Comparative Pharmacology
Head-to-head clinical analysis: CEPHULAC versus SODIUM PICOSULFATE MAGNESIUM OXIDE AND ANHYDROUS CITRIC ACID.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CEPHULAC versus SODIUM PICOSULFATE MAGNESIUM OXIDE AND ANHYDROUS CITRIC ACID.
CEPHULAC vs SODIUM PICOSULFATE, MAGNESIUM OXIDE AND ANHYDROUS CITRIC ACID
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Lactulose, a synthetic disaccharide, is not absorbed from the gastrointestinal tract. It is metabolized by colonic bacteria to form short-chain fatty acids (e.g., lactic, acetic, formic acids), which acidify the colonic contents. In hepatic encephalopathy, the acidic environment converts ammonia (NH3) to ammonium (NH4+), which is poorly absorbed and excreted in feces. Additionally, the osmotic effect of lactulose draws water into the colon, softening stools and increasing bowel movements.
Sodium picosulfate is a stimulant laxative that is converted by colonic bacteria to the active metabolite bis-(p-hydroxyphenyl)-pyridyl-2-methane, which acts on the colonic mucosa to stimulate peristalsis and increase water and electrolyte secretion. Magnesium oxide and citric acid react in solution to form magnesium citrate, an osmotic laxative that draws water into the intestinal lumen, increasing stool volume and promoting bowel evacuation.
30-45 mL (6.67-10 g lactulose) orally 3-4 times daily for constipation; for hepatic encephalopathy, 30-45 mL orally 3-4 times daily titrated to produce 2-3 soft stools per day, or 300 mL in 700 mL of water or saline as retention enema for 30-60 min every 4-6 hours.
Adults: 10 mg sodium picosulfate, 3.5 g magnesium oxide, and 10.97 g anhydrous citric acid (reconstituted in water) as a single oral dose, followed by clear liquids. Two doses may be used in a split-dose regimen: first dose evening before procedure, second dose day of procedure at least 5 hours prior.
None Documented
None Documented
Terminal elimination half-life is 7-10 hours (renal impairment: prolonged); systemic absorption is minimal (<3%) after oral administration, so half-life reflects clearance of absorbed fraction.
Sodium picosulfate active metabolite BHPM: terminal half-life approximately 7.4 hours; clinical duration of laxative effect extends beyond half-life due to colonic residence.
Primarily renal (20-30% as unchanged drug) and fecal (up to 70% as unmetabolized drug via biliary elimination; following gastric acid-mediated degradation, only 5-10% reaches urine as intact lactulose; hepatic metabolism is negligible).
Sodium picosulfate is primarily excreted in feces (biliary/fecal elimination) as active metabolite BHPM; <5% renal. Magnesium oxide is excreted renally as magnesium ions; absorbed magnesium is eliminated via kidneys. Anhydrous citric acid is metabolized in the Krebs cycle; minimal renal excretion.
Category C
Category C
Laxative
Laxative