Absorption: Less than 3% absorbed after oral administration.
Distribution: Unknown.
Metabolism and Excretion: Absorbed lactulose is excreted unchanged in the urine. Unabsorbed lactulose is metabolized by colonic bacteria to lactic, acetic, and formic acids.
When used in hepatic encephalopathy, adjust dose until patient averages 2–3 soft bowel movements per day. During initial therapy, 30–45 mL may be given hourly to induce rapid laxation.
Darkening of solution does not alter potency.
PO Mix with fruit juice, water, milk, or carbonated citrus beverage to improve flavor. Administer with a full glass (240 mL) of water or juice. May be administered on an empty stomach for more rapid results.
Dissolve single dose packets (Kristalose) in 4 oz of water. Solution should be colorless to slightly pale yellow.
Rect: To administer enema, use rectal balloon catheter. Mix 300 mL of lactulose with 700 mL of water or 0.9% NaCl. Enema should be retained for 30–60 min. If inadvertently evacuated, may repeat administration.
Explain purpose of lactulose to patient. Instruct patient to take lactulose as directed.
Encourage patients to use other forms of bowel regulation, such as increasing bulk in the diet, increasing fluid intake, and increasing mobility. Normal bowel habits are individualized and may vary from 3 times/day to 3 times/wk.
Caution patients that this medication may cause belching, flatulence, or abdominal cramping. Health care professional should be notified if this becomes bothersome or if diarrhea occurs.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
Passage of a soft, formed bowel movement, usually within 24–48 hr.
Clearing of confusion, apathy, and irritation, and improved mental status in portal-systemic encephalopathy. Improvement may occur within 2 hr after enema and 24–48 hr after oral administration.