Lactulax: Uses, Side Effects, Interactions, Administration and Warnings

It is indicated for the treatment of chronic constipation in patients with predisposing factors and with disorders associated with constipation:

  • Irritable bowel syndrome.
  • Diverticular disease.
  • Psychogenic constipation.

Also, as preventive medicine for patients who should not make any effort when defecating:

  • Hemorrhoids, abscesses, perianal fissures, diaphragmatic hernia, abdominal wall herniation, anorectal stenosis, cerebrovascular disease in the postpartum period, and patients in recovery, surgery, and after myocardial infarction.

Lactulax relieves constipation by introducing water into the intestine to soften the poop. The most common side effects are diarrhea, bloating, and wind.

Lactulax takes at least 48 hours to work. If you find that the taste of Lactulax is too sweet, you can dilute it with fruit juice or water.

Lactulax is a laxative that is taken to treat constipation (difficulty with pooping). It is also taken to help a severe liver disease called hepatic encephalopathy.

Lactulax comes as a sweet syrup that you swallow. It is available by prescription and to buy in pharmacies.

How Lactulax works

Lactulax is a synthetic (artificial) sugar. It breaks down in the large intestine and then draws water into the intestine. This softens the stool, which helps relieve constipation.


High ammonia levels can lead to portal-systemic encephalopathy. This medicine works by drawing ammonia from the blood into the large intestine. Your large intestine then removes the ammonia through your stool.

Side effects of Lactulax

Like all medications, Lactulax can cause side effects in some people, but many people have no or only mild side effects.

Lactulax oral solution does not cause drowsiness. The most common side effects. The most common side effects of Lactulax can include:

  • Belching
  • Gas.
  • Nausea.
  • Cramps in any part of the body.

A widespread side effect, particularly in high doses, is diarrhea. This happens in more than 1 in 10 people.

Other common side effects, which occur in more than 1 in 100 people, are:

  • Swelling.
  • Feeling sick.
  • Barf.
  • Stomach ache.

These side effects are mild and usually go away after a few days. Tell your doctor or pharmacist if the side effects bother you or do not disappear.

Serious side effects

Tell your doctor right away if these unlikely but severe side effects occur. Serious side effects and their symptoms may include the following:

  • Severe diarrhea or vomiting can cause dehydration (deficient water levels in your body).
  • Muscle cramps or weakness
  • Irregular heartbeat
  • Vomiting

Call your doctor right away if you have serious side effects. Call 911 if your symptoms are life-threatening or if you think you have a medical emergency.

To help avoid interactions, your doctor should handle all of your medications with care. These effects can go away in a few days to a couple of weeks if they are mild.

Diarrhea Warning: This drug can cause diarrhea and lead to severe dehydration. Call your doctor immediately if you have severe diarrhea while taking this medicine.

Galactose and Lactose Warning: This medicine contains galactose and lactose (milk sugars). Ask your doctor if this medicine is safe for you, if you are lactose intolerant, if you are on a low galactose diet, or if you have diabetes.

Allergy warning

In rare cases, Lactulax can cause a severe allergic reaction. Warning signs and symptoms of a severe allergic reaction can include:

  • Difficulty breathing (wheezing).
  • Swelling of your throat or tongue (swelling of the mouth, face, lips, tongue, or throat).
  • A skin rash may include itching, redness, swelling, blistering, or peeling.
  • Tightness in the chest or throat.
  • Having trouble speaking

These are not all the side effects of Lactulax. For a complete list, see the leaflet inside the drug package.

You can report any suspected side effects to the UK security scheme.

Call your doctor or local poison control center immediately if you have an allergic reaction. Retaking it could be fatal (cause death).

How to deal with side effects

What to do about it:

Bloating: take Lactulax between meals rather than before or after meals

Gas – Avoid wind-causing foods like legumes, lentils, beans, and onions.

