Comparative Pharmacology
Head-to-head clinical analysis: CEPHULAC versus CHOLAC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CEPHULAC versus CHOLAC.
CEPHULAC vs CHOLAC
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Lactulose, a synthetic disaccharide, is not absorbed from the gastrointestinal tract. It is metabolized by colonic bacteria to form short-chain fatty acids (e.g., lactic, acetic, formic acids), which acidify the colonic contents. In hepatic encephalopathy, the acidic environment converts ammonia (NH3) to ammonium (NH4+), which is poorly absorbed and excreted in feces. Additionally, the osmotic effect of lactulose draws water into the colon, softening stools and increasing bowel movements.
Lactulose is a synthetic disaccharide that is not absorbed in the small intestine. It is metabolized by colonic bacteria to short-chain fatty acids, primarily lactic acid and acetic acid, which lower the colonic pH. This acidification traps ammonia (NH3) as ammonium (NH4+) in the gut lumen, reducing serum ammonia levels. Additionally, the osmotic effect of lactulose draws water into the colon, producing a laxative effect.
30-45 mL (6.67-10 g lactulose) orally 3-4 times daily for constipation; for hepatic encephalopathy, 30-45 mL orally 3-4 times daily titrated to produce 2-3 soft stools per day, or 300 mL in 700 mL of water or saline as retention enema for 30-60 min every 4-6 hours.
15-30 mL (10-20 g lactulose) orally once daily, titrated to produce 2-3 soft stools per day; maximum dose 60 mL/day. For hepatic encephalopathy: 30-45 mL (20-30 g) orally 3-4 times daily, titrated to 2-3 soft stools per day.
None Documented
None Documented
Terminal elimination half-life is 7-10 hours (renal impairment: prolonged); systemic absorption is minimal (<3%) after oral administration, so half-life reflects clearance of absorbed fraction.
0.5-1.5 hours for lactulose; active metabolites (e.g., acetic acid) have negligible systemic half-life due to rapid local metabolism.
Primarily renal (20-30% as unchanged drug) and fecal (up to 70% as unmetabolized drug via biliary elimination; following gastric acid-mediated degradation, only 5-10% reaches urine as intact lactulose; hepatic metabolism is negligible).
Primarily fecal (biliary excretion of unchanged drug and metabolites); minimal renal excretion (<5%).
Category C
Category C
Laxative
Laxative