From the Guidelines
The dose range of lactulose for treating constipation is 10-40 g daily.
Key Points
- The initial dose of lactulose is typically 10-20 g (15-30 mL or 1-2 packets) daily 1.
- The dose may be increased to 40 g (60 mL or 2-4 packets) daily if needed 1.
- Lactulose is an osmotic laxative that exerts its effect in the colon to promote peristalsis 1.
- Common side effects of lactulose include bloating and flatulence, which are dose-dependent and may limit its use in clinical practice 1.
- The use of lactulose can be considered if symptoms of constipation have failed to improve with fiber and over-the-counter (OTC) laxatives, and individuals do not experience significant bloating or abdominal pain with lactulose use 1.
From the FDA Drug Label
The usual adult, oral dosage is 2 to 3 tablespoonfuls (30 mL to 45 mL, containing 20 grams to 30 grams of lactulose) three or four times daily. Pediatric: ...the total daily dose is 40 mL to 90 mL. On the basis of information available, the recommended initial daily oral dose in infants is 2. 5 mL to 10 mL in divided doses.
The dose range of lactulose for treating constipation is:
- Adults: 20 grams to 30 grams (30 mL to 45 mL) three or four times daily
- Pediatric:
- Infants: 2.5 mL to 10 mL in divided doses
- Older children and adolescents: 40 mL to 90 mL daily 2
From the Research
Dose Range of Lactulose for Treating Constipation
The dose range of lactulose for treating constipation varies according to different studies.
- A study published in 1996 3 used a daily dose of 20 g of lactulose in one or two intakes to treat idiopathic chronic constipation.
- Another study published in 2006 4 found that a dose of 10-20 g per day of lactulose produced a tonic contraction in the human colon and was effective in treating constipation.
- A study published in 1981 5 compared the laxative effects of lactulose syrup at two dose levels, 30 and 60 ml/day, and found that the laxative effects were dose-related.
- A study published in 1993 6 used a daily dose of 20.1 g of lactulose to treat chronic constipation in geriatric patients.
- A systematic review published in 2010 7 compared the efficacy and safety of lactitol versus lactulose in the management of constipation and found that lactitol was comparable to lactulose in terms of efficacy, but had better acceptance and compliance by patients.