Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ENULOSE vs CHOLAC
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Lactulose is a synthetic disaccharide that is not absorbed from the gastrointestinal tract. It is metabolized by colonic bacteria to form low molecular weight organic acids, which lower the colonic p H and increase osmotic pressure, resulting in increased stool volume and laxative effect. In hepatic encephalopathy, the acidification of the colon inhibits the growth of ammonia-producing bacteria and promotes the conversion of ammonia to ammonium ion, which is trapped in the colon and excreted, thereby reducing systemic ammonia levels.
Lactulose is a synthetic disaccharide that is not absorbed in the small intestine. It is metabolized by colonic bacteria to short-chain fatty acids, primarily lactic acid and acetic acid, which lower the colonic p H. This acidification traps ammonia (NH3) as ammonium (NH4+) in the gut lumen, reducing serum ammonia levels. Additionally, the osmotic effect of lactulose draws water into the colon, producing a laxative effect.
Treatment of constipation,Portal-systemic encephalopathy (including the prevention and treatment of hepatic coma)
Treatment of hepatic encephalopathy (portal-systemic encephalopathy) in patients with acute and chronic liver disease,Constipation (including chronic idiopathic constipation)
15-45 m L orally once daily, titrated to produce 2-3 soft stools per day. Maximum 60 m L per day.
15-30 m L (10-20 g lactulose) orally once daily, titrated to produce 2-3 soft stools per day; maximum dose 60 m L/day. For hepatic encephalopathy: 30-45 m L (20-30 g) orally 3-4 times daily, titrated to 2-3 soft stools per day.
Terminal elimination half-life is 2.1 hours in normal renal function; prolonged to up to 6 hours in renal impairment.
0.5-1.5 hours for lactulose; active metabolites (e.g., acetic acid) have negligible systemic half-life due to rapid local metabolism.
Lactulose is not metabolized in the human small intestine due to the absence of appropriate enzymes. It reaches the colon unchanged and is fermented by colonic bacteria (e.g., Lactobacillus, Bacteroides) into short-chain fatty acids (lactic acid, acetic acid, and formic acid) and gases (hydrogen, carbon dioxide).
Not absorbed systemically. Metabolized by colonic bacteria (e.g., Lactobacillus, Bacteroides) to lactic acid, acetic acid, and other short-chain fatty acids.
Primarily renal (95% unchanged by glomerular filtration); biliary/fecal less than 5%.
Primarily fecal (biliary excretion of unchanged drug and metabolites); minimal renal excretion (<5%).
Negligible (<1%), not bound to plasma proteins.
Negligible (<1%); not significantly bound to plasma proteins.
Vd approximately 0.25 L/kg, primarily confined to extracellular fluid.
Approximately 0.2 L/kg; indicates distribution primarily in extracellular fluid.
Oral: very low (<3%) as minimally absorbed; rectal: negligible systemic absorption.
Oral: <2% systemic bioavailability due to extensive first-pass metabolism and local gut action; rectal: minimal systemic absorption.
No dose adjustment required for renal impairment; use with caution in severe renal impairment due to electrolyte disturbances.
No dose adjustment required for renal impairment.
No specific adjustment recommended; monitor for electrolyte imbalances in severe hepatic impairment.
No specific Child-Pugh based adjustments. Use with caution in severe hepatic impairment due to risk of electrolyte disturbances; monitor serum electrolytes.
Infants and children: 2.5-10 m L orally once daily, adjusted to produce 2-3 soft stools per day. Maximum 40 m L per day.
Infants: 2.5-10 m L/day in divided doses. Children: 40-90 mg/kg/day (as lactulose) divided 1-2 times daily, titrated to produce soft stools. For hepatic encephalopathy: 2.5-10 m L (1.7-6.7 g) orally 3-4 times daily, titrated to 2-3 soft stools per day.
Start at lower end of dosing range (15-30 m L daily) due to increased risk of electrolyte disturbances and dehydration. Monitor serum electrolytes.
Initiate at lower end of dosing range (15 m L once daily) and titrate slowly to avoid diarrhea and electrolyte imbalance; monitor renal function and electrolytes.
None.
No FDA black box warning.
Diabetic patients should use with caution due to the sugar content. Prolonged use may lead to electrolyte disturbances (e.g., hypernatremia, hypokalemia). Use with caution in patients with galactosemia or lactose intolerance, as lactulose may contain trace amounts of lactose. Excessive dosing may cause diarrhea and fluid loss.
Electrolyte disturbances (e.g., hypernatremia) may occur, especially with prolonged use or in patients with renal impairment,Diarrhea can lead to fluid and electrolyte loss; dosage should be adjusted to produce 2-3 soft stools per day,Galactose content: lactulose contains galactose and lactose; use with caution in patients with galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption,Risk of colonic perforation in patients with severe colonic ulceration, toxic megacolon, or gastrointestinal obstruction
Patients with galactosemia (since lactulose contains galactose and may increase galactose levels), intestinal obstruction, or a history of hypersensitivity to lactulose or any component of the formulation.
