Action And Clinical Pharmacology: Experimental data indicate that lactulose is not significantly absorbed in the small intestine and reaches the colon essentially unchanged. There it is metabolized by bacteria with the formation of low molecular weight acids that acidify the colonic contents. Less than 2% of lactulose is absorbed systemically.
Two mechanisms are believed to be involved in the laxative action of lactulose: 1) Metabolism of lactulose by bacteria results in reduced colonic pH, which stimulates peristalsis and decreases stool transit time. In turn, decreased water reabsorption from the feces further facilitates the passage of soft, well-formed stools. 2) Increased osmotic pressure of fecal material secondary to an increase in colonic organic acids results in accumulation of fluid from surrounding tissues, helping to soften stool mass.
This action takes place gradually, with increased stool volume and frequency normally observed within 24 to 48 hours.
Indications And Clinical Uses: Relief of constipation, including chronic constipation.
Contra-Indications: Since lactulose crystals contain galactose and lactose, use is contraindicated in patients who require a low galactose diet.
Lactulose is contraindicated in cases of bowel obstruction.
Precautions: General: As with all laxatives, overuse or extended use may cause dependence for bowel function. No laxative should be taken for more than 1 week without the advice of a physician. No laxative should be used in the presence of abdominal pain, nausea, fever, or vomiting, as such symptoms may signal appendicitis or an inflamed bowel.
Lactulose crystals contain galactose and lactose and should be used with caution in diabetics.
Pregnancy: Animal studies have not revealed significant adverse effects. However, lactulose should not be taken by women who are pregnant, or planning to become pregnant, except on the advice of a physician.
Drug Interactions: No laxative should be taken within 2 hours of another medication, because the desired effect of the other medication may be reduced.
Adverse Reactions: Initial dosing may produce flatulence and intestinal cramps, which are usually transient. Excessive dosage can lead to diarrhea. Nausea has been reported.
Symptoms And Treatment Of Overdose: Symptoms and Treatment: Diarrhea and abdominal cramps may be controlled by a dosage reduction.
Dosage And Administration: Usual dosage: 10 to 20 g (15 to 30 mL)/day (i.e., 1 to 2 packets/day). After a few days, the dose may be increased up to 40 g (60 mL)/day (i.e., 4 packets/day) if necessary.
A maximum dose of 40 g/day (60 mL, or 4 packets/day) should not be exceeded.
One packet (10 g) of lactulose is equivalent to 15 mL of lactulose crystals. Energy: approximately 2 kcal/packet.
Duphalac should be taken in a single dose at the same time daily, such as breakfast. Crystals can be taken dry from a spoon and washed down with a glass of water or another liquid. The crystals may also be sprinkled on food or mixed with water or fluids before swallowing.
Availability And Storage: Each packet contains: lactulose crystals 10 g (15 mL). Lactulose is a synthetic disaccharide analogue of lactose. Also contains galactose, lactose and other sugars. Energy: 8.4 kJ (2 kcal). Boxes of 10. Store at room temperature (between 10 and 25°C). Keep out of the reach of children.
DUPHALAC® Solvay Pharma Lactulose Crystals Laxative