Laktulos Cooper
Osmotic Laxative for Constipation and Hepatic Encephalopathy
Quick Facts About Laktulos Cooper
Key Takeaways
- Laktulos Cooper is a lactulose-based osmotic laxative that treats constipation by drawing water into the bowel and softening stools.
- In hospital settings, it is also used to manage hepatic encephalopathy by reducing blood ammonia levels through acidification of the colon.
- At normal doses, lactulose does not significantly affect blood sugar levels, making it suitable for people with diabetes.
- It can be safely used during pregnancy and breastfeeding, and the onset of laxative effect typically occurs within 24–48 hours.
- Common side effects include flatulence, abdominal discomfort, and diarrhoea, which usually improve after the first few days of treatment.
What Is Laktulos Cooper and What Is It Used For?
Laktulos Cooper contains the active substance lactulose at a concentration of 670 mg/ml. Lactulose is a synthetic disaccharide — a type of sugar composed of galactose and fructose — that is not digested or absorbed in the upper gastrointestinal tract. Instead, it passes intact to the colon, where resident bacteria break it down into low-molecular-weight organic acids, primarily lactic acid, acetic acid, and formic acid.
This bacterial fermentation produces an acidic environment in the colon that has two clinically important consequences. First, the acids exert a strong osmotic effect, drawing water into the bowel lumen. This increases stool volume, softens the faeces, and stimulates colonic peristalsis, thereby relieving constipation. Unlike stimulant laxatives, lactulose works gently and does not cause dependency or irritation of the bowel wall when used as directed.
Treatment of Constipation
Constipation is an extremely common condition affecting up to 20% of the general population at any given time, according to the World Gastroenterology Organisation (WGO). Lactulose has been a first-line treatment for chronic constipation for decades and is included on the WHO Model List of Essential Medicines. It is particularly well-suited for long-term use because it does not cause electrolyte disturbances at standard doses and does not lead to colonic habituation.
For constipation relief, Laktulos Cooper is taken orally, typically once daily in the morning. It can be mixed with water, juice, or other beverages to improve palatability. The onset of action is typically 24 to 48 hours, so patients should not expect immediate results. If constipation persists after two weeks of treatment, medical advice should be sought to identify any underlying causes.
Importantly, in normal therapeutic doses for constipation, lactulose does not significantly affect blood glucose levels. This is because the compound is not absorbed from the gastrointestinal tract and is metabolised by colonic bacteria rather than by human enzymes. As a result, patients with diabetes mellitus can safely use Laktulos Cooper for constipation management.
Treatment of Hepatic Encephalopathy
Hepatic encephalopathy is a serious neuropsychiatric complication of advanced liver disease, characterised by cognitive impairment, altered consciousness, and in severe cases, coma. Ammonia is considered a key factor in the development of this condition. When the liver fails to adequately clear ammonia from the blood, elevated ammonia levels lead to cerebral oedema and astrocyte swelling, resulting in the neurological symptoms.
Lactulose addresses this problem through a dual mechanism. The acidification of the colonic environment converts ammonia (NH3) to ammonium ions (NH4+), which are poorly absorbed across the colonic mucosa. Additionally, the osmotic laxative effect increases faecal bulk and transit speed, reducing the time available for ammonia absorption. Multiple randomised controlled trials and systematic reviews, including Cochrane reviews, have confirmed that lactulose effectively reduces blood ammonia levels and improves clinical outcomes in patients with hepatic encephalopathy.
Treatment of hepatic encephalopathy with lactulose is conducted in hospital settings under close medical supervision, and doses are individually adjusted by the treating physician. The doses used for hepatic encephalopathy are typically much higher than those used for constipation.
What Should You Know Before Taking Laktulos Cooper?
Before starting treatment with Laktulos Cooper, it is important to be aware of certain medical conditions, precautions, and special populations for whom this medicine may not be appropriate or may require additional medical guidance. While lactulose is generally considered a safe and well-tolerated medicine, certain contraindications and warnings apply.
