Laktulos Levolac

What Is Laktulos Levolac and What Is It Used For?

Laktulos Levolac contains the osmotic laxative lactulose (670 mg/ml). It draws water into the bowel, softening stools and stimulating bowel movements. It is primarily used to treat constipation and can also be prescribed for hepatic encephalopathy, a serious liver condition affecting brain function.

Lactulose is a synthetic disaccharide composed of the sugars galactose and fructose. Unlike natural sugars such as lactose or sucrose, lactulose cannot be broken down by the enzymes in the human small intestine. This means it passes through the stomach and small intestine completely unchanged until it reaches the large bowel (colon). Here, the resident bacteria – particularly Lactobacillus and Bacteroides species – ferment lactulose into low-molecular-weight organic acids, primarily lactic acid, acetic acid, and formic acid.

This bacterial fermentation has two important consequences. First, it lowers the pH (increases acidity) within the colon, creating an osmotic gradient that draws water from the surrounding tissues into the intestinal lumen. The increased water content softens the stool and increases its bulk, which stimulates the natural muscular contractions of the bowel (peristalsis) and makes passing stools significantly easier. Second, the acidification of colonic contents promotes the growth of beneficial bacteria while suppressing the growth of potentially harmful organisms, giving lactulose a prebiotic effect.

For the treatment of constipation, lactulose is one of the most widely recommended osmotic laxatives worldwide. The World Gastroenterology Organisation (WGO) and the American Gastroenterological Association (AGA) include lactulose in their clinical guidelines as a first-line treatment for chronic functional constipation. It is suitable for adults, and, under medical supervision, can be used in children, elderly patients, and pregnant women.

In the treatment of hepatic encephalopathy (also known as portal-systemic encephalopathy or hepatic coma), lactulose plays a different but equally important role. In patients with severe liver disease, the liver cannot adequately filter ammonia and other toxins from the blood. These toxins accumulate and cross the blood-brain barrier, causing confusion, disorientation, drowsiness, and in severe cases, coma. Lactulose helps by acidifying the colonic contents, which converts ammonia (NH₃) into ammonium ions (NH₄⁺). Ammonium ions are charged particles that cannot be reabsorbed through the intestinal wall back into the bloodstream. They are then eliminated in the faeces, effectively reducing blood ammonia levels and improving neurological symptoms.

What Should You Know Before Taking Laktulos Levolac?

Before taking Laktulos Levolac, you should be aware of certain conditions that prevent its use, including galactosaemia, acute inflammatory bowel disease, and intestinal obstruction. Patients with diabetes should note that lactulose contains trace sugars. Always drink adequate fluids during treatment.

Contraindications

You should not take Laktulos Levolac if any of the following apply to you:

• Allergy to lactulose or any other ingredient in this medicine – although allergic reactions to lactulose are extremely rare, stop use and seek medical attention if you develop rash, itching, or difficulty breathing
• Galactosaemia – a rare inherited metabolic disorder in which the body cannot break down galactose. Since lactulose is broken down into galactose and fructose in the colon, patients with galactosaemia must not take this medicine
• Acute inflammatory bowel disease – including Crohn's disease and ulcerative colitis in active flare. The osmotic effect of lactulose may worsen symptoms such as diarrhoea, abdominal pain, and intestinal inflammation
• Intestinal obstruction (ileus) – except for normal constipation, any mechanical or functional blockage of the bowel requires immediate medical evaluation and not laxative treatment
• Perforation or risk of perforation of the digestive tract – any condition that weakens the intestinal wall makes laxative use dangerous
• Unexplained abdominal pain – taking a laxative when the cause of abdominal pain is unknown can mask serious underlying conditions and delay necessary treatment

Warnings and Precautions

Talk to your doctor or pharmacist before taking Laktulos Levolac if you have any of the following conditions:

Roemheld syndrome (gastric-cardiac syndrome): If you suffer from a gastrointestinal disorder accompanied by cardiac dysfunction, inform your doctor before starting treatment. Lactulose can cause gas production in the colon, which may trigger symptoms such as bloating, abdominal distension, and cardiac discomfort. If these symptoms occur, stop taking lactulose and consult your doctor immediately.

