Consumer medicine information

Duphalac Oral liquid



Brand name

Duphalac Oral liquid

Active ingredient





Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Duphalac Oral liquid.

What is in this leaflet

This leaflet answers some common questions about DUPHALAC.

It does not contain all the available information.

It does not take the place of talking to your doctor or pharmacist.

If you have any concerns about taking this medicine, ask your doctor or pharmacist.

Keep this leaflet with the medicine.

You may need to read it again.

What DUPHALAC is used for

DUPHALAC belongs to a group of medicines known as laxatives.

DUPHALAC is used to treat chronic constipation. It can be taken by pregnant women.

It works by increasing the amount of water and stool bulk in the bowel, promoting normal bowel activity.

DUPHALAC can also be used to treat portal-systemic encephalopathy (PSE), also known as hepatic encephalopathy (a disease of the brain that occurs when the liver is not working properly. Symptoms are caused by too much ammonia in the blood). It works by lowering the level of ammonia in the blood.

DUPHALAC can be used where a soft stool is considered of medical benefit (haemorrhoids, anal surgery).

Ask your doctor or pharmacist if you have any questions about why DUPHALAC has been prescribed or recommended for you.

Your doctor or pharmacist may have prescribed or recommended DUPHALAC for another reason.

There is no evidence that DUPHALAC is addictive.

Before you take DUPHALAC

When you must not take it

Do not take DUPHALAC if you:

  • Are allergic to lactulose, galactose, lactose or any other sugar
  • Have galactosaemia
  • Have a disaccharidase deficiency
  • Are on a low-galactose or galactose-free diet
  • Are on a lactose-free diet
  • Have a bowel obstruction (blockage other than normal constipation).

Do not take DUPHALAC after the expiry date printed on the label or if the cap seal is broken.

If it has expired or is damaged, return it to your pharmacist for disposal.

If you are not sure whether you should start taking DUPHALAC, talk to your doctor or pharmacist.

Before you start to take it

Tell your doctor or pharmacist if you have allergies to:

  • any other medicines.
  • any other substances, such as foods, preservatives or dyes.

Tell your doctor or pharmacist if you have or have had any medical conditions, especially the following:

  • diabetes
  • lactose intolerance.

Tell your doctor or pharmacist if you are breast-feeding or plan to breast-feed.

Your doctor or pharmacist will discuss the possible risks and benefits of using DUPHALAC during breast-feeding.

DUPHALAC has no or minor influence on the ability to drive and use machines.

If you have not told your doctor or pharmacist about any of the above, tell them before you start taking DUPHALAC.

Taking other medicines

Tell your doctor or pharmacist if you are taking any other medicines, including any that you buy without a prescription from your pharmacy, supermarket or health food shop.

How to take DUPHALAC

Follow all directions given to you by your doctor or pharmacist carefully.

They may differ from the information contained in this leaflet.

If you do not understand the instructions, ask your doctor or pharmacist for help.

How much to take

Chronic Constipation
The usual starting dose for constipation in adults is 15 to 45 mL daily, and the maintenance dose is 15 to 30 mL daily.

It may take 1-2 days for DUPHALAC to work fully.

DUPHALAC should be given to children and infants under medical supervision. The usual doses are:

Infants under 1 year:
Initial dose (first 3 days): 5 mL daily
Maintenance dose: 5 mL daily

Children 1-6 years:
Initial dose (first 3 days): 5 to 10 mL daily
Maintenance dose: 5 to 10 mL daily

Children 7-14 years:
Initial dose (first 3 days): 15 mL daily
Maintenance dose: 10 to 15 mL daily

As a general rule, patients with constipation should drink plenty of water and increase the amount of fibre in their diet.

Portal-Systemic Encephalopathy
The usual dose is 30 to 45 mL three to four times daily.

How to take it

DUPHALAC is a clear liquid to be swallowed. Swallow the medicine quickly. Do not keep it in your mouth.

Using a medicine measure will ensure you get the correct dose.

