Comparative Pharmacology
Head-to-head clinical analysis: DUPHALAC versus SUTAB.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DUPHALAC versus SUTAB.
DUPHALAC vs SUTAB
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.
SUTAB is a combination tablet consisting of sodium sulfate, magnesium sulfate, and potassium chloride. It acts as an osmotic laxative by drawing water into the bowel lumen through the osmotic effect of sulfate ions, inducing colonic evacuation. Additionally, magnesium ions enhance this effect by attracting water via osmotic pressure and stimulating the release of cholecystokinin, which promotes peristalsis.
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.
24 tablets administered as 4 tablets every 15 minutes, total dose of 17.5 g sodium sulfate, 3.13 g magnesium sulfate, and 1.64 g potassium sulfate, orally, with water, the evening before colonoscopy.
None Documented
None Documented
Not applicable; systemic exposure is negligible. Orally administered lactulose acts locally in the colon.
Terminal elimination half-life: 6-8 hours in adults with normal renal function; prolonged to 20-40 hours in end-stage renal disease.
Lactulose is not absorbed from the gastrointestinal tract; it is excreted unchanged in feces (>99%).
Primarily renal excretion (65-75% unchanged) with minor biliary/fecal elimination (<10%). Total body clearance approximates renal blood flow.
Category C
Category C
Osmotic Laxative
Osmotic Laxative