Yes

Ammonium Detoxicant; Laxative, Miscellaneous

Adjunct in the prevention and treatment of portal-systemic encephalopathy (PSE); treatment of chronic constipation

B

Patients with galactosemia and require a low galactose diet, hypersensitivity to any component

Use with caution in patients with diabetes mellitus; monitor periodically for electrolyte imbalance when lactulose is used >6 months or in patients predisposed to electrolyte abnormalities (eg, elderly); patients receiving lactulose and an oral anti-infective agent should be monitored for possible inadequate response to lactulose

>10%: Gastrointestinal: Flatulence, diarrhea (excessive dose)

1% to 10%: Gastrointestinal: Abdominal discomfort, nausea, vomiting

Symptoms of overdose include diarrhea, abdominal pain, hypochloremic alkalosis, dehydration, hypotension, hypokalemia

Treatment includes supportive care

Decreased effect: Oral neomycin, laxatives, antacids

Keep solution at room temperature to reduce viscosity; discard solution if cloudy or very dark

The bacterial degradation of lactulose resulting in an acidic pH inhibits the diffusion of NH₃ into the blood by causing the conversion of NH₃ to NH₄+; also enhances the diffusion of NH₃ from the blood into the gut where conversion to NH₄+ occurs; produces an osmotic effect in the colon with resultant distention promoting peristalsis

Absorption: Oral: Not absorbed appreciably following administration; this is desirable since the intended site of action is within the colon

Metabolism: By colonic flora to lactic acid and acetic acid, requires colonic flora for primary drug activation

Elimination: Primarily in feces and urine (~3%)

Diarrhea may indicate overdosage and responds to dose reduction

Infants: 2.5-10 mL/day divided 3-4 times/day; adjust dosage to produce 2-3 stools/day

Older Children: Daily dose of 40-90 mL divided 3-4 times/day; if initial dose causes diarrhea, then reduce it immediately; adjust dosage to produce 2-3 stools/day

Constipation:

Children: 5 g/day (7.5 mL) after breakfast

Adults:

Acute PSE:

Oral: 20-30 g (30-45 mL) every 1-2 hours to induce rapid laxation; adjust dosage daily to produce 2-3 soft stools; doses of 30-45 mL may be given hourly to cause rapid laxation, then reduce to recommended dose; usual daily dose: 60-100 g (90-150 mL) daily

Rectal administration: 200 g (300 mL) diluted with 700 mL of H₂0 or NS; administer rectally via rectal balloon catheter and retain 30-60 minutes every 4-6 hours

Constipation: Oral: 15-30 mL/day increased to 60 mL/day if necessary

Contraindicated in patients on galactose-restricted diet; may be mixed with fruit juice, milk, water, or citrus-flavored carbonated beverages

Blood pressure, standing/supine; serum potassium, bowel movement patterns, fluid status, serum ammonia

None reported

None reported

No information available to require special precautions

No effects or complications reported

Not for long-term use. Take as directed, alone, or diluted with water, juice or milk, or take with food. Laxative results may not occur for 24-48 hours; do not take more often than recommended or for a longer time than recommended. Do not use any other laxatives while taking lactulose. Increased fiber, fluids, and exercise may help reduce constipation. Do not use if experiencing abdominal pain, nausea, or vomiting. Diarrhea may indicate overdose. May cause flatulence, belching, or abdominal cramping. Report persistent or severe diarrhea or abdominal cramping. Breast-feeding precautions: Consult prescriber if breast-feeding.

Dilute lactulose in water, usually 60-120 mL, prior to administering through a gastric or feeding tube

Syrup: 10 g/15 mL (15 mL, 30 mL, 237 mL, 473 mL, 946 mL, 1890 mL)

Lederle FA, Busch DL, Mattox KM, et al, "Cost-Effective Treatment of Constipation in the Elderly: A Randomized Double-Blind Comparison of Sorbitol and Lactulose," Am J Med, 1990, 89(5):597-601.