This information is intended for use by health professionals

1. Name of the medicinal product


2. Qualitative and quantitative composition

Active ingredient:

Lactulose Solution BP 99.897% v/v.

(Equivalent to 62.0 - 74.0% w/v of Lactulose).

3. Pharmaceutical form

Oral solution.

4. Clinical particulars
4.1 Therapeutic indications

Constipation; hepatic encephalopathy (portal systemic encephalopathy).

4.2 Posology and method of administration

For oral administration.

The lactulose solution may be administered diluted or undiluted. Each dose may, if necessary, be taken with water or fruit juices etc.

Each dose of lactulose should be swallowed in one and should not be kept in the mouth for an extended period of time.

All dosages should be adjusted to the needs of the individual.

In case of single daily dose, this should be taken at the same time, e.g. during breakfast.

During the therapy with laxatives it is recommended to drink sufficient amounts of fluids (1.5-2 litres, equal to 6-8 glasses) during the day.

Dosing in constipation:

Lactulose may be given as a single daily dose or in two divided doses.

After a few days the starting dosage may be adjusted to the maintenance dose based upon treatment response. Several days (2-3 days) of treatment may be needed before treatment effect occurs.

Starting dose daily

Maintenance dose daily

Adults and adolescents

15-45 ml

15-30 ml


(7-14 years)

15 ml

10-15 ml


(1-6 years)

5-10 ml

5-10 ml

Infants under 1 year

Up to 5 ml

Up to 5 ml

Dosing in Hepatic Encephalopathy (for adults only):

Starting dose: 3 to 4 times daily 30-45ml (6-9 x 5ml spoonfuls). This dose may be adjusted to the maintenance dose to achieve two or three soft stools each day.

Paediatric population:

The safety and efficacy in children (newborn to 18 years of age) with Hepatic Encephalopathy have not been established. No data are available.

Elderly patients and patients with renal or hepatic insufficiency:

No special dosage recommendations exist, since systemic exposure to lactulose is negligible.

4.3 Contraindications

Lactugal is contra-indicated in patients with:

• Galactosaemia

• Gastro-intestinal obstruction, digestive perforation or risk of digestive perforation

• Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

4.4 Special warnings and precautions for use

Consultation of a physician is advised in case of:

- Painful abdominal symptoms of undetermined cause before the treatment is started.

- Insufficient therapeutic effect after several days.

Lactulose should be administered with care to patients who are intolerant to lactose (see section 'List of excipients'). The dose normally used in constipation should not pose a problem for diabetics.

The dose used in the treatment of hepatic encephalopathy is usually much higher and may need to be taken into consideration for diabetics.

Chronic use of unadjusted doses and misuse can lead to diarrhoea and disturbance of the electrolyte balance.

This product contains lactose, galactose and small amounts of fructose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Paediatric population

Use of laxatives in children should be exceptional and under medical supervision.

It should be taken into account that the defaecation reflex could be disturbed during the treatment.

4.5 Interaction with other medicinal products and other forms of interaction

No interaction studies have been performed.

4.6 Fertility, pregnancy and lactation


No effects during pregnancy are anticipated, since systemic exposure to lactulose is negligible.

Lactulose can be used during pregnancy.


No effects on the breastfed newborn/infant are anticipated since the systemic exposure of the breast-feeding woman to lactulose is negligible.

Lactugal can be used during breast feeding.


No effects are to be expected, since systemic exposure to lactulose is negligible.

4.7 Effects on ability to drive and use machines

Lactulose has no or negligible influence on the ability to drive and use machines.

4.8 Undesirable effects

A normal dosage of lactulose may cause mild abdominal pain and flatulence which will disappear spontaneously after a few days. High doses may provoke nausea in some patients and this can be minimised by administration with water, fruit juice or meals. Administration of higher doses than those instructed can result in abdominal pain and diarrhoea, in this instance the dose should be decreased (see also section 4.9).

If high doses (such as those associated with the treatment of portosystemic encephalopathy) are used for extended periods of time, the patient may experience an electrolyte imbalance due to diarrhoea. The dose should be adjusted to obtain two to three formed stools per day.

