Lactulose: Uses, How It Works, Medicines
Lactulose is an osmotic laxative, a medicine that softens stools by drawing water into the bowel. It is used to treat constipation and, under specialist care, a liver condition called hepatic encephalopathy. It can take 2 to 3 days to work.
Also known as: Lactulose solution, Lactulose syrup, Lactulose oral solution, Lactulose 10 g/15 mL, Duphalac, Looz, Cremaffin, Osmotic laxative, Constipation syrup
Pharmacist review in progress. This page is based on the sources listed below and is being checked by our registered pharmacist.
How does Lactulose work?
Lactulose is not absorbed in the upper gut, so it passes into the bowel and draws water in with it. This softens the stool and makes it easier to pass.
How to take Lactulose
Follow the label or your doctor's advice. Lactulose is a liquid taken by mouth, usually once or twice a day, and the amount depends on the reason it was prescribed. Drink plenty of fluids while taking it.
Side effects of Lactulose
Lactulose usually causes only mild side effects, which often ease after a few days.
Uncommon or mild
- Wind (gas), which should ease after a few days
- Bloating
- Stomach ache
- Feeling sick (nausea) or being sick (vomiting)
- Diarrhoea
Rare but serious: get medical help
- Signs of a severe allergic reaction: swelling of the face, lips or throat or difficulty breathing. Get medical help immediately
- Long-lasting diarrhoea, which can cause dehydration and a low potassium level, with weakness, muscle cramps or an irregular heartbeat
- Severe stomach pain or vomiting that does not settle
Who should be careful
Lactulose is not right for everyone, and constipation that does not improve needs a doctor's check.
When the label says not to use it
- A blocked bowel (not caused by constipation)
- Galactosaemia
- Allergy to lactulose
- Lactose intolerance, galactosaemia, or allergy to galactose or fructose: the syrup contains small amounts of these sugars
- Bowel conditions such as irritable bowel syndrome, diverticular disease or Crohn's disease: ask your doctor first
- Diabetes, especially at high doses: lactulose can affect blood sugar
- Constipation that does not improve after about 3 days, or that comes with blood in the stool, weight loss or pain, needs a doctor's check
- Pregnancy and breastfeeding: it can generally be used, but ask your doctor or pharmacist first
- Children: do not give to a child without a doctor's advice
Medicines and things that interact with Lactulose
Few specific interactions are listed for lactulose, but tell your doctor or pharmacist about everything you take.
- Other laxatives: using several together can cause diarrhoea and loss of body salts
- Some medicines and supplements may not mix well with lactulose; check the leaflet or ask a pharmacist
If someone takes too much
Taking too much lactulose mainly causes diarrhoea, stomach cramps and loss of body fluid. Drink plenty of fluids. If someone has taken much more than the label or doctor advised, or feels unwell, call 112 or go to the nearest hospital.
Regulatory status in India
Approved for sale in India. Whether a pack is sold on prescription or over the counter must be read from the pack. Single-ingredient lactulose was not found on the CDSCO banned list text checked for this batch.
Type of medicine
Lactulose belongs to this type of medicine.
Medicines that contain Lactulose
These medicines sold in India contain Lactulose. They are listed A to Z, not ranked.
- Duphalac · 10 g per 15 mL oral solution
What is Lactulose used for?
Medicines that contain Lactulose are used for these conditions.
Common questions
What is lactulose used for?
Lactulose is a laxative for constipation. A doctor may also prescribe it for a liver condition called hepatic encephalopathy. It should be used as the label or doctor advises, with plenty of fluids.
How long does lactulose take to work?
It can take 2 to 3 days to work, so a single dose may not bring quick relief. See a doctor if constipation is not better or gets worse after about 3 days.
Can lactulose be taken in pregnancy?
It can be taken in pregnancy and while breastfeeding, but ask your doctor or pharmacist first. Fibre, fluids and activity are the first steps for constipation in pregnancy.
Can I take lactulose every day?
Only if your doctor advises. Laxatives are meant for short-term use. If you need one often, see a doctor to find the cause. Do not stop a prescribed medicine for the liver without asking your doctor.
Sources
- Lactulose: a laxative for constipation. NHS (UK)
- Constipation. NHS (UK)
- ATC/DDD Index: A06AD11 lactulose. WHO Collaborating Centre for Drug Statistics Methodology
- List of drugs prohibited for manufacture and sale through gazette notifications under section 26A of the Drugs & Cosmetics Act 1940. Central Drugs Standard Control Organisation (CDSCO)