Liquid lactulose is a popular laxative drug. Chemically, it is a synthetic disaccharide (galactose combined with fructose), absorbs very little from the gastrointestinal tract.
Lactulose action
Lactulose is broken down in the colon (mainly by bacteria from the Lactobacillus and Bacteroides families) into lactic acid, formic acid, acetic acid and carbon dioxide. These acids lower the pH in the colon and have a local osmotic effect, causing the colon to retain water.
As a result, the fecal mass is loosened and the intestinal peristalsis is stimulated. In patients with hepatic encephalopathy, lactulose reduces the concentration of ammonia in the blood.
Lactulose indications
Lactulose is used mainly because of chronic constipation and in situations where it is necessary to soften the stool for medical reasons (e.g. haemorrhoids). However, it is also used in encephalopathy in the course of hepatic failure.
Contraindications to the use of lactulose
Lactulose must not be used in the case of allergy to this active substance and in the case of gastrointestinal obstruction or the risk of its perforation.
The drug is also contraindicated in the case of rare hereditary problems of galactose or fructose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption.
Available preparations
The drug is available in the form of a syrup and can be obtained without a doctor's prescription (OTC drug).
Lactulose dosage
The initial dose (for the first three days) is 45 ml of the syrup (22.5 g of liquid lactulose) a day, used once before breakfast or 15 ml three times a day before meals.
The maintenance dose is 15 ml of syrup (7.5 g of liquid lactulose) on an empty stomach.
The drug can be used in children, in accordance with the dosage recommended by the manufacturer or determined by the pediatrician.
The laxative effect may take 2 to 10 hours. Lactulose solution can be administered diluted or undiluted. However, you should remember to drink plenty of fluids during the therapy.
A medical consultation is recommended in case of an unsatisfactory therapeutic effect after a few daysuse of lactulose.
Lactulose side effects
Lactulose can cause abdominal pain with gas and cramps. Consumption of high doses or long-term use of the drug causes loose stools and may lead to fluid and electrolyte imbalance.
Interaction with other drugs
- Since lactulose lowers the pH in the colon, drugs with a pH-dependent release may be inactivated.
- Lactulose enhances the effect of anticoagulants.
- Lactulose may increase potassium loss caused by other medications (diuretics and corticosteroids).
- Lactulose may also increase the effects of cardiac glycosides.
Pregnancy and breastfeeding
No adverse effects on pregnancy or the breastfed child are anticipated as systemic exposure to lactulose is low.
Impact on driving
The drug has no influence on the ability to drive and use machines.
Storing medicine
The drug should be stored in accordance with the manufacturer's instructions in the package insert. You should pay particular attention to the expiry date of the syrup from the first opening.