Contraindications
- You are allergic to lactulose or any other ingredient in this medicine
- You have galactosaemia — a serious genetic condition in which the body cannot break down galactose
- You have a gastrointestinal obstruction (a blockage in the stomach or intestines)
- You have or are at risk of gastrointestinal perforation (tears or holes in the digestive tract)
Galactosaemia is a rare inherited metabolic disorder in which the enzyme needed to metabolise galactose is deficient or absent. Since lactulose is broken down in the colon to release galactose among other products, individuals with galactosaemia must not use this product. The condition is typically diagnosed in infancy through newborn screening programmes.
Gastrointestinal obstruction and perforation represent surgical emergencies where the use of any osmotic laxative could worsen the condition by increasing intraluminal pressure and fluid accumulation. Patients with unexplained abdominal pain should consult a doctor before using any laxative, including lactulose.
Warnings and Precautions
Talk to your doctor before using Laktulos Cooper if you have abdominal pain of unknown origin. Unexplained abdominal pain may indicate a serious underlying condition that requires medical investigation before laxative therapy is initiated.
If you experience persistent diarrhoea during treatment, the dose should be reduced or treatment temporarily discontinued, as prolonged diarrhoea can lead to fluid loss and electrolyte imbalances, particularly hyponatraemia (low sodium) and hypokalaemia (low potassium). This is especially relevant for elderly patients and those taking medications that affect electrolyte balance, such as diuretics or corticosteroids.
Treatment of children with Laktulos Cooper should only be undertaken under the direction and supervision of a doctor. Dosages for children differ from adult doses and must be individually determined by a healthcare professional. Chronic constipation in children may have underlying causes that should be investigated.
Sugar Content
Laktulos Cooper contains up to 80 mg of lactose per ml as a by-product of the manufacturing process. The product also contains approximately 7 mg of fructose per ml. Patients with hereditary fructose intolerance — a rare genetic disorder that prevents the body from properly metabolising fructose — should consult their doctor before use. Fructose may also be harmful to teeth with prolonged use.
While standard constipation doses do not significantly affect blood sugar, the much higher doses used in the management of hepatic encephalopathy contain proportionally more lactose and may have a measurable impact on blood glucose. This should be taken into account by patients with diabetes mellitus who are receiving high-dose lactulose therapy for liver disease.
Pregnancy and Breastfeeding
Laktulos Cooper can be used during pregnancy and breastfeeding. Because lactulose is minimally absorbed from the gastrointestinal tract (less than 3% of an oral dose reaches the systemic circulation), there is negligible systemic exposure for either the mother or the infant. Lactulose is not expected to have any effect on fertility. Constipation is a common complaint during pregnancy, and lactulose is considered one of the safest laxative options for pregnant women by major obstetric guidelines, including those of the American College of Obstetricians and Gynecologists (ACOG) and the National Institute for Health and Care Excellence (NICE).
Driving and Using Machines
Laktulos Cooper has no known effects on the ability to drive or use machines. However, patients should always exercise their own judgement regarding their fitness to drive or perform tasks requiring alertness, particularly if they are experiencing side effects such as abdominal discomfort or diarrhoea.
How Does Laktulos Cooper Interact with Other Drugs?
One of the advantages of lactulose as a therapeutic agent is its favourable drug interaction profile. Because lactulose is not absorbed from the gastrointestinal tract and is metabolised exclusively by colonic bacteria, it does not undergo hepatic metabolism and does not interact with cytochrome P450 enzymes or other major drug-metabolising pathways. The manufacturer states that it is not known whether Laktulos Cooper affects or is affected by other medicines.
Nevertheless, clinicians and patients should be aware of certain theoretical considerations when using lactulose alongside other medications:
| Drug / Drug Class | Consideration | Clinical Significance |
|---|---|---|
| Antacids (e.g. aluminium, magnesium) | May neutralise the acid produced by lactulose fermentation, potentially reducing efficacy | Low — unlikely at standard doses |
| Mesalazine (5-ASA) | Lactulose may lower colonic pH, potentially affecting the release of pH-dependent mesalazine formulations | Low — monitor response |
| Neomycin / other antibiotics | Antibiotics may destroy colonic bacteria needed to break down lactulose, reducing its efficacy | Moderate — in hepatic encephalopathy, combination is sometimes used intentionally |
| Diuretics (e.g. furosemide) | Combined risk of electrolyte depletion if lactulose causes significant diarrhoea | Moderate — monitor electrolytes |
| Cardiac glycosides (e.g. digoxin) | Electrolyte disturbances from prolonged diarrhoea (especially hypokalaemia) may enhance cardiac glycoside toxicity | Moderate — monitor potassium levels |
It is always good practice to inform your doctor or pharmacist about all medicines you are currently taking, have recently taken, or might take in the future. Although lactulose has no established drug interactions, comprehensive medication review helps ensure optimal therapeutic outcomes and patient safety.