Patients with galactosemia (due to galactose content),Gastrointestinal obstruction (including ileus),Hypersensitivity to lactulose or any component of the formulation
No significant food interactions. May be mixed with fruit juice, water, or milk to mask sweet taste. Lactose-containing products may cause additional gas and bloating in lactose-intolerant patients.
No specific food restrictions. Mixing with fruit juice, water, or milk may improve taste. Avoid excessive intake of dairy products if lactose intolerant (lactulose may contain small amounts of lactose).
Pregnancy Category B. No evidence of teratogenicity in animal studies; inadequate human data in first trimester. Second and third trimester: No known fetal risks associated with therapeutic doses.
Lactulose is not absorbed systemically; no teratogenic effects reported in animal studies or human case reports. FDA Pregnancy Category B. Trimester-specific risks: no known fetal harm in any trimester.
Excreted in breast milk in small amounts; M/P ratio not established. Considered compatible with breastfeeding, but monitor infant for gastrointestinal effects.
Excretion into breast milk is negligible due to minimal systemic absorption. M/P ratio not determined. Considered compatible with breastfeeding.
No pharmacokinetic changes requiring dose adjustment during pregnancy. Standard dosing applies.
No dose adjustment required during pregnancy; pharmacokinetics unchanged due to localized GI action.
ENULOSE (lactulose) is a non-absorbable disaccharide used for constipation and hepatic encephalopathy. Monitor for electrolyte disturbances, especially hypernatremia, with prolonged use. In hepatic encephalopathy, titrate to 2-3 soft stools per day. Onset of action for constipation is 24-48 hours. Avoid in patients with galactosemia.
Cholac (lactulose) is used for constipation and hepatic encephalopathy. Monitor for diarrhea and electrolyte imbalances. In hepatic encephalopathy, titrate dose to achieve 2-3 soft stools per day. Syrup can be mixed with fruit juice or water to improve palatability. Onset of action is 24-48 hours for constipation; for encephalopathy, effects may take several days.
Take with or without food. Mix with juice, water, or milk to improve taste.,For constipation: effect may take 24-48 hours. Do not exceed prescribed dose.,For hepatic encephalopathy: maintain 2-3 soft stools daily; adjust dose as directed.,Common side effects include bloating, gas, and cramping. These usually improve with continued use.,Contact your doctor if you experience severe diarrhea, vomiting, or signs of dehydration.,Store at room temperature, away from heat and moisture.
Take exactly as prescribed. Do not change dose without consulting your doctor.,For constipation, effects may take up to 48 hours. Do not use other laxatives unless advised.,For liver disease, it helps reduce ammonia levels. Aim for 2-3 soft bowel movements daily.,May cause gas, bloating, or stomach cramps, which usually decrease over time.,Contact doctor if you have severe diarrhea, vomiting, or signs of dehydration.,Store at room temperature, away from heat and direct light.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about ENULOSE vs CHOLAC, answered by our medical review team.
ENULOSE is a Laxative that works by Lactulose is a synthetic disaccharide that is not absorbed from the gastrointestinal tract. It is metabolized by colonic bacteria to form low molecular weight organic acids, which lower the colonic p H and increase osmotic pressure, resulting in increased stool volume and laxative effect. In hepatic encephalopathy, the acidification of the colon inhibits the growth of ammonia-producing bacteria and promotes the conversion of ammonia to ammonium ion, which is trapped in the colon and excreted, thereby reducing systemic ammonia levels.. CHOLAC is a Laxative that works by Lactulose is a synthetic disaccharide that is not absorbed in the small intestine. It is metabolized by colonic bacteria to short-chain fatty acids, primarily lactic acid and acetic acid, which lower the colonic p H. This acidification traps ammonia (NH3) as ammonium (NH4+) in the gut lumen, reducing serum ammonia levels. Additionally, the osmotic effect of lactulose draws water into the colon, producing a laxative effect.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ENULOSE and CHOLAC depend on the specific clinical indication. These are both Laxative agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ENULOSE is: 15-45 m L orally once daily, titrated to produce 2-3 soft stools per day. Maximum 60 m L per day.. The standard adult dose of CHOLAC is: 15-30 m L (10-20 g lactulose) orally once daily, titrated to produce 2-3 soft stools per day; maximum dose 60 m L/day. For hepatic encephalopathy: 30-45 m L (20-30 g) orally 3-4 times daily, titrated to 2-3 soft stools per day.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ENULOSE and CHOLAC in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ENULOSE is classified as Category C. Pregnancy Category B. No evidence of teratogenicity in animal studies; inadequate human data in first trimester. Second and third trimester: No known fetal risks associated with th. CHOLAC is classified as Category C. Lactulose is not absorbed systemically; no teratogenic effects reported in animal studies or human case reports. FDA Pregnancy Category B. Trimester-specific risks: no known fetal . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.