Tabulated list of adverse events

The following undesirable effects have been experienced with the below indicated frequencies in lactulose-treated patients:

very common (≥1/10);

common (≥1/100 to <1/10);

uncommon (≥1/1,000 to <1/100)

rare (≥1/10,000 to <1/1,000)

very rare (<1/10,000)


Frequency category

Very common




Gastrointestinal disorders


Flatulence, abdominal pain, nausea, vomiting


Electrolyte imbalance due to diarrhoea

Paediatric population

The safety profile in children is expected to be similar as in adults.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product.

Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at:

or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9 Overdose

If the dose is too high, the following may occur: diarrhoea and abdominal pain

Treatment: A dose reduction or cessation of therapy should be considered. Excessive fluid loss due to diarrhoea or vomiting may result in clinically important electrolyte disturbances, and suitable corrective measures should be taken.

There is no specific antidote and supportive, symptomatic treatment should be given.

5. Pharmacological properties
5.1 Pharmacodynamic properties

Pharmacotherapeutic group: Osmotically acting laxatives, ATC code: A 06A D11

Lactulose is a synthetic disaccharide which is metabolised by gastro-intestinal bacterial flora to low molecular weight acids (chiefly lactic and acetic acids). There is no endogenous metabolising enzyme in the human gut.

Its mode of action in constipation is as an osmotic agent producing soft stools.

In the colon lactulose is broken down by colonic bacteria into low molecular organic acids. These acids lead to a lowering of pH in the colonic lumen and via an osmotic effect to an increase of the volume of colonic contents. These effects stimulate peristalsis of the colon and return the consistency of the stool. The constipation is cleared and the physiological rhythm of the colon is reinstated.

In hepatic encephalopathy (HE) the effect has been attributed to suppression of proteolytic bacteria by an increase of acidophilic bacteria (e.g. lactobacillus), trapping of ammonia in the ionic form by acidification of the colonic contents, catharsis due to the low pH in the colon as well as an osmotic effect, and alteration of the bacterial nitrogen metabolism by stimulating the bacteria to utilize ammonia for bacterial protein synthesis.

5.2 Pharmacokinetic properties

Lactulose is poorly absorbed from the gastro-intestinal tract and it reaches the colon unchanged.

There are no human lactulose disaccharide enzymes; metabolism of lactulose to lactic acid occurs via gastro-intestinal microbial flora only. Due to its poor bioavailability, plasma lactulose concentrations are negligible.

Metabolism is complete at doses up to 25-50 g or 40-75 ml; at higher dosages, a proportion may be excreted unchanged.

There are no known changes in kinetic properties in patients with organic diseases which may alter drug disposition

5.3 Preclinical safety data

The results of acute, sub-chronic and chronic toxicity studies in various species indicate that the compound has very low toxicity. The effects observed, appear to be more related to the effect of bulk in the gastrointestinal tract than to a more specific toxic activity. In reproduction and teratology experiments in rabbits, rats or mice, no adverse effects were found.

6. Pharmaceutical particulars
6.1 List of excipients

Banana flavour (17.41.0042)

Quinoline yellow (E104)

6.2 Incompatibilities

There are no known incompatibilities.

6.3 Shelf life

36 months from the date of manufacture.

6.4 Special precautions for storage

Store at a temperature not exceeding 20°C. Do not freeze.

6.5 Nature and contents of container

Amber glass winchesters with polypropylene caps as closures: pack sizes 300 ml, 500 ml, 1000 ml and 2000 ml.

Polyethylene containers with polypropylene caps as closures: pack sizes 250 ml, 300 ml, 500 ml, 1000 ml and 2000 ml.

Not all pack sizes may be marketed.

6.6 Special precautions for disposal and other handling

There are no special storage or handling instructions for this product.

7. Marketing authorisation holder

Intrapharm Laboratories Ltd

The Courtyard Barns

Choke Lane


Berkshire SL6 6PT

United Kingdom

8. Marketing authorisation number(s)

PL 17509/0011

9. Date of first authorisation/renewal of the authorisation

24 November 2004

10. Date of revision of the text

28th February 2018