Patients who are receiving lactulose for hepatic encephalopathy in hospital settings should be particularly aware that the combination of lactulose with certain antibiotics such as neomycin or rifaximin is sometimes used deliberately as part of the treatment regimen. In this context, the potential reduction in lactulose efficacy from antibiotic-mediated destruction of colonic flora is weighed against the complementary ammonia-lowering effects of the antibiotic.
What Is the Correct Dosage of Laktulos Cooper?
Always take Laktulos Cooper exactly as described in the patient information leaflet or as directed by your doctor or pharmacist. If you are unsure about the correct dose, ask your doctor or pharmacist for advice. The dosage varies depending on the condition being treated and the patient population.
Adults — Constipation
Standard Adult Dosage for Constipation
- Initial dose: 30 ml once daily for 2–4 days
- Maintenance dose: 10–25 ml once daily
- Administration: Take the full daily dose in the morning, preferably mixed with water, juice, chocolate milk, yoghurt, or porridge
- Duration: Consult your doctor if symptoms do not improve within 2 weeks
The goal of maintenance therapy is to achieve one to two soft stools per day. The dose should be gradually reduced once regular bowel movements are established. Many patients find that a daily maintenance dose of 10–15 ml is sufficient for ongoing constipation management. The entire daily dose should ideally be taken at the same time each day, preferably in the morning, to establish a predictable bowel routine.
For chronic or recurrent constipation, patients should consult their doctor rather than continuing to self-medicate indefinitely. Chronic constipation may be a symptom of an underlying condition that requires specific investigation and treatment. Healthcare providers may recommend dietary and lifestyle modifications alongside lactulose therapy, including increased fibre intake, adequate hydration, and regular physical activity.
Children
Treatment of children with Laktulos Cooper should only be initiated by a doctor. The dosage for paediatric patients varies according to age and weight and must be individually determined by a healthcare professional. Do not give this medicine to children without medical advice.
Lactulose is widely used in paediatric gastroenterology for the management of functional constipation in children. International guidelines, including those from the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN), recognise lactulose as an effective and safe option for childhood constipation. However, proper medical assessment is essential to exclude organic causes of constipation in children before initiating treatment.
Elderly
No specific dose adjustment is required for elderly patients. However, elderly individuals are more susceptible to dehydration and electrolyte imbalances, particularly if lactulose causes significant diarrhoea. Adequate fluid intake should be maintained throughout treatment. Healthcare providers should monitor electrolyte levels periodically in elderly patients on long-term lactulose therapy, especially those concurrently taking diuretics or other medications that affect fluid and electrolyte balance.
Hepatic Encephalopathy (Hospital Use)
Hepatic Encephalopathy Dosage
- Dosage: Individually determined by the treating physician
- Goal: 2–3 soft stools per day
- Setting: Hospital use with medical supervision
- Monitoring: Regular assessment of blood ammonia levels, mental status, and electrolytes
Doses for hepatic encephalopathy are typically much higher than constipation doses and may range from 30–50 ml three times daily, adjusted according to clinical response. The target is usually two to three soft stools per day. In acute hepatic encephalopathy, lactulose may also be administered rectally as a retention enema. Treatment should be closely monitored by the medical team, with regular assessment of neurological status, blood ammonia levels, and serum electrolytes.
Missed Dose
If you forget to take your dose of Laktulos Cooper, simply take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to compensate for a missed dose. Missing a single dose of lactulose is unlikely to cause any significant clinical consequences.
Overdose
If you have taken too much Laktulos Cooper, or if a child has accidentally consumed the medicine, contact your doctor, hospital, or poison control centre immediately. Symptoms of overdose may include abdominal pain and diarrhoea. Severe diarrhoea can lead to dehydration and electrolyte imbalances that may require medical management.
