Lactulose

ATC code
A06AD11
Therapeutic class
Osmotic laxative · Non-absorbable synthetic disaccharide
Forms
oral solution, rectal solution, oral powder for solution
Brand names
Enulose (US) · Generlac (US) · Constulose (US) · Duphalac (ES) · Melaxose (FR)
Overall confidence
high

Regulatory sources consulted

Approved indications

Contraindications

Absolute

  • Patients who require a low galactose diet (lactulose contains galactose).
  • Gastrointestinal obstruction or subocclusive syndromes.

Relative

  • Phenylketonuria (for formulations containing aspartame).

Clinical warnings

Drug interactions

Adverse events

Common (≥1%)

abdominal distension · flatulence · belching · abdominal cramps · diarrhea (dose-dependent)

Rare but serious

severe diarrhea with dehydration · hypernatremia · hypokalemia

Pregnancy and lactation

FDA category: B

Animal studies have not revealed evidence of fetal harm. However, there are no adequate and well-controlled studies in pregnant women. Since systemic absorption is minimal, risk to the fetus is considered low. Use during pregnancy only if clearly needed. Compatible with breastfeeding.

Recent literature (PubMed)