Amebiasis is an infection of the body by the protozoa Entamoeba histolytica, which most often affects the large intestine, although they can also affect the lungs, liver, brain, and other organs. This disease can attack the gastrointestinal tract without any clinical symptoms, with moderately expressed clinical symptoms (diarrhea, cramps, meteorism), as well as with symptoms of acute ameba dysentery, which is accompanied by bloody diarrhea, vomiting, fever, and dehydration. The presence of the protozoan microorganisms E. his-tolytica in other organs can cause liver death, ameba hepatitis, and lung abscess. Cases of heart damage (causing pericarditis) and brain damage (leading to brain abscess) have been described.
The microorganisms are passed from one person to another by way of amebic cysts, a form of ameba existence in which the protozoa have maximum resistivity to external influences The cysts are not damaged by gastric juices, and therefore, they pass into the intestines where they can develop into trophozoites, which attack the mucous membranes of the intestines, are absorbed, and can penetrate further into other organs. E. histolytica, the cause of amebiasis, has a relatively complex life cycle in the host organism. The secreted cysts (in an unchanged form) are the cause of new infections. There are many drugs used for treating amebiasis. However, not one of them can be considered completely effective since this microorganism is very resistant. Drugs used for treating amebiasis can be characterized according to their primary location of action. For example, a few drugs (iodoquinol, diloxanide, paromomycin) are only active against amebas that are localized in the lumen of the intestine and other tissues, and they are used for amebic dysentery and hepatic abscesses. The third group (metronidazole, tinidazole) is active against amebas localized both inside and outside the intestine.
lodoquinol: Iodoquinol, 5,7-diiodo-8-quinolinol (37.2.2), is made by iodination of 8-oxyquinoline (37.2.1) using a mixture of potassium iodide/potassium iodate. The initial 8-hydroxyquinolin (37.2.1) is made from 2-aminophenol and glycerol in the presence of sulfuric acid and nitrobenzene (Skraup synthesis) [39,40].
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