Lactulose

General

  • Type: osmotic laxative
  • Dosage Forms: 10g/15L solution
  • Routes of Administration: oral, NG, rectal
  • Common Trade Names: Kristalose

Adult Dosing

Hepatic encephalopathy

  • 30-45mg PO TID or QID or (300mL in 700cc H2O retention enema x30min)
  • titrate for 2-3 soft stools per day

Constipation

  • 15-50mL PO Qday - BID
  • max 60mL/day

Pediatric Dosing

Portal systemic encephalopathy

  • infants
    • 2.5-10ml/day PO divided TID-QID
    • titrate for 2-3 soft stools per day
  • children
    • 40-90ml/day PO divided TID-QID
    • titrate for 2-3 soft stools per day

Constipation

  • 1ml/kg PO Qday - BID
  • max 60mL/day

Special Populations

  • Pregnancy Rating: B (no evidence of risk)
  • Lactation risk: safety unknown
  • Renal Dosing
    • Adult: not defined
    • Pediatric: not defined
  • Hepatic Dosing
    • Adult: not defined
    • Pediatric: not defined

Contraindications

  • Allergy to class/drug
  • galactosemia
  • caution in DM
  • caution if colorectal electrocautery procedures

Adverse Reactions

Serious

  • diarrhea, severe (excessive dose)
  • electrolyte disorders (excessive dose)
  • metabolic acidosis (excessive dose)

Common

  • flatulence
  • intestinal cramping
  • abdominal distention
  • nausea/vomiting

Pharmacology

  • Half-life: unknown
  • Metabolism: colon, <3% systemic absorption
  • Excretion: feces (100% unchanged), urine < 3%
  • Mechanism of Action: increases stool water content, increases stool acidity trapping NH4 ions

Comments

See Also

References