A 35-year-old man presents with right upper quadrant pain and fever. Ultrasound shows a solitary hypoechoic lesion in the right lobe of the liver. Aspiration yields chocolate-brown ('anchovy sauce') fluid that is odourless. Microscopy of the fluid reveals no trophozoites. Serology for Entamoeba histolytica is strongly positive. The BEST drug of choice for treatment of this amoebic liver abscess is:
- A Diloxanide furoate
- B Metronidazole ✓
- C Chloroquine alone
- D Paromomycin
Correct answer: B. Metronidazole
Explanation
Metronidazole (a 5-nitroimidazole) is the drug of choice for invasive amoebiasis including amoebic liver abscess, as it acts on tissue trophozoites. Diloxanide furoate is a luminal amoebicide used to eradicate intestinal cysts after metronidazole treatment; it is ineffective against tissue forms. Chloroquine alone is used as an adjunct when metronidazole is unavailable. Paromomycin is a luminal agent for asymptomatic cyst passers.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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