Antiamoebic Agents

Antiamoebic Agents

INTRODUCTION

Amoebiasis affects about 10% of the world’s population, causing invasive diseases in about 50 million people and death in about 1,00,000 of these annually. This infection is, especially, common in lower socio-economic groups and institutionalized individuals living under crowded and poor hygienic conditions. Two morphologically identical, but genetically and biochemically distinct, species of Entamoeba (E. histolitica and E. dispar) are the causative organisms. Human beings are the only host for this organisms. Ingested amoebic cysts from contaminated food or water survive and form acid gastric contents and transform them into trophozoites that usually cause colitis which is either acute or chronic (dysentery). In some cases, they target the brain and the liver producing abscesses and systemic diseases.

This parasitic disease is one of the major causes of illness and death in many countries. World Health Organization (WHO) has classified this disease as follows:

1.           Asymptomatic

2.           Symptomatic

a.            Intestinal Amoebiasis

i.           Dysentery

ii.           Nondysenteric colitis

iii.         Amoeboma

iv.          Amoebic appendicitis.

b.           Extraintestinal amoebiasis

i.           Hepatic acute nonsupporative

ii.           Liver abscesses

3.           Cutaneous involvement of other organs

Lung, brain, and spleen without the obvious liver involvement are some examples under this category. Antiamoebic agents are drugs used to treat amoebiasis. The potential drug should be active within the bowel lumen, in the bowel wall, and particularly in the liver. Worldwide, nearly 480 million people are infected with E. histolytica, of whom 10% develope clinical disease. The infection is transmitted exclusively by the faecal—oral route; human beings are the only known hosts.