Which drug is used to treat Amebiasis (Entamoeba histolytica)?

• A. Albendazole
• B. Iodoquinol
• C. Metronidazole
• D. Mebendazole

Answer: (C)

Treating amebiasis caused by Entamoeba histolytica often involves two steps: aggressively addressing the tissue invasion and then eradicating parasites in the intestinal lumen to prevent relapse. Metronidazole is ideal for the first part because it penetrates tissues well and effectively kills the invasive trophozoites responsible for symptoms like colitis and liver abscess. Because it acts in tissue, it serves as the drug of choice for invasive amebiasis. After symptoms improve, a luminal agent is added to clear remaining cysts in the gut; iodoquinol is one example used for this purpose.

Other drugs listed don’t fit as the primary treatment for invasive amebiasis. Albendazole and mebendazole target helminths, not Entamoeba histolytica. Iodoquinol works in the lumen but does not treat tissue invasion by itself, so it isn’t sufficient as a sole therapy for invasive disease.