This information is intended for use by health professionals

1. Name of the medicinal product

Lactulose 3.3g/5ml Oral Solution

2. Qualitative and quantitative composition

1ml contains 670 mg Lactulose (as lactulose liquid).

For the full list of excipients, see section 6.1.

3. Pharmaceutical form

Oral solution

Clear colourless to pale brownish yellow, viscous solution

4. Clinical particulars
4.1 Therapeutic indications

Symptomatic treatment of Constipation

4.2 Posology and method of administration

The lactulose solution may be administered diluted or undiluted. The dose should be titrated according to the clinical response. Lactulose may be given as a single daily dose or in two divided doses, using the measuring cup.

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

The posology should be adjusted according to the individual needs of the patient. The starting dose can be adjusted after adequate treatment effect individually (maintenance dose). Several days (2-3 days) of treatment may be needed in some patients before adequate treatment effect occurs. In case of single daily dose, this should be taken at the same time of the day, e.g. during breakfast. During the therapy with laxatives it is recommended to drink sufficient amounts of fluids (1.5-2 l/day, equal to 6-8 glasses).


Starting dose (per day)

Maintenance dose (per day)

Adults and adolescents over 14 years

15-45 ml

corresponding to 10-30 g lactulose

15-30 ml

corresponding to 10-20 g lactulose


(7-14 years)

15 ml

corresponding to 10 g lactulose

10-15 ml

corresponding to 7-10 g lactulose


(1-6 years)

5-10 ml

corresponding to 3-7 g lactulose

5-10 ml

corresponding to 3-7 g lactulose


up to 5 ml

corresponding to up to 3 g lactulose

up to 5 ml

corresponding to up to 3 g lactulose

If diarrhoea occurs, the dosing regimen should be reduced.

In elderly patients and patients with renal or hepatic insufficiency no special dosage recommendations exist.

Duration of treatment

The duration of treatment has to be adopted according to the symptoms.

4.3 Contraindications

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

• Use in patients with galactosaemia.

• Gastrointestinal obstruction or subocclusive syndromes, digestive perforation or risk of digestive perforation, painful abdominal syndromes of undetermined cause.

4.4 Special warnings and precautions for use

In case of insufficient therapeutic effect after several days consultation of a physician is advised.

From the route of synthesis Lactulose oral solution may contain small amounts of sugars (not more than 66.7 mg/ml lactose, 100.05 mg/ml galactose and 6.67 mg/ml fructose). Lactulose should be administered with care to patients who are intolerant to lactose. The dose normally used in constipation should not pose a problem for diabetics.

15 ml of Lactulose contain 42.7 KJ (10.2 kcals) = 0.21 bu.

Use of laxatives in children should be exceptional and under medical supervision. Lactulose should be administrated with caution in infants and small children with autosomal recessive hereditary fructose intolerance. The defecation reflex may be altered during the treatment with lactulose.

Patients with rare hereditary problems of galactose or fructose intolerance, lactase deficiency or glucose-galactose mal-absorption should not take this medicine.

For patients with gastro-cardiac syndrome (Roemheld syndrome) lactulose should only be taken after consultation of a physician. If symptoms like meteorism or bloating occur in such patients after lactulose intake, the dose should be reduced or the treatment should be discontinued.

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

For elderly patients or patients that are in bad general condition and who take lactulose for a more than 6 months period, periodic control of electrolytes is indicated.

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

4.5 Interaction with other medicinal products and other forms of interaction

Lactulose may increase the loss of potassium induced by other drugs (e.g. thiazides, corticosteroids and amphothericin B). Concomitant use of cardiac glycosides can increase the effect of the glycosides through potassium deficiency.

With increasing dosage a decrease of pH-value in the colon is found. Therefore drugs which are released in the colon pH-dependently (e.g. Mesalazine) can be inactivated.

4.6 Fertility, pregnancy and lactation


Limited data on pregnant patients indicate no malformative nor foeto/neonatal toxicity. Animal studies do not indicate direct or indirect harmful effects with respect to pregnancy, embryonal/foetal development, parturition or postnatal development (see section 5.3).

