Azoles in Antiamoebic Chemotherapy

Amoebiasis caused by protozoan parasite Entamoeba histolytica is a major public health problem in both tropical and subtropical regions around the world with 40–50 million symptomatic cases of amoebiasis occur annually and 70000 to 100000 deaths due to this infection. Poverty ignorance overpopulation poor sanitation and malnutrition favor transmission and increased disease burden. Azomycin (a 2-nitroimidazole) an antibiotic isolated in Japan from a streptomycete was the first active compound of the nitroimidazoles to be discovered and acted as the main impetus for the systematic search for drugs with activity against anaerobic protozoa. This led to the synthesis of the 5-nitroimidazole metronidazole (2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethanol) as the drug of choice to treat amoebiasis. Many other nitroimidazoles such as tinidazole nimorazole ornidazole satranidazole secnidazole nimorazole and carnidazole have been used clinically or experimentally to treat the anaerobic pathogenic protozoa but there still exists a dearth for the development of an antiamoebic drug to treat invasive and drug-resistant species.