Notes on the Treatment of Amoebiasis

NOTES ON THE TREATMENT OF AMOEBIASIS

1. Invasive Intestinal Amoebiasis

Most cases of amoebic dysentery respond to a single adequate course of treatment. Metronidazole/tinidazole are the drugs of choice. Secnidazole, ornidazole, satranidazole are the alternatives. Adjuvant measures for diarrhoea and abdominal pain may be needed. Dehydroemetine is rarely used in the most severe cases to accord faster symptomatic relief. It should be discontinued as soon as acute symptoms are controlled (2–3 days) and metronidazole started. Emetine may also be needed when metronidazole is contraindicated or produces rashes/neurotoxicity.

The above treatment should be followed by a course of luminal amoebicide to eradicate E. histolytica from the colon and to prevent carrier (cyst passing) state.

2. Chronic Intestinal Amoebiasis/Asymptomatic Cyst Passers

These cases are more difficult to treat, two or more repeated courses may be needed. Diloxanide furoate produces high cure rates and is the drug of choice. Nitazoxanide is an alternative. Metronidazole/tinidazole may be given in alternating courses, but are less effective in clearing cysts; they would though cure any latent hepatic infection. A single course of a hydroxyquinoline not extending beyond 2 weeks may be used as third choice.

A tetracycline may be given concurrently with the luminal amoebicide in cases which fail to clear completely.

3. Amoebic Liver Abscess

It is a serious disease; complete eradication of trophozoites from the liver is essential to avoid relapses. Metronidazole/tinidazole are the first choice drugs effective in > 95% cases. Dehydroemetine is to be used only if metronidazole cannot be given for one reason or the other, and in patients not cured by metronidazole. If a big abscess has formed, it may be aspirated.

A luminal amoebicide must be given later to finish the intestinal reservoir of infection. A course of chloroquine may be administered after that of metronidazole/dehydroemetine in those with incomplete response or to ensure that no motile forms survive in the liver.