II. Mechanism

  1. Converts Ammonia to unabsorbed Ammonium
  2. Produces Diarrhea
  3. Alters bowel flora

IV. Advantages

  1. Poorly absorbed (may be used in Renal Failure)

V. Disadvantages: Constipation

  1. Not as effective or well tolerated as Miralax

VI. Dosages

  1. Constipation
    1. Lactulose (Chronulac)
      1. Consider Sorbitol 70% as alternative agent
      2. Adults: 30 ml PO qhs
      3. Children (10 mg/15 ml) 1-3 cc/kg/day divided qd-bid
        1. Easier to administer to young children
      4. May cause abdominal cramping and Flatus
    2. Lactitol
      1. As effective as Lactulose with less pain and Flatus
      2. Pitzalis (1995) Pediatr Med Chir 17(3):223-6 [PubMed]
  2. Hepatic Encephalopathy
    1. Initial: 30-50 ml PO qh until Diarrhea
    2. Next: 15-30 ml PO tid-qid prn 2-3 stools/day
  3. Hepatic Coma
    1. Lactulose 300 ml in 700 ml water retention enema

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Related Studies

Cost: Medications

Lactulose syrup (on 6/18/2017 at Walmart.com)
Lactulose syrup #236 ml for $4.00 $0.02 each
Lactulose syrup #708 ml for $10.00 $0.01 each
lactulose (on 4/19/2017 at Medicaid.Gov Survey of pharmacy drug pricing)
LACTULOSE 10 GM/15 ML SOLUTION Generic $0.01 per ml

Ontology: Lactulose (C0022957)

Definition (NCI) A disaccharide (sugar) synthesized from fructose and galactose, Lactulose is used to treat constipation and some liver diseases. Nondigestible in mammals, lactulose passes unabsorbed down to the large intestine where resident bacteria consume it and produce lactic, acetic, and formic acids, which draw fluid into the bowel to soften the stool (laxative effect). Acidification of the colon contents attracts ammonia from the bloodstream, assisting stool excretion; helpful in liver failure when ammonia cannot be detoxified. (NCI04)
Definition (MSH) A synthetic disaccharide used in the treatment of constipation and hepatic encephalopathy. It has also been used in the diagnosis of gastrointestinal disorders. (From Martindale, The Extra Pharmacopoeia, 30th ed, p887)
Concepts Pharmacologic Substance (T121) , Carbohydrate (T118)
MSH D007792
SnomedCT 111137007, 273945008
LNC LP61647-1, LP173648-9
English Lactulose, D-Fructose, 4-O-beta-D-galactopyranosyl-, lactulose, lactulose (medication), laxatives lactulose, LACTULOSE, 4-O-beta-D-Galactopyranosyl-D-fructofuranose, Lactulose [Chemical/Ingredient], Lactulose product, Lactulose (product), Lactulose (substance)
Swedish Laktulos
Czech laktulosa
Finnish Laktuloosi
Polish Laktuloza
Japanese ラクツロース, ピアーレ, モニラック, ラグノス
Spanish lactulosa (producto), lactulosa (sustancia), lactulosa, Lactulosa
French Lactulose
German Lactulose
Italian Lattulosio
Portuguese Lactulose