Comparative Pharmacology

Head-to-head clinical analysis: DUPHALAC versus PORTALAC.

Peer-Reviewed Evidence

Differential Analysis

DUPHALAC vs PORTALAC

Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.

DUPHALAC

Osmotic Laxative

Category C

PORTALAC

Osmotic Laxative

Category C

Head-to-Head

Clinical Matrix

Mechanism of Action

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.

Lactulose is a synthetic disaccharide that is not absorbed from the gastrointestinal tract. It is metabolized by colonic bacteria to short-chain fatty acids (e.g., acetic, lactic, and formic acid), resulting in acidification of colonic contents and an increase in osmotic pressure, which stimulates bowel evacuation. In hepatic encephalopathy, acidification reduces blood ammonia levels by converting NH3 to NH4+ in the colon, inhibiting ammonia absorption.

Clinical Dosing

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.

Initial: 15-30 mL (10-20 g lactulose) orally, 2-3 times daily; titrate to 2-3 soft stools daily. For acute hepatic encephalopathy: 30-45 mL (20-30 g) orally every hour until evacuation, then 3-4 times daily.

Direct Interaction