Comparative Pharmacology
Head-to-head clinical analysis: PEG LYTE versus PORTALAC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PEG LYTE versus PORTALAC.
PEG-LYTE vs PORTALAC
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
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.
4 liters orally as a single dose or in divided doses for colonoscopy preparation.
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.
None Documented
None Documented
Not applicable; PEG-3350 is minimally absorbed (<0.06%), thus systemic half-life is not clinically relevant. Local gut transit time ~1-2 hours.
1.7-2.0 hours (terminal); clinical context: short t1/2 allows rapid dose adjustment in hepatic encephalopathy.
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.
Renal: ~40% as unchanged drug; fecal: ~60% as metabolites (biliary excretion of conjugates and lactulose).
Category C
Category C
Osmotic Laxative
Osmotic Laxative