Comparative Pharmacology
Head-to-head clinical analysis: DUPHALAC versus GOLYTELY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DUPHALAC versus GOLYTELY.
DUPHALAC vs GOLYTELY
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.
Polyethylene glycol 3350 is an osmotic laxative that induces diarrhea by retaining water in the bowel lumen through osmotic activity. Electrolytes (sodium sulfate, potassium chloride, sodium bicarbonate) prevent significant electrolyte absorption or loss.
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.
240 mL (oral) every 10 minutes until 4 L consumed or rectal effluent is clear; typically 4 L total over 3-4 hours.
None Documented
None Documented
Not applicable; systemic exposure is negligible. Orally administered lactulose acts locally in the colon.
Not applicable (PEG 3350 is not significantly absorbed; effective half-life in GI tract is approximately 2-4 hours for colonic clearance).
Lactulose is not absorbed from the gastrointestinal tract; it is excreted unchanged in feces (>99%).
Primarily fecal elimination of unabsorbed polyethylene glycol 3350. Minimal systemic absorption (<0.06%), less than 0.06% recovered in urine as intact PEG 3350; electrocytes and sulfate (from sodium sulfate) are renally excreted.
Category C
Category C
Osmotic Laxative
Osmotic Laxative