Macrogol: Formula, Presentation, Indications, Mechanism of Action, Dosage, Side Effects, Warnings, Contraindications and Interactions

It is a medicine that belongs to the drugs called osmotic laxatives.

Macrogol generally works 24 to 48 hours after you administer it.

This medicine is in the form of a powder that must be dissolved in a glass with a content of at least 50cc of water.

The improvement in intestinal transit after taking macrogol can be maintained by adopting a new lifestyle and a healthy diet.

Chemical formula of macrogol

  • It contains the active ingredient macrogol (H– (OCH 2 CH 2) n –OH).


Its presentation for sale is in sachets, which can be dissolved in any liquid, making it easier for children to take it.


Macrogol treatment is indicated for chronic constipation, from 2 years of age.

It is also recommended for fecal impaction in children older than 5 years, which is also known as refractory constipation , either with fecal load from the rectum or the colon.

Mechanism of action

Macrogol has its effects thanks to the osmotic action in the intestine that increases the volume of the stool, and consequently causes the motility of the colon through the neuromuscular pathway.

As a physiological consequence, there is an improvement in the propulsive colonic transport of softened stools, which facilitates defecation.

Macrogol supports the increase in the amount of water in the stool, which favors the resolution of problems related to slow intestinal transit.

Macrogol is not absorbed into the bloodstream and is not modified in the body.


In children

In cases of chronic constipation , it is started with a dose of 1 sachet daily for children aged 2 to 6 years and for children aged 7 to 11 years, the dose is 2 sachets daily .

The dose should be adjusted to achieve regular loose stools, over or under as needed.

The dose should be increased every two days, taking care not to exceed a maximum dose of 4 sachets per day.

In children older than 12 years and adults

The recommended dose is 1 to 3 sachets a day, which should be administered preferably in the morning.

The daily dose can be adapted to the effect obtained and can vary from 1 out of every 2 days (in children in particular).

Macrogol side effects

Cases of allergic reactions manifested by skin rash and swelling of the face or throat ( angioedema ) have been reported in adults after taking medicines containing macrogol (polyethylene glycol).

Isolated cases of severe allergic manifestations causing loss of consciousness, collapse or breathing difficulties and feelings of general malaise have been reported.

The most common side effects were diarrhea , abdominal pain, nausea, vomiting, and anal itching, as this medicine can sometimes cause diarrhea.

Warnings and Contraindications

In children, the duration of treatment with macrogol should not exceed 3 months.

Macrogol should not be administered if you are allergic to macrogol or any of the components of the formula.

Macrogol should not be given when you have a serious intestinal disease, such as:

  • Inflammation of the intestine (such as ulcerative colitis , Crohn’s disease, abnormal intestinal dilation).
  • Bowel perforation or risk of intestinal ileus perforation.
  • When there are signs of a blockage in the intestines.
  • When the patient has abdominal pain whose cause is unknown.

Treatment for chronic constipation in children under 12 years of age should be prolonged for at least 6 months to a year.

When macrogol treatment is to be terminated, this should be done gradually.

In cases of fecal impaction, the treatment cycle lasts up to 7 days and must be discontinued once the impaction is removed.

In cases of impaired cardiovascular function and kidney failure, macrogol is not recommended for the treatment of fecal impaction in children aged 2 to 11 years.

In children older than 12 years with impaired cardiovascular function, the dose should be divided in the treatment of fecal impaction, but not in cases of renal failure, for children of the same age.

Macrogol interactions

This drug may interact in patients who are taking diuretics (drugs for urinary excretion) or in patients who have a decrease in sodium and potassium levels in the blood.

It is likely to affect the absorption of other drugs.