Long-term use and electrolyte monitoring: Prolonged use of unadjusted doses – particularly doses that cause more than 2–3 bowel movements per day – can lead to diarrhoea and a disturbance in the body's electrolyte balance, especially low potassium (hypokalaemia). Low potassium can cause muscle weakness, cramps, irregular heartbeat, and fatigue. If you are elderly or in poor general health and take lactulose for longer than 6 months, your doctor should regularly check your blood electrolyte levels.

Patients with hepatic encephalopathy: If you are taking lactulose for liver-related brain dysfunction, you should avoid using other laxatives at the same time. Combining laxatives makes it very difficult for your doctor to determine the correct individual dose of lactulose, and the risk of diarrhoea and electrolyte disturbance increases significantly.

Duration of self-treatment: Do not use Laktulos Levolac for more than two weeks without consulting a doctor. Constipation lasting longer than two weeks may be a sign of an underlying medical condition that requires investigation, such as hypothyroidism, colorectal disease, or medication side effects.

Sugar content: Laktulos Levolac may contain trace amounts of sugars (lactose, galactose, and epilactose) that are formed during the manufacturing process. If your doctor has told you that you have an intolerance to certain sugars, consult your doctor before taking this medicine. Each 15 ml dose of Laktulos Levolac contains approximately 42.7 kJ (10.2 kcal), which should be taken into consideration by patients with diabetes when determining the dosage.

Adequate fluid intake: During treatment with any laxative, it is essential to drink sufficient fluids – approximately 2 litres per day (equivalent to 6–8 glasses). Inadequate fluid intake can reduce the effectiveness of lactulose and may lead to dehydration, particularly in elderly patients or those taking diuretics.

Use in Children

Laktulos Levolac should not normally be given to infants and young children, as it may interfere with the development of normal bowel movement reflexes. In infants and toddlers, the habitual use of laxatives can prevent the child from learning to recognise and respond to natural urges to have a bowel movement. However, in special circumstances, a doctor may prescribe lactulose for children, infants, or even newborns – for example, in cases of severe constipation that has not responded to dietary measures. In all such cases, the treatment should be under careful medical supervision with regular reassessment of the need for continued therapy.

Pregnancy and Breastfeeding

Lactulose is generally considered safe during pregnancy and breastfeeding. Because it is not absorbed from the gastrointestinal tract, lactulose does not enter the maternal bloodstream and therefore cannot cross the placenta or pass into breast milk. The American College of Obstetricians and Gynecologists (ACOG) and the National Institute for Health and Care Excellence (NICE) both list osmotic laxatives, including lactulose, among the first-line options for treating constipation in pregnancy. Constipation is very common during pregnancy due to hormonal changes (particularly elevated progesterone levels) and iron supplementation.

Nevertheless, as a general precaution, you should always inform your doctor, midwife, or pharmacist before starting any new medication during pregnancy or while breastfeeding, to ensure it is appropriate for your individual situation.

Driving and Operating Machinery

Laktulos Levolac does not affect the ability to drive or operate machinery. It has no sedating, stimulating, or otherwise impairing effects on the central nervous system. You can safely drive, operate heavy machinery, and carry out tasks requiring concentration while taking this medicine.

Taking with Food and Drink

Laktulos Levolac can be taken with or without food. The oral solution can be taken undiluted or mixed with a small amount of liquid such as water, juice, or milk. There are no dietary restrictions while taking lactulose. Many people find it easiest to take their daily dose mixed into a drink at breakfast time.

How Does Laktulos Levolac Interact with Other Drugs?

Lactulose has relatively few drug interactions because it is not absorbed into the bloodstream. However, it can enhance potassium loss caused by certain medications (diuretics, corticosteroids, amphotericin B) and may affect the release of pH-dependent colon drugs such as mesalazine. Always inform your doctor about all medications you are taking.

Because lactulose acts exclusively within the colon and is not absorbed systemically, it has far fewer drug interactions than most other medications. However, there are several clinically important interactions to be aware of, particularly when lactulose is used at higher doses or for extended periods.