What Are the Side Effects of Laktulos Cooper?
Like all medicines, Laktulos Cooper can cause side effects, although not everybody gets them. Most side effects of lactulose are related to its action in the gastrointestinal tract and are typically mild and self-limiting. Side effects are more common at the start of treatment and tend to diminish as the body adjusts to the medicine.
The frequency categories below are defined according to internationally accepted conventions: very common (affects more than 1 in 10 people), common (affects 1 in 10 to 1 in 100 people), uncommon (affects 1 in 100 to 1 in 1,000 people), rare (affects fewer than 1 in 1,000 people), and not known (frequency cannot be estimated from available data).
Common
- Flatulence (gas) — typically improves after a few days
- Abdominal pain or cramping
- Nausea
- Diarrhoea (indicates dose may need reducing)
- Elevated blood sodium levels (hypernatraemia) — reported in patients with severe liver disease
Uncommon
- Electrolyte imbalance caused by persistent diarrhoea (including hypokalaemia and hyponatraemia)
Rare
- Skin rash (primarily reported in patients with severe liver disease)
Not Known
- Allergic reactions
- Rash, itching, or hives (urticaria)
Flatulence is the most frequently reported side effect of lactulose and is a direct consequence of its mechanism of action: bacterial fermentation of lactulose in the colon produces gases including hydrogen, methane, and carbon dioxide. This effect is usually most pronounced during the first few days of treatment and typically diminishes as the colonic flora adapts to the presence of the substrate.
Diarrhoea during lactulose therapy is a sign that the dose is too high and should be reduced. Prolonged or severe diarrhoea can lead to clinically significant fluid and electrolyte losses, particularly potassium and sodium. This is especially important in elderly patients, patients taking diuretics, and patients with hepatic encephalopathy who are receiving high-dose therapy. Regular monitoring of serum electrolytes is recommended in these populations.
If you experience any side effects that are bothersome or persistent, or if you notice symptoms not listed here, please contact your doctor or pharmacist. Reporting suspected adverse reactions after a medicine has been authorised is important, as it allows continuous monitoring of the medicine's benefit-risk balance.
How Should You Store Laktulos Cooper?
Proper storage of medicines is essential to maintain their effectiveness and safety. Laktulos Cooper should be stored out of the sight and reach of children at all times. The medicine should not be used after the expiry date stated on the label after “EXP”. The expiry date refers to the last day of the stated month.
Laktulos Cooper is a clear to slightly opalescent, colourless oral solution. If the solution appears significantly discoloured, cloudy, or contains particulate matter, it should not be used. No special storage temperature conditions are required for this product, although it should be protected from excessive heat and direct sunlight.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines that are no longer needed. These measures help protect the environment and prevent accidental exposure. Many communities offer take-back programmes or designated disposal facilities for unused or expired medicines.
Available Package Sizes
Laktulos Cooper is available in the following package sizes:
- Plastic bottles: 200 ml, 500 ml, and 1,000 ml
- Plastic container: 5,000 ml (prescription only — for hospital and institutional use)
Not all package sizes may be marketed in all countries.
What Does Laktulos Cooper Contain?
Laktulos Cooper has a simple and straightforward composition. The active substance is liquid lactulose, with each millilitre of oral solution containing 670 mg of liquid lactulose. The only excipient (inactive ingredient) is purified water.
As a by-product of the manufacturing process, each millilitre of solution contains up to 80 mg of lactose. This is an important consideration for patients with lactose intolerance, although the quantities are small enough that most lactose-intolerant individuals tolerate standard constipation doses without difficulty. The product also contains approximately 7 mg of fructose per ml.
| Component | Amount per ml | Role |
|---|---|---|
| Liquid Lactulose | 670 mg | Active ingredient |
| Purified Water | q.s. to 1 ml | Solvent (excipient) |
| Lactose (from manufacturing) | ≤ 80 mg | Manufacturing by-product |
| Fructose (trace) | ~7 mg | Manufacturing by-product |
The marketing authorisation holder for Laktulos Cooper is Cooper Consumer Health B.V., based in Diemen, the Netherlands. The product is manufactured by Unimedic AB (Matfors, Sweden) and Fresenius Kabi Austria GmbH (Linz, Austria).
