Which drug is used as an antiamebic agent?

• A. Amoxicillin
• B. Metronidazole
• C. Tinidazole
• D. Ciprofloxacin

Answer: (B)

Antiamebic therapy relies on nitroimidazole drugs that are active against Entamoeba histolytica, especially the invasive tissue forms. Metronidazole is the standard tissue-active antiamebic agent. It becomes active in the anaerobic environment of the parasite, where it forms reactive metabolites that damage the parasite’s DNA, effectively killing trophozoites in tissues and treating invasive amebiasis and liver abscesses. After clearing tissue infection, a luminal agent is often used to eradicate parasites in the intestinal lumen.

Tinidazole works similarly and is another antiamebic option, but metronidazole is the classic and most commonly referenced drug for this purpose. Amoxicillin and ciprofloxacin are antibacterial agents and do not target Entamoeba histolytica, so they are not used as antiamebic drugs.