Comparative Pharmacology
Head-to-head clinical analysis: DUPHALAC versus PLENVU.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DUPHALAC versus PLENVU.
DUPHALAC vs PLENVU
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.
PLENVU is an osmotic laxative that induces bowel cleansing by causing water retention in the colon, leading to increased intraluminal pressure and stimulation of peristalsis. Its components (polyethylene glycol 3350, sodium ascorbate, ascorbic acid, sodium sulfate) act synergistically to produce a cathartic effect.
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.
2 sachets (each containing ascorbic acid 4.7g, macrogol 3350 52.5g, sodium ascorbate 5.9g, sodium sulfate 3.75g) dissolved in water to a total volume of 500mL, administered orally as a split-dose regimen: first dose (2 sachets in 500mL water) at 6-9 pm on the day before colonoscopy, followed by additional 500mL of clear fluids; second dose (2 sachets in 500mL water) on the morning of colonoscopy, completed at least 2 hours before the procedure, followed by additional 500mL of clear fluids.
None Documented
None Documented
Not applicable; systemic exposure is negligible. Orally administered lactulose acts locally in the colon.
Not applicable (non-absorbed agent); systemic absorption is minimal, so no terminal half-life is defined.
Lactulose is not absorbed from the gastrointestinal tract; it is excreted unchanged in feces (>99%).
Primarily fecal (90-95%) as unabsorbed drug; renal excretion is negligible (<1%).
Category C
Category C
Osmotic Laxative
Osmotic Laxative