Lactulose

Please note: these are basic guidelines, refer to your doctor for a professional medical opinion.

Popular brand names:

Duphalac (dry powder/syrup), Lacson (syrup), Laxette (dry powder/solution)

Drug group:

Laxative

Prescription needed?

No

What does it do?

• Lactulose is mainly used for the relief of constipation and faecal impaction
• It is also used for preventing and treating hepatic encephalopathy (a brain disturbance associated with liver failure)

How does it work?

• Lactulose softens the stool by increasing the amount of water in the large intestine
• It acts locally in the bowel and is not absorbed into the body – it is safer and less likely than other laxatives to disrupt normal bowel function

How should it be used?

Drink plenty of fluids while using lactulose - up to 8 glasses of water daily

What is the typical dosage?

Your doctor will recommend a dosage tailored to your need, but typically:

• Chronic constipation: total 15–30ml daily, taken 2 x daily
• Liver failure: total 90–150ml daily, taken 3–4 x daily

How quickly will it start to work?

Within 24–48 hours                      

How long will the effects last?

6–18 hours             

When should I stop using it?

When used for constipation, it can be stopped when no longer needed.

Is it safe for prolonged use?

Continued use may increase the risk of dental caries in children.          

What are the possible side effects?

Side effects are rarely serious and often disappear as your body adjusts to the drug.

The following have been reported:

• More common: flatulence, belching, nausea, vomiting, abdominal cramps/distension
• Less common: diarrhoea (indicates that you need to reduce your dose or stop the drug)
• Report to your doctor before taking your next dose if you experience: persistent severe constipation despite use for a few days, severe abdominal pain

What other considerations are important?

Dosage may be adjusted by your doctor under certain conditions.

• Certain health problems: diabetes, lactose intolerance or galactosaemia
• Other medicines: Anticoagulants especially warfarin
• Pregnancy and breast-feeding: No evidence of risk
• Children: Reduced dose necessary
• Over 60: No special problems
• Driving and hazardous work: No known problems
• Alcohol: No known problems