antiamoebic

Antiamoebic refers to medicines used to treat amoebic infections, most often those caused by Entamoeba histolytica. Amoebiasis ranges from asymptomatic intestinal colonization to invasive disease, including dysentery and liver abscess. Antiamoebic therapy is designed to eradicate parasites from the intestinal lumen and, in invasive cases, to eliminate tissue trophozoites and reduce the risk of relapse or spread.

Therapies are generally categorized as luminal agents, which act within the gut and are poorly absorbed, and tissue-active agents, which reach systemic circulation. In uncomplicated intestinal amoebiasis, a luminal agent alone may be sufficient. In invasive disease or extraintestinal involvement, a tissue-active drug is given first, typically followed by a luminal agent to clear luminal cysts.

Common tissue-active drugs include metronidazole and tinidazole; others such as ornidazole may be used in some regions. Luminal agents include paromomycin, iodoquinol, and diloxanide furoate. Metronidazole or tinidazole disrupts anaerobic protozoal DNA synthesis, while luminal agents act locally in the gut with limited systemic absorption.

Adverse effects vary: metronidazole can cause GI upset, a metallic taste, and, with prolonged use, neuropathy; alcohol consumption may cause a disulfiram-like reaction. Paromomycin and other luminal agents are generally well tolerated but can cause GI disturbance. Proper use depends on disease severity and local guidelines.