This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
A patient has hepatic encephalopathy, the drug used for gut sterilization in this patient is - 
Select and explain. 
A. Neomycin, B. Netilmycin, C. Bleomycin, D. None of the above
A: Neomycin
Answer: A: Neomycin 
Explanation: Ans. is 'a' i.e., Neomycin o Normally NH, is produced by colonic bacteria. This is absorbed and conveed to urea by liver. In severe hepatic failure, detoxication of NH3 does not occur, blood NH3 level rise and produce encephalopathy. Neomycin, by suppressing intestinal flora, diminishes NH3 production and lowers its blood level; clinical improvement is seen within 2-3 days. o Because of toxic potential of neomycin, lactulose is preferred.