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What is Evalax and what is it used for?

Evalax contains Lactulose 10 g/15 ml in liquid (solution) form. It is a laxative and a non-absorbable sugar. It is used for following indications:


1.      Constipation

2.      Hepatic Encephalopathy


How does it work?

Evalax is a synthetic sugar used to treat constipation. It is broken down in the colon into products that pull water out from the body and into the colon. This water softens stools.

It is also used to treat hepatic encephalopathy by reducing the amount of ammonia in the blood of patients with liver disease. It works by drawing ammonia from the blood into the colon where it is removed from the body.


How to take Evalax?

Please do not give Evalax to children before consulting your doctor for prescription and careful supervision.


Starting Dose

Maintenance Dose

Adolescents (over 14 years)

15-45 ml daily corresponding

to 10-30 gm lactulose

15-30 ml daily corresponding

to 10-20 gm lactulose

Children (7-14 years)

15 ml daily corresponding

to 10 gm lactulose

15 ml daily corresponding

to 10 gm lactulose

Infants, toddlers and children up to 6 years, take lactulose if their doctor recommends it.

It can be taken with or without food.

What if you miss a dose?

If you forget to take a dose of Lactulose, do not worry. Just take the next dose at the usual time. Do not take a double dose to make up for a forgotten dose.      


What to do in case of overdose?

In case of overdosage, you may experience diarrhoea and abdominal pain. Contact your doctor or pharmacist if you have taken more Lactulose than you should.


What do you need to know before you take Evalax?

Do not take Evalax:

·         if you are allergic to lactulose or any of the other ingredients of this medicine

·         if you suffer from galactosaemia, acute inflammatory bowel disease (like Crohn’s disease or ulcerative colitis), blockage in your  bowel (apart from normal constipation), digestive perforation or risk of digestive perforation or unexplained abdominal pain.


Warning and Precautions

Talk to your doctor or pharmacist before taking Evalax:

·         Please tell your doctor before taking Lactulose if you suffer from gastro-cardiac syndrome (Roemheld syndrome).

·         If you have symptoms like excess gas in your bowels or bloating after using it, stop the treatment and consult your doctor.

·         Long-term use of unadjusted dosages (exceeding 2-3 soft stools per day) or misuse can lead to diarrhea and disturbance of the electrolyte balance.

·         If you are an elderly patient or a patient in bad general condition and take lactulose for a more than 6 months period, your doctor will regularly check your blood electrolytes.

·         During the treatment with laxatives you should drink sufficient amounts of fluids (approx. 2 litres per day, equal to 6-8 glasses)


Evalax and other medications

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicine.


Pregnancy and breast-feeding

Lactulose is generally safe to take during pregnancy and while breastfeeding. Constipation is common at the end of pregnancy and just after having a baby. If you’re pregnant or breastfeeding, it’s always better to try to safely treat constipation without taking a medicine. Consult your doctor before its administration.


Driving and using machines

Evalax will not affect your ability to drive safely or use machines.


What are the possible side effects?

Common side-effects are: diarrhea, nausea, vomiting, bloating, gas, belching, and stomach pain or discomfort.

Mechanism of action:

Lactulose is a man-made sugar that contains two naturally occurring sugars, galactose and fructose. It is not digested in the intestine like other sugars so that it reaches the colon where bacteria digest it and thereby alter the composition of the stool.

Lactulose is used as a laxative to treat constipation. In the colon, lactulose is broken down by bacteria into products that help to draw water into the colon, which softens the stool.


Additionally, lactulose is used to treat hepatic encephalopathy, a loss of brain function and change in mentation that occurs when the liver is unable to remove toxins from the blood. Bacteria in the colon digest lactulose into chemicals that bind ammonia that is believed to be the toxin that causes hepatic encephalopathy. The binding of ammonia prevents ammonia from moving from the colon into the blood and also draws ammonia from the blood and into the colon. The bound ammonia then is removed from the body in the stool.


Pharmacokinetic properties:

Absorption:  After administration by the oral route, less than 3% of the given dose of lactulose solution is absorbed by the small intestine. The remaining unabsorbed lactulose reaches the large intestine where it is metabolized – but even then, negligible quantities of unchanged lactulose or its metabolites are absorbed across the colon.

Volume of Distribution: Negligible amounts of lactulose – metabolized or non-metabolized – are absorbed into the body. Most lactulose that is administered subsequently remains predominantly around the gastrointestinal tract area.

Protein Binding: Negligible amounts of lactulose – metabolized or non-metabolized – are absorbed into the body. Regardless, data regarding the protein binding of lactulose is not readily available or accessible.

Metabolism:  Lactulose is essentially only metabolized in the colon by saccharolytic bacteria that are present there. In particular, the substance is broken down into lactic acid and small amounts of acetic and formic acid

Excretion: The renal excretion of any lactulose that manages to be absorbed into the circulation has been determined to be 3% or less and is generally complete within 24 hours. Any unabsorbed lactulose is largely excreted with stool.

Elimination Half-life:  The data regarding the half-life of lactulose is not readily available or accessible.


Evalax and other medicines

·         Lactulose may increase the loss of potassium caused by other drugs (e.g. thiazides, steroids and amphothericin B).

·         Use of cardiac glycosides (e.g. digoxin) along with Lactulose can increase the effect of the glycosides by decreasing potassium in the blood.

With increasing dosage a decrease of pH-value in the colon is found. Therefore drugs which are released in the colon pH-dependently (e.g. 5-ASA) can be inactivated.