Frequently Asked Questions About Laktulos Cooper
Laktulos Cooper is an oral lactulose solution used primarily to treat constipation. It works by drawing water into the bowel, softening stools, and promoting regular bowel movements. In hospital settings, it is also used to manage hepatic encephalopathy (a complication of severe liver disease) by reducing elevated ammonia levels in the blood. At normal constipation doses, it does not affect blood sugar and can be used by people with diabetes.
Lactulose typically begins working within 24 to 48 hours after the first dose. It is not an instant-acting laxative. For optimal results, take it consistently every day at the same time, preferably in the morning. If you do not see improvement within two weeks, consult your doctor.
Yes, Laktulos Cooper can be safely used during pregnancy and breastfeeding. Lactulose is minimally absorbed from the gastrointestinal tract, so systemic exposure is negligible. It is considered one of the safest laxative options during pregnancy by major international obstetric guidelines, including those of ACOG and NICE. However, always inform your healthcare provider about all medicines you are taking during pregnancy.
The most common side effects of Laktulos Cooper include flatulence (gas), abdominal pain or cramping, nausea, and diarrhoea. These symptoms are usually mild and tend to subside within the first few days of treatment. If diarrhoea occurs, it usually means the dose is too high and should be reduced. If side effects persist or become severe, contact your doctor.
At normal doses used for constipation, lactulose does not significantly affect blood sugar levels and is considered safe for people with diabetes. This is because lactulose is not absorbed from the gastrointestinal tract and is metabolised by colonic bacteria rather than by human enzymes. However, the higher doses used for hepatic encephalopathy contain more residual sugars (including lactose) and may need to be considered by patients with diabetes mellitus.
Lactulose can be used in children, but treatment should only be started and supervised by a doctor. The dosage for children is different from adult dosing and must be individually determined based on age, weight, and the severity of constipation. Never administer lactulose to a child without first consulting a healthcare professional.
References
All information is based on international medical guidelines and peer-reviewed research. Evidence level: 1A.
- World Health Organization (WHO). WHO Model List of Essential Medicines — 23rd List. Geneva: WHO; 2023.
- World Gastroenterology Organisation (WGO). WGO Global Guidelines: Constipation — A Global Perspective. Milwaukee: WGO; 2023.
- European Association for the Study of the Liver (EASL). EASL Clinical Practice Guidelines on the Management of Hepatic Encephalopathy. J Hepatol. 2022;77(3):807–824.
- Gluud LL, Vilstrup H, Morgan MY. Non-absorbable disaccharides versus placebo/no intervention and lactulose versus lactitol for the prevention and treatment of hepatic encephalopathy in people with cirrhosis. Cochrane Database Syst Rev. 2016;(5):CD003044.
- National Institute for Health and Care Excellence (NICE). Constipation in children and young people: diagnosis and management. NICE Guideline CG99. London: NICE; 2017 (updated 2023).
- Tabbers MM, DiLorenzo C, Berger MY, et al. Evaluation and treatment of functional constipation in infants and children: evidence-based recommendations from ESPGHAN and NASPGHAN. J Pediatr Gastroenterol Nutr. 2014;58(2):258–274.
- American College of Obstetricians and Gynecologists (ACOG). Practice Bulletin: Constipation During Pregnancy. Obstet Gynecol. 2023.
- British National Formulary (BNF). Lactulose. London: BMJ Group and Pharmaceutical Press; 2026.
- European Medicines Agency (EMA). Summary of Product Characteristics: Lactulose. Amsterdam: EMA; 2025.
Medical Editorial Team
All content on iMedic is written, reviewed, and fact-checked by licensed medical professionals. Our editorial standards follow the GRADE evidence framework and adhere to international medical guidelines.
Medical Writers
Specialist physicians in gastroenterology and clinical pharmacology
Medical Reviewers
Independent review board following WHO, WGO, and EASL guidelines
Evidence Level
Grade 1A — systematic reviews and meta-analyses of RCTs
Funding
No commercial funding. Independent medical editorial content.