Duphalac may be taken diluted or undiluted.

When to take it

DUPHALAC is best taken at the same time each day, preferably at breakfast time.

Follow the instructions given to you by your doctor or pharmacist.

How long to take it

Prolonged use of laxatives is undesirable. If symptoms persist, seek medical advice.

Continue taking DUPHALAC for as long as your doctor or pharmacist tells you.

If you forget to take it

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

Otherwise, take it as soon as you remember, and then go back to taking DUPHALAC as you would normally.

Do not take a double dose to make up for the dose that you missed.

This may increase the chance of you getting an unwanted side effect.

If you are not sure what to do, ask your doctor or pharmacist.

If you have trouble remembering to take your medicine, ask your pharmacist for some hints.

If you take too much (overdose)

Immediately telephone your doctor or pharmacist or the Poisons Information Centre (telephone 13 11 26), or go to Accident and Emergency at your nearest hospital, if you think that you or anyone else may have taken too much DUPHALAC. Do this even if there are no signs of discomfort or poisoning.

Symptoms of an overdose are likely to be diarrhoea and abdominal cramps.

While you are taking DUPHALAC

Things you must do

Tell any other doctors, dentists, pharmacists or other healthcare professionals such as naturopaths, who are treating you that you are taking DUPHALAC.

If you are about to be started on any new medicine, tell your doctor, dentist, pharmacist or other healthcare professional that you are taking DUPHALAC.

If you need to have a colonoscopy or proctoscopy, tell your doctor that you are taking DUPHALAC.

Things you must not do

Do not take DUPHALAC to treat any other complaints unless your doctor or pharmacist tells you to.

Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking DUPHALAC.

DUPHALAC helps most people with chronic constipation, but it may have unwanted side effects in a few people. All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side effects.

Ask your doctor or pharmacist to answer any questions you may have.

During the first few days of taking DUPHALAC, you may feel bloated as a result of increased wind and intestinal cramps. These effects are usually mild and disappear after a few days.

At high doses you may suffer diarrhoea. If this happens, reduce the dose and/or tell your doctor or pharmacist.

Tell your doctor or pharmacist if you notice any of the following and they worry you:

  • nausea
  • vomiting.

These side effects are uncommon.

Very rarely, infants given DUPHALAC may develop dehydration.

Other side effects not listed above may occur in some patients. Tell your doctor or pharmacist if you notice anything that is making you feel unwell.

Some of these side effects (for example, potassium levels in the blood) can only be found when your doctor orders blood tests.

After using DUPHALAC


Keep DUPHALAC in a cool place where the temperature stays below 25°C. Do not store DUPHALAC in the refrigerator or freezer.

Do not store DUPHALAC or any other medicine in the bathroom or near a sink.

Keep it where children cannot reach it.

A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.


If your doctor or pharmacist tells you to stop taking DUPHALAC or the liquid has passed the expiry date, ask your pharmacist what to do with any that is left over.

Product description

What it looks like

DUPHALAC is a clear to brownish yellow liquid.

DUPHALAC is available in 200 mL and 500 mL bottles.


Each 15 mL of Duphalac contains 10 g lactulose as the active ingredient, furthermore 1.5 g or less of galactose, 0.9 g or less of lactose, 0.7 g or less of epilactose, 0.3 g or less of tagatose, and 0.1 g or less of fructose.


BGP Products Pty Ltd
299 Lane Cove Road
Macquarie Park NSW 2113

Telephone: 1800 314 527

® Registered Trademark.

AUST R 13295

This leaflet was prepared 08th July 2015.


Brand name

Duphalac Oral liquid

Active ingredient





Name of the medicine



Galactose ≤ 1.5 g, lactose ≤ 0.9 g, epilactose ≤ 0.7 g, tagatose ≤ 0.3 g, fructose ≤ 0.1 g per 15 mL. Duphalac oral solution may also contain sulfites and very small amounts of hydrogen peroxide and sodium hydroxide from the route of synthesis.


