Comparative Pharmacology
Head-to-head clinical analysis: DUPHALAC versus PEG LYTE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DUPHALAC versus PEG LYTE.
DUPHALAC vs PEG-LYTE
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.
PEG-LYTE is an osmotic laxative that induces diarrhea by retaining water in the colon through the non-absorbable polyethylene glycol (PEG) and electrolytes, which prevent dehydration and electrolyte imbalance during bowel cleansing.
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.
4 liters orally as a single dose or in divided doses for colonoscopy preparation.
None Documented
None Documented
Not applicable; systemic exposure is negligible. Orally administered lactulose acts locally in the colon.
Not applicable; PEG-3350 is minimally absorbed (<0.06%), thus systemic half-life is not clinically relevant. Local gut transit time ~1-2 hours.
Lactulose is not absorbed from the gastrointestinal tract; it is excreted unchanged in feces (>99%).
Primarily fecal (98-99%) as unchanged polyethylene glycol (PEG) 3350; negligible renal excretion (<0.2%). Electrolytes (sodium, potassium, bicarbonate) are partially absorbed and excreted renally.
Category C
Category C
Osmotic Laxative
Osmotic Laxative