First-line therapy for hepatic encephalopathy is:

• A. Lactulose
• B. Rifaximin alone
• C. Neomycin
• D. Dialysis

Answer: (A)

The key idea is that initial hepatic encephalopathy treatment aims to rapidly reduce ammonia in the gut. Lactulose does this best because it acidifies the colon, converting ammonia (NH3) to ammonium (NH4+), which is trapped and excreted, and it also has a laxative effect that speeds stooling to remove ammonia-producing substrates. This combination quickly lowers systemic ammonia levels and improves mental status, making lactulose the preferred first-line therapy. Dosing is tailored to achieve about 2–3 soft stools per day, and it can be given orally or by enema if needed.

Rifaximin can help by reducing gut bacteria that produce ammonia, but when used alone it isn’t as effective for the initial control of encephalopathy and is usually added to lactulose for recurrent or persistent cases. Neomycin is less favored due to toxicity. Dialysis isn’t a standard first-line treatment; it’s reserved for severe cases or when other measures fail or in the setting of renal failure to help remove toxins.