Lactulose is 4-O-β-D-galactopyranosyl-D-fructose, a synthetic disaccharide of galactose combined with the furanose form of fructose, and produced by alkaline epimerisation of lactose. Lactulose is soluble in water, 76.4% w/w at 30°C.
Duphalac is a sweet, clear, colourless to slightly yellow liquid with a specific gravity of 1.33. Each 15 mL of Duphalac contains 10 g lactulose as the active ingredient, furthermore 1.5 g or less of galactose, 0.9 g or less of lactose, 0.7 g or less of epilactose, 0.3 g or less of tagatose, and 0.1 g or less of fructose.
Duphalac oral solution may also contain sulfites and very small amounts of hydrogen peroxide and sodium hydroxide from the route of synthesis.


Therapeutic category.

Experimental data on lactulose given orally to man indicate that lactulose is poorly absorbed from the gastrointestinal tract and no enzymes capable of hydrolysis of lactulose into its component monosaccharides are known to be present in human gastrointestinal tissue. Lactulose reaches the colon virtually unchanged. There it is metabolised by colonic bacteria to low molecular weight acids, i.e. lactic acid and other short chain carboxylic acids. Metabolism is complete at doses up to 25-50 g or 40-75 mL; at higher dosages, a proportion may be excreted unchanged.
Lactulose given orally to man results in only small amounts reaching the blood by absorption through the small intestine probably by a nonmediated diffusion mechanism. Otherwise small increases in blood sugar levels are probably attributable to the small amounts of galactose and lactose also present in Duphalac. Urinary excretion has been determined to be 3% or less and is essentially complete within 24 hours. A small quantity of lactulose is probably hydrolysed in the colon into its constituent monosaccharides, galactose and fructose. The end result is a change in osmotic pressure and acidification of the colonic contents resulting in an increase in stool water content with resultant distention and softening of the stools, which in turn promotes increased peristalsis and bowel evacuation. In patients with chronic constipation, lactulose increases the number of bowel movements per day and the number of days when bowel movements occur.
Lactulose strengthens the growth of the health promoting bacteria of the genus Bifidobacterium and may suppress potentially pathogenic bacteria like Clostridium and Escherichia coli. Consequently, it is often described as a prebiotic substance. Its effects on the balance of the intestinal flora may contribute to its action in hepatic encephalopathy (see Hepatic encephalopathy, below).

Metabolism in infants.

Administration of lactulose to infants fed with cow's milk produces a predominance of lactobacilli in the stools, thus simulating the intestinal flora following maternal milk feeding. Lactulose also appears to increase the production of lysosome in infants receiving cow's milk.

Hepatic encephalopathy.

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome from a disorder of cerebral function, which can complicate all forms of liver disease. The major sites of cerebral involvement are the cortex extrapyramidal system and cerebellum. Clinical features include intellectual deterioration, disturbances of consciousness and neurological abnormalities.
It is generally accepted that HE involves exposure of the brain to nitrogenous substances arising from the gut from bacterial metabolism of protein, with ammonia being implicated most commonly, together with an alteration of the pattern of amino acids entering the central nervous system.
The basic action of lactulose in HE is aimed at reducing nitrogenous intoxication by decreasing blood ammonia concentration. Lactulose is degraded in the large bowel bacterial flora, mainly to acetic and lactic acids, thus reducing the intraluminal pH to below pH 5.0. This acidification of colonic contents results in the retention of ammonia as the ammonium ion [NH4]+. In effect, ammonia, amines and various amides, and other basic nitrogenous substances are thus trapped, reducing their absorption into the blood. Since the colonic contents are more acid than the blood, ammonia can be expected to migrate from the blood into the colon to form the ammonium ion. Lowering of faecal pH is also thought to suppress urease producing organisms, and to foster the growth of saccharolytic bacteria (Lactobacillus acidophilus) rather than E. coli, a more efficient ammonia producing bacterium. The diarrhoeal action of lactulose is synergistic in repelling the trapped ammonium ion from the colon.
Thus, of several proposals, the therapeutic action of lactulose in ameliorating the symptoms of HE is considered to be the result of the following.
Reduction of faecal pH leading to reduced ammonia absorption via nonionic diffusion and/or diffusion of ammonia from the blood into the gut. The trapped ammonia is then excreted in the stools.
Suppression of urease producing organisms.
Induction of an osmotic type of diarrhoea which diminishes faecal stasis with reduction of nitrogenous substances for ammonia production. Decreased absorption of ammonia from the gut also results from shortening intestinal transit time.
The actual mechanism may be a combination of these effects.


