). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Philadelphia, PA: Elsevier/Saunders. ISBN 978-1455748013.
↑ Bennett, John (2015). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Philadelphia, PA: Elsevier/Saunders. ISBN 978-1455748013.
↑ Bennett, John (2015). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Philadelphia, PA: Elsevier/Saunders. ISBN 978-1455748013.

Template:WikiDoc Sources

[1] Bennett, John (2015). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Philadelphia, PA: Elsevier/Saunders. ISBN 978-1455748013.

[2] Bennett, John (2015). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Philadelphia, PA: Elsevier/Saunders. ISBN 978-1455748013.

[3] Bennett, John (2015). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. Philadelphia, PA: Elsevier/Saunders. ISBN 978-1455748013.

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