The use of lactulose may be considered during pregnancy if necessary.


Lactulose can be used during breastfeeding.

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

Flatulence may occur during the first few days of treatment. As a rule it disappears after a couple of days. When dosages higher than instructed are used, abdominal pain and diarrhoea may occur. In such a case the dosage should be decreased.

Gastrointestinal disorders

Very common (≥ 1/10):

Flatulence, abdominal pain,

Common (≥ 1/100 < 1/10):

nausea and vomiting; if dosed too high, diarrhoea.


Electrolyte imbalance due to diarrhoea

4.9 Overdose

If the dose is too high, the following may occur:


Diarrhoea and abdominal pain.


Cessation of treatment or dose reduction. Extensive fluid loss by diarrhoea or vomiting may require correction of electrolyte disturbances.

5. Pharmacological properties
5.1 Pharmacodynamic properties

Pharmacotherapeutic group: Osmotically acting laxatives.

ATC code: A06A D11

Lactulose is a synthetic disaccharide formed from D-galactose and fructose. In the colon lactulose is metabolised by bacterial enzymes to short chained fatty acids mainly lactic and acetic acid as well as methane and hydrogen. This effect leads to a decrease of the pH-value and an increase of the osmotic pressure in the colon. This causes stimulation of peristalsis and an increase of the water content of the faeces.

In higher dosage lactulose causes a reduction of the pH-value, which results in an increased H+-concentration and a shift from NH3 (absorbable) to NH4+ (non-absorbable). The nitrogen excretion in the stool is accelerated. This effect may be used in the treatment of hyperammonaemia. In the treatment of hepatic encephalopathy lactulose reduces the concentration of NH3 in the blood by about 25-50 %.

Lower pH in the colon leads to suppression of proteolytic bacteria, which are involved in the formation of ammonia. Decrease in pH is caused by increasing the content of acidophilic bacteria (e.g. Lactobacillus). Reduced pH and the osmotic effect cleanse the colon; this stimulates the bacteria to use ammonia for bacterial protein synthesis.

5.2 Pharmacokinetic properties

Lactulose is practically not absorbed, because in man there is no corresponding disaccharidase available in the upper intestinal tract. Not being absorbed as such, it reaches the colon unchanged. There it is metabolised by the colonic bacterial flora. Metabolism is complete at doses up to 25-50 g or 40-75 ml; at higher dosages, a proportion may be excreted unchanged.

5.3 Preclinical safety data

Preclinical data based on studies of single and repeated dose toxicity reveal no special hazards for humans. A long-term animal study does not give reference to tumorigenic potential. Lactulose was not teratogenic in mice, rats and rabbits. After oral administration systemic toxicity is not to be expected due to the pharmacological and pharmacokinetic properties of lactulose.

6. Pharmaceutical particulars
6.1 List of excipients


6.2 Incompatibilities

Not applicable.

6.3 Shelf life

3 years

After first opening: 1 year

6.4 Special precautions for storage

Do not store above 25°C

6.5 Nature and contents of container

Brown PET bottles with polyethylene screw cap or polypropylene closure containing 100ml, 10 x 100 ml, 200ml, 250 ml, 300ml, 500 ml, 1000 ml

White PET bottles with polyethylene screw cap or polypropylene closure containing 100 ml, 200 ml, 300 ml, 500 ml, 1000 ml

Brown glass bottles with polyethylene screw cap containing 100ml, 200ml, 250 ml, 300ml, 500 ml, 1000 ml

As measuring device a measuring cup (polyproylene) with filling marks at 5, 10, 15, 20, 25 and 30 ml is added

Not all pack sizes may be marketed.

6.6 Special precautions for disposal and other handling

No special requirements.

7. Marketing authorisation holder

Sandoz Limited

Frimley Business Park




GU16 7SR

United Kingdom

8. Marketing authorisation number(s)

PL 04416/1310

9. Date of first authorisation/renewal of the authorisation

Date of first authorisation: 26/11/2012

Date of latest renewal: 23/06/2015

10. Date of revision of the text