Interactions Affecting Potassium Balance

The most clinically significant interactions involve medications that also affect potassium levels. Lactulose, particularly at higher doses or when causing diarrhoea, can increase the loss of potassium from the body through the stool. When combined with other drugs that lower potassium, the cumulative effect can lead to hypokalaemia (dangerously low potassium), which can cause muscle weakness, cardiac arrhythmias, and in severe cases, cardiac arrest.

Interactions with Cardiac Glycosides

Cardiac glycosides such as digoxin are used to treat heart failure and certain heart rhythm disorders. Low potassium levels make the heart more sensitive to the effects of digoxin, significantly increasing the risk of serious and potentially life-threatening side effects, including dangerous cardiac arrhythmias. If you are taking digoxin and lactulose together, your doctor should monitor your potassium levels regularly and ensure that lactulose is not causing diarrhoea, which would accelerate potassium loss.

Interactions with pH-Dependent Colon Drugs

At higher doses, lactulose significantly lowers the pH in the colon. Some medications are specifically designed to be released in the colon at a particular pH level. The most clinically relevant example is 5-aminosalicylic acid (5-ASA) preparations such as mesalazine (mesalamine), which are used to treat inflammatory bowel disease. The lower pH caused by lactulose may prevent these medications from being properly released, reducing their effectiveness. If you are taking 5-ASA preparations for Crohn's disease or ulcerative colitis, discuss with your doctor whether lactulose is appropriate for you.

Overall, lactulose is considered to have a very favourable interaction profile. Because it is not absorbed and does not undergo hepatic metabolism, it does not interact with the cytochrome P450 enzyme system. This means it is safe to use alongside the vast majority of medications. However, always inform your doctor, pharmacist, or other healthcare provider about all medicines you are currently taking, including over-the-counter products and herbal supplements.

What Is the Correct Dosage of Laktulos Levolac?

For constipation in adults, the usual starting dose is 15–45 ml daily, which is then reduced to a maintenance dose of 15–30 ml daily. Take your dose at the same time each day, preferably with breakfast. Use the measuring cup provided. The full effect may take 2–3 days to develop.

Always take Laktulos Levolac exactly as your doctor or pharmacist has instructed. If you are self-treating constipation, follow the dosage guidelines on the packaging. If in doubt, consult your doctor or pharmacist. Take your dose at the same time each day for consistent results. The dose can be taken once daily (for example at breakfast) or divided into up to three doses throughout the day.

Swallow the medicine in one gulp – it should not be held in the mouth. You can take the oral solution undiluted or mixed with a small amount of water, juice, or another beverage. Use the measuring cup (graduated in ml) provided with each bottle.

Adults and Adolescents Over 14 Years – Constipation

It is important to understand that lactulose does not work immediately. Because it must first reach the colon and be broken down by bacteria, the full laxative effect typically takes 2–3 days to develop. Do not increase your dose during this initial period unless instructed by your doctor. If constipation persists after several days of consistent use at the recommended dose, consult a healthcare professional.

Hepatic Encephalopathy (Prescribed by Doctor Only)

Children (Under Medical Supervision Only)

The safety and efficacy of lactulose in children aged 0–18 years have not been fully established in large clinical trials. Treatment of children with lactulose should only occur after it has been prescribed by a doctor, and the dose will be determined individually based on the child's age, weight, and clinical response. Your child's doctor will carefully monitor the treatment and regularly reassess whether continued use is necessary.

Elderly Patients

There are no specific dosage adjustments recommended for elderly patients. However, older adults are more susceptible to dehydration and electrolyte disturbances. If you are elderly and taking lactulose for more than 6 months, your doctor should periodically check your blood electrolyte levels (particularly potassium, sodium, and chloride). Ensure you maintain adequate fluid intake throughout treatment.

Missed Dose

If you forget to take a dose, simply take your next dose at the usual time. Do not take a double dose to make up for the missed one. Missing a single dose of lactulose is unlikely to have any noticeable effect on your constipation treatment, as the medicine works gradually over days rather than hours.

Overdose

Stopping Laktulos Levolac

You can generally stop taking lactulose for constipation without any specific tapering schedule, as it does not cause dependency or withdrawal effects. However, the underlying constipation may return when you stop. If you have been taking lactulose for hepatic encephalopathy, do not stop without consulting your doctor, as sudden discontinuation can lead to a dangerous rise in blood ammonia levels and worsening of neurological symptoms.

