What does it do?

Lactulose is used to treat and prevent constipation. It is also sometimes used for other conditions.

How should you take it?

Take lactulose as directed with a glass of water. Measure the dose carefully. It can be mixed with fruit juice or water.

What if you forget a dose?

Should an occasional dose be missed it need not be taken later.

Can you take other medicines?

Some medicines available without a prescription may react with lactulose including:

  • other laxatives – discuss this with your pharmacist
  • anti-diarrhoea medicines such as loperamide (e.g. Imodium®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Farting, stomach cramps, bloating, diarrhoea, nausea, vomiting

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have heart, kidney, stomach or bowel problems, or need a galactose and/or lactose free diet.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Drink plenty of fluids while taking lactulose.
  • Do not use lactulose for longer than 1 week unless told to by your doctor.
  • If you have noticed a change in bowel habit that continues for longer than 2 weeks, talk to your doctor before taking lactulose.