Generic Medicine Info
Indications and Dosage
Hepatic encephalopathy
Adult: As 3.335 g/5 mL solution: Initially, 30-45 mL 3-4 times daily, may be adjusted as necessary to achieve 2 or 3 soft stools daily.

Adult: As 3.335 g/5 mL solution or 10 g/15 mL single dose solution sachet: Initially, 15-45 mL (10-30 g or 1-3 sachets) daily, may be adjusted according to clinical response. Maintenance dose: 15-30 mL (10-20 g or 1-2 sachets) daily. All doses may be given as single daily dose or in 2 divided doses. Therapeutic effect may occur after 2-3 days of treatment. As powder for solution:  10-20 g daily, may increase to 40 g daily if necessary.
Child: <1 year As 3.335 g/5 mL solution: Initially, up to 5 mL daily. Maintenance dose: Up to 5 mL daily. 1-6 years As 3.335 g/5 mL solution: Initially, 5-10 mL daily. Maintenance dose: 5-10 mL daily. 7-14 years As 3.335 g/5 mL solution or 10 g/15 mL single dose solution sachet: Initially, 15 mL (10 g or 1 sachet) daily, may be adjusted according to clinical response. Maintenance dose: 10-15 mL (10 g or 1 sachet) daily. >14 years Same as adult dose. All doses may be given as a single daily dose or in 2 divided doses.

Hepatic encephalopathy
Adult: Mix 200 g (300 mL) of solution with 700 mL of water or 0.9% NaCl: Administer as a retention enema via balloon catheter over 30-60 minutes, may be repeated every 4-6 hours until oral medication is possible.
May be taken with or without food. May be taken w/ meals to reduce GI discomfort. Dilute w/ water, milk, or fruit juice to improve taste.
Powder for oral solution: Dissolve contents of a packet labelled as containing 10 g or 20 g in approx 120 mL of water.
Galactosaemia, gastrointestinal obstruction or subocclusive syndromes, acute inflammatory bowel disease (e.g. ulcerative colitis, Crohn’s disease), digestive perforation or risk of digestive perforation, painful abdominal syndromes of unknown cause, low galactose diet.
Special Precautions
Patients with lactose intolerance, diabetes mellitus, gastro-cardiac syndrome (Roemheld syndrome); undergoing electrocautery procedures during proctoscopy or colonoscopy. Debilitated patients. Children (especially infants) and elderly. Pregnancy and lactation.
Adverse Reactions
Significant: Electrolyte imbalance (long-term treatment or excessive doses).
Gastrointestinal disorders: Nausea, vomiting, diarrhoea (high doses), flatulence, abdominal cramps, pain, or distension.
Metabolism and nutrition disorders: Dehydration.
Patient Counseling Information
Drink sufficient amounts of fluids (1.5-2 L or 6-8 glasses daily).
Monitoring Parameters
Monitor blood pressure, serum electrolytes, serum ammonia, fluid status and bowel movement patterns.
Symptoms: Diarrhoea, loss of electrolyte, abdominal pain. Management: Symptomatic and supportive treatment. Discontinue treatment or reduce lactulose dose. Administer fluid and electrolyte replacement as necessary for extensive fluid loss caused by diarrhoea or vomiting.
Drug Interactions
May diminish the therapeutic effect with glutamine. May increase the loss of K induced by thiazides, steroids and amphotericin B. May increase the effects of cardiac glycosides. May reduce desired effect with nonabsorbable antacids, neomycin, or other oral anti-infectives.
Description: Lactulose promotes peristalsis by producing an osmotic effect in the colon with resultant distention. In hepatic encephalopathy, it reduces absorption of ammonium ions and other toxic nitrogenous compounds, leading to reduced blood ammonia concentrations.
Onset: Constipation: Up to 24-48 hours. Hepatic encephalopathy: At least 24-48 hours.
Absorption: Poorly absorbed from the gastrointestinal tract.
Metabolism: Metabolised by colonic bacterial flora to form mainly lactic acid, and small amounts of acetic and formic acids.
Excretion: Mainly via faeces; urine (≤3% as unchanged drug).
Chemical Structure

Chemical Structure Image

Source: National Center for Biotechnology Information. PubChem Database. Lactulose, CID=11333, (accessed on Jan. 22, 2020)

Store between 15-30°C. Protect from light. Do not refrigerate or freeze.
MIMS Class
Laxatives, Purgatives
ATC Classification
A06AD11 - lactulose ; Belongs to the class of osmotically acting laxatives.
Anon. Lactulose. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. Accessed 11/07/2019.

Anon. Lactulose. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. Accessed 11/07/2019.

Buckingham R (ed). Lactulose. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. Accessed 11/07/2019.

Constulose Solution (Actavis Pharma, Inc.). DailyMed. Source: U.S. National Library of Medicine. Accessed 11/07/2019.

Kristalose Powder for Oral Solution (Cumberland Pharmaceuticals Inc.). DailyMed. Source: U.S. National Library of Medicine. Accessed 11/07/2019.

Lactulose 10 g/15 mL Oral Solution Sachets (Fresenius Kabi Austria GmbH). MHRA. Accessed 11/07/2019.

Disclaimer: This information is independently developed by MIMS based on Lactulose from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2022 MIMS. All rights reserved. Powered by
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