What Are the Side Effects of Laktulos Levolac?

The most common side effects of lactulose are flatulence (gas) and bloating, which typically occur during the first few days and usually resolve on their own. Excessive doses may cause abdominal pain, nausea, vomiting, and diarrhoea. Rare allergic reactions have been reported.

Like all medicines, Laktulos Levolac can cause side effects, although not everybody gets them. Most side effects are mild, dose-dependent, and tend to resolve with continued use or dose adjustment. The bacterial fermentation of lactulose in the colon naturally produces gas, which is the primary cause of the most common side effects.

The flatulence experienced during the first few days of treatment is a natural consequence of bacterial fermentation of lactulose in the colon and is not a cause for concern. This side effect typically diminishes significantly after the first 2–3 days of regular use as the colonic bacteria adapt. Starting with a lower dose and gradually increasing to the target dose can help minimise this initial gassiness.

If you experience diarrhoea, this is usually a sign that the dose is too high. Simply reduce the dose until you achieve the desired stool consistency (soft but formed stools, 1–2 bowel movements per day). Persistent diarrhoea should be reported to your doctor, as it can lead to dehydration and electrolyte disturbances, particularly in elderly patients, children, and those taking diuretics or cardiac glycosides.

How Should You Store Laktulos Levolac?

Store Laktulos Levolac at a temperature below 25°C (77°F). Keep the bottle tightly closed after each use. Once opened, the solution can be used for up to 1 year. Always check the expiry date and keep the medicine out of the reach of children.

Proper storage of medicines is important to maintain their effectiveness and safety throughout their shelf life. Follow these guidelines for Laktulos Levolac:

• Temperature: Store at or below 25°C (77°F). Do not freeze. Lactulose solution is stable at room temperature but should be protected from excessive heat.
• Container: Keep the bottle tightly closed after each use to prevent contamination and evaporation. The solution is supplied in brown glass or brown/white plastic bottles with screw caps or child-resistant closures.
• Shelf life after opening: Once opened, Laktulos Levolac can be used for up to 1 year, provided it is stored correctly and the expiry date on the label has not passed.
• Expiry date: Do not use Laktulos Levolac after the expiry date stated on the bottle label and/or outer packaging. The expiry date refers to the last day of the stated month.
• Keep out of reach: Store this medicine out of the sight and reach of children.
• Disposal: Do not dispose of medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines you no longer need. These measures help protect the environment.

Laktulos Levolac oral solution is a clear, viscous, colourless to slightly brownish-yellow liquid. Minor colour variation is normal and does not indicate a problem with the medicine. However, if you notice any unusual changes in colour, consistency, or odour, do not use the product and consult your pharmacist.

What Does Laktulos Levolac Contain?

Laktulos Levolac contains only one ingredient: lactulose (as liquid lactulose) at a concentration of 670 mg per ml. There are no other additives, preservatives, sweeteners, or inactive ingredients in this formulation.

The simplicity of this formulation is one of its advantages. Each millilitre of Laktulos Levolac oral solution contains 670 mg of lactulose (as liquid lactulose). There are no other ingredients. This single-ingredient formulation minimises the risk of allergic reactions and interactions related to excipients.

Lactulose is a synthetic disaccharide composed of one molecule of galactose and one molecule of fructose linked by a beta-1,4-glycosidic bond. This particular bond cannot be cleaved by human digestive enzymes (which are specific for alpha-glycosidic bonds), which is why lactulose passes through the upper gastrointestinal tract unchanged. Only the bacteria in the colon possess the beta-galactosidase enzymes necessary to break down lactulose.

Available package sizes: Laktulos Levolac is available in brown glass bottles and brown or white plastic bottles containing 100 ml, 200 ml, 250 ml, 300 ml, 500 ml, 1000 ml, and multipacks of 10 × 100 ml. Each bottle comes with a polypropylene measuring cup with graduated markings for accurate dosing. Not all package sizes may be marketed in every country.

Manufacturer: Laktulos Levolac is manufactured by Fresenius Kabi Austria GmbH, a global healthcare company specialising in pharmaceutical products for nutrition, infusion therapy, and clinical care.