i) For the treatment of acute hepatic encephalopathy and the prevention and treatment of chronic hepatic encephalopathy, including the stages of hepatic precoma and coma.
ii) For the treatment of chronic and habitual constipation.
iii) Where a soft stool is considered of medical benefit (haemorrhoids, postcolonic/ anal surgery).


Contraindicated in patients with hypersensitivity to the active substance or to any of the excipients; galactosaemia; gastrointestinal obstruction, digestive perforation, or risk of digestive perforation.


Painful abdominal symptoms of undetermined cause should be evaluated to exclude undiagnosed perforation or obstruction or undiagnosed disease/condition that predisposes to either before the treatment is started.
In case of insufficient therapeutic effect after several days the dose and/or additional measures should be reconsidered.
A theoretical hazard may exist for patients treated with lactulose who may be required to undergo electrocautery procedures during proctoscopy or colonoscopy. If sugars reach the colon then bacterial breakdown causes hydrogen production. Accumulation of hydrogen gas in significant concentration in the presence of an electrical spark may result in an explosive reaction. Although this complication has not been reported with lactulose, patients on lactulose therapy undergoing such procedures should have a thorough bowel cleansing with nonfermentable solution.
Duphalac contains galactose (1.5 g or less per 15 mL) and lactose (0.9 g or less per 15 mL) and should be used with caution in diabetics as blood glucose levels may be elevated, usually after extended use.
Patients with rare hereditary problems of galactose or fructose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Lactulose should be administered with care to patients who are intolerant to lactose.
Chronic misuse of laxatives may result in electrolyte imbalance, in particular serum potassium levels may be decreased. Elderly debilitated patients who receive Duphalac for more than six months should have serum electrolytes measured periodically.
When administered as a retention enema, due to strong cathartic effect, faecal incontinence, bedsoiling, and peri-anal irritation due to the acidic stool can be expected. The hydration status of the patient should be observed carefully.
The defaecation reflex may be altered during the treatment with lactulose (see Pharmacology). This alteration is considered to improve bowel habits during constipation and can be seen as a normalization of stool frequency.
In the overall management of hepatic encephalopathy, it should be recognised that there is a pre-existing liver disease and efforts should be made to identify and treat the precipitating cause of hepatic coma. Thus the overall management of hepatic encephalopathy should include dietary protein restriction, bowel cleansing and sterilisation, correction of electrolyte and fluid imbalance, provision of caloric and nutritional needs and treatment of underlying liver disease.

Use in pregnancy.

Lactulose has been shown to be effective for the treatment of constipation associated with pregnancy when administered to women at different stages of pregnancy.
Reproduction studies with daily oral doses of lactulose (50% w/w) up to 12 mL per kg in mice and rats and 6 mL per kg in rabbits have not revealed any evidence of an increased occurrence of foetal damage or other deleterious effects.

Use in lactation.

There are no data on the secretion of lactulose in breast milk or the effect on the breastfed infant. Risk-benefit should be considered.

Paediatric use.

It is recommended that if Duphalac is given to infants and children this should be done under medical supervision.

Effects on ability to drive and use machines.

