Comparative Pharmacology
Head-to-head clinical analysis: DUPHALAC versus POLYETHYLENE GLYCOL 3350.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DUPHALAC versus POLYETHYLENE GLYCOL 3350.
DUPHALAC vs POLYETHYLENE GLYCOL 3350
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Duphalac (lactulose) is a synthetic disaccharide that is not absorbed in the gastrointestinal tract. It is metabolized by colonic bacteria to short-chain fatty acids (e.g., acetic, lactic, formic acids), which lower colonic pH. This acidic environment favors the conversion of ammonia (NH3) to ammonium (NH4+), which is trapped in the colon and excreted in feces, thereby reducing systemic ammonia absorption. Additionally, the osmotic effect of lactulose and its metabolites draws water into the colon, producing a laxative effect.
Osmotic laxative. Polyethylene glycol 3350 is a non-absorbable polymer that retains water in the colon via hydrogen bonding, increasing stool water content and stimulating defecation.
Oral: 15-30 mL once daily, may increase to 30-45 mL twice daily if needed. Rectal (enema): 150-300 mL as a single dose.
17 g (1 capful or packet) dissolved in 4–8 oz (120–240 mL) water, administered orally once daily for constipation; for colonoscopy preparation, 240 g (4 L of solution) ingested at 240 mL every 10–15 minutes.
None Documented
None Documented
Not applicable; systemic exposure is negligible. Orally administered lactulose acts locally in the colon.
Terminal elimination half-life is 1-2 hours in patients with normal renal function; prolonged in renal impairment, but clinical impact minimal due to primarily fecal elimination.
Lactulose is not absorbed from the gastrointestinal tract; it is excreted unchanged in feces (>99%).
Renal: approximately 20% excreted unchanged; Fecal: approximately 80% eliminated unchanged in feces.
Category C
Category C
Osmotic Laxative
Osmotic Laxative