Each 100 mL of Duphalac syrup contains lactulose 67 g. It also contains galactose <11 g and lactose <6 g as excipients.
Pharmacology: In the colon, lactulose is broken down by colonic bacteria into low molecular organic acids. These acids lead to a lowering of pH in the colonic lumen and via an osmotic effect to an increase of the volume of the colonic contents.
These effects stimulate the peristalsis of the colon and normalize the consistency of the stools. The constipation is cleared and the physiological rhythm of the colon is reinstated.
In portal systemic encephalopathy (PSE) c.q. (pre) coma hepaticum, the effect has been attributed to suppression of proteolytic bacteria by an increase of acidophilic bacteria (eg, lactobacillus), trapping of ammonia in the ionic form by the acidification of the colonic contents, catharsis due to the low pH in the colon as well as an osmotic effect and alteration of the bacterial nitrogen metabolism by stimulating the bacteria to utilize ammonia for bacterial protein synthesis. Within this context, however, it should be realized that hyperammonia alone cannot explain the neuropsychiatric manifestations of PSE.
The ammonia however might serve as a model compound for other nitrogenous substances.
Pharmacokinetics: Lactulose is scantily absorbed after oral administration. Not being absorbed as such, it reaches the colon unchanged. There, it is metabolized by the colonic bacterial flora. Metabolism is complete at doses up to 25-50 g (40-75 mL): At higher dosages, a part may be excreted unchanged.
Chronic Constipation: Regulation of the physiological rhythm of the colon.
Portal Systemic Encephalopathy (PSE): Treatment and prevention of hepatic coma or pre-coma.
Where a soft stool is considered of medical benefit (haemorrhoids, post-colon/anal surgery).
The daily dosage should be adapted on individual basis.
The following serves as a guideline: Chronic Constipation: Starting Dose (For 3 Days): Adults and Children ≥15 years: 15-45 mL. Children 7-14 years: 15 mL, 1-6 years: 5-10 mL. Infants: 5 mL.
Maintenance Dose: Adults and Children ≥15 years: 15-30 mL. Children 7-14 years: 10-15 mL, 1-6 years: 5-10 mL. Infants: 5 mL.
As a rule, the dosage can be decreased after a couple of days to serve patients' needs. The dosage should preferably be taken in one time during breakfast. Onset of the clinical effect may take a couple of days. This is inherent to the mode of action of lactulose. Higher dosages can be considered if a positive response has not occurred after the first 2 days.
Pre-Coma and Coma Hepaticum: Starting Dose: 30-45 mL 3 times daily.
Maintenance Dose: Should be adapted as such the soft stools are produced maximally 2-3 times/day. The pH of the stools should be preferably 5-5.5.
Medical Benefit of the Stools: These are the same as in constipation. This indication can be included in constipation.
No data on cases of overdosing are available. If dosed too high, both headache and diarrhea can occur. In such instance, cessation of treatment will normally suffice.
Galactosaemia, bowel obstruction, hypersensitivity to any of the components of Duphalac.
Should the constipation not react to treatment after a couple of days or reoccur after treatment, then a physician should be consulted. If used by patients suffering from galactosaemia or lactase deficiency, then the amount of related sugars should be taken into consideration: Duphalac liquid contains up to galactose 1.7 g and up to lactose 1 g per 15 mL.
The dose normally used in constipation should not pose a problem for diabetics. The dosage in the treatment of (pre) coma hepaticum is usually much higher and may pose a problem for diabetics.
Effects on the Ability to Drive or Operate Machinery: When taken as prescribed, Duphalac does not influence the ability to drive or operate machines.
Use in pregnancy & lactation: Duphalac may, on the basis of current knowledge, be safely used as instructed during pregnancy and lactation.
Duphalac may, on the basis of current knowledge, be safely used as instructed during pregnancy and lactation.
Flatulence may occur during the first few days of treatment. As a rule, it disappears after a couple of days. When dosages higher than instructed are used, belly ache and diarrhoea may occur. In such case, the dosage should be decreased. If high doses (normally only associated with PSE) are used for an extended period of time, the patient may experience an electrolyte imbalance due to diarrhoea.
Incompatibilities: Due to lactulose's mode of action of lowering the pH in the colon, drugs that have a colon pH-dependent release (eg, 5-acetylsalicylic acid agents) may be inactivated.
Store below 20°C. Do not freeze. Protect from direct sunlight.
A06AD11 - lactulose ; Belongs to the class of osmotically acting laxatives.
Oral soln 667 mg/mL x 200 mL.