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


There have been conflicting reports about the concomitant use of neomycin and lactulose although in some situations the two drugs administered together are more effective than either one alone.
Theoretically, the elimination of certain colonic bacteria by neomycin and possibly other anti-infective agents may interfere with the desired degradation of lactulose and thus prevent the acidification of colonic contents. There have been some reports that lactulose fermenting bacteria are relatively resistant to neomycin, which might explain why a combination could work in some cases. Thus the status of the lactulose treated patient should be closely monitored (including stool pH) in the event of concomitant oral antibiotic therapy.

Adverse Effects

Initial dosing may produce gaseous distension with flatulence and intestinal cramps in about 20% of patients. These effects are usually mild and transient.
Excessive dosage can lead to diarrhoea. If untreated, potential complications of diarrhoea may include fluid loss and electrolyte disturbances such as hypokalaemia and hypernatraemia.
Less frequently, nausea, vomiting, anorexia and increased thirst have been reported.
The following undesirable effects have been experienced with the below indicated frequencies in lactulose treated patients in placebo controlled clinical trials (very common (≥ 1/10); common (≥ 1/100 to < 1/10); uncommon (≥ 1/1000 to < 1/100); rare (≥ 1/10,000 to < 1/1000); very rare (< 1/10,000); not known (cannot be estimated from the available data)).

Gastrointestinal disorders.

Very common: diarrhoea. Common: flatulence, abdominal pain, nausea, vomiting.

Metabolism and nutrition disorders.

Unknown: anorexia.


Uncommon: electrolyte imbalance due to diarrhoea.

General disorders and administration site conditions.

Unknown: increased thirst.

Paediatric population.

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

Dosage and Administration

The lactulose solution may be administered diluted or undiluted. The dose should be titrated according to the clinical response. A single dose of lactulose should be swallowed in one and should not be kept in the mouth for an extended period of time.

Hepatic encephalopathy.

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

Dosing in HE (for adults only).

The usual dosage is 30 to 45 mL three to four times daily. The dosage may be adjusted every day or two to produce two or three soft stools daily.
Hourly doses of 30 to 45 mL of Duphalac may be used to induce the rapid laxation indicated in the initial phase of the therapy of hepatic encephalopathy. When the laxative effect has been achieved, the dose of Duphalac may then be reduced to the usual daily dosage.
Improvement in the patient's condition may take 24-48 hours to occur. Continuous long-term therapy is indicated to lessen the severity and prevent the recurrence of hepatic encephalopathy. The dose of Duphalac for this purpose is the same as the usual daily dose.
In the treatment of acute episodes of hepatic encephalopathy a rapid response is desirable. In such cases it is important to avoid underdosage, and 50 mL every 1-2 hours can be given if necessary until two loose bowel actions have occurred. Thereafter doses may be reduced to usual doses (30 to 45 mL three to four times daily).
The administration of Duphalac as a retention enema is an alternative technique. This can be done by diluting Duphalac, and is of considerable value especially in the unconscious patient. In such cases 300 mL of Duphalac may be mixed with 700 mL of water or normal saline to be used as a retention enema; the enema is to be retained for 30-60 minutes, and repeated every 4-6 hours until the patient is able to take oral medication.

Chronic constipation.

Lactulose may be given as a single daily dose or in two divided doses, using the measuring cup.
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.
More serious constipation, and/or constipation such as caused by chemotherapy agents may require higher dosages. See Table 1.
When experiencing constipation patients should be advised to drink plenty of water, and increase the fibre content in their diet.


No toxicity in humans has been recorded to date. There have been no reports of accidental overdosage. In the event of acute overdosage it is expected that diarrhoea and abdominal cramps would be the main symptoms. Complications of diarrhoea may include fluid loss, or loss or disturbances of electrolytes, such as hypokalaemia and hypernatraemia, in which case treatment would consist of fluid and electrolyte replacement. Treatment would include cessation of lactulose or dose reduction. Extensive fluid loss by diarrhoea or vomiting may require correction of electrolyte disturbances.


Bottle containing 200 mL or 500 mL.

Poison Schedule