Eating smaller, more frequent meals, eating and drinking slowly, and exercising regularly can help. Some drugstore remedies help the wind, such as charcoal or simethicone tablets.

Feeling sick: try taking Lactulax with meals or mix your dose with a bit of water or fruit juice.

Vomiting – Drink lots of water or other fluids. It can also help to take oral rehydration solutions that you can buy from a pharmacy to prevent dehydration.

Do not take other medications to treat vomiting without talking to a pharmacist or doctor.

Interactions with Lactulax

There are no known problems when mixing Lactulax with other medications, herbal remedies, or supplements.

However, for your safety, tell your doctor or pharmacist if you are taking any other medications, including herbal remedies, vitamins, or supplements.

Medications you should not use with Lactulax.

Do not take these medications with Lactulax. Examples of drugs that can cause interactions with Lactulax are listed below:

Antacids: You should not take antacids with Lactulax. Antacids can stop Lactulax from working well.

Interactions that can make your medications less effective

When used with Lactulax, these medications can make Lactulax less effective. This means that it will not work as well to treat your condition. Examples of these medications include:

Antibiotics such as neomycin: These drugs can stop the breakdown of Lactulax in your large intestine. Your doctor will watch you closely if you take Lactulax with an antibiotic.

Always talk to your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs, supplements, and the over-the-counter medications you are taking.

Lactulax overdose

If you or someone you know has an overdose, call your local emergency number, or you can contact your local poison control center directly by calling the national toll-free number.

Lactulax overdose symptoms

  • Low blood sugar
  • Eruption.

Sodium phosphate :

  • Abdominal pain.
  • Fainting.
  • Diarrhea.
  • Muscular weakness.
  • Threw up.

Products containing magnesium :

  • Abdominal pain.
  • Fainting.
  • Coma.
  • Death.
  • Diarrhea (watery)
  • Decreased blood pressure.

Poisonous elements

Overuse of these medications can cause laxative overdose symptoms:

  • Bisacodyl.
  • Carboxymethylcellulose.
  • Cascara sagrada.
  • Casantranol.
  • Beaver oil.
  • Dehydrocholic acid.
  • Glycerin.
  • Magnesium citrate.
  • Magnesium hydroxide.
  • Magnesium oxide.
  • Magnesium sulfate.
  • Malt soup extract.
  • Methylcellulose
  • Milk of magnesia.
  • Mineral oil.
  • Fenolftaleína.
  • Poloxamer 188.
  • Polycarbophil.
  • Potassium bitartrate and sodium bicarbonate.
  • Sodium phosphate.

Other laxative products may also cause an overdose.

Lactulax administration

This dosage information is for Lactulax oral solution. All possible doses and forms of drugs may not be included here. Your amount, form of medicine, and how often you take medicine will depend on:

  • Your age.
  • The condition that is being treated.
  • How serious is your situation?
  • Other medical conditions you have.

Dosage for constipation

The usual dose for constipation in:

  • Adults and children 14 years and older have 15 to 45 ml once or twice a day; this dose can be reduced to 15-30 ml once or twice a day after it starts working.
  • Children between 7 and 14 years old pay 15 ml once or twice a day; This dose can be reduced to 10-15 ml once or twice a day after it starts to work.
  • Children 1 to 6 years (only under medical supervision) have 5 to 10 ml once or twice daily.
  • Babies under one year (only under medical supervision) can receive up to 5 ml once or twice daily.
  • The usual dose for adults with hepatic encephalopathy is between 30 and 45 ml. It was taken 3 to 4 times a day.

This medicine has not been confirmed to be safe and effective in children under 18 years of age for the treatment of constipation.

Dosage Warnings: If your child’s first dose causes diarrhea, their dose should be reduced by their doctor immediately. If diarrhea continues, your doctor will likely stop taking this medicine.

Dose adjustments: Your doctor may adjust your dose every day or every other day until you can produce two or three loose stools per day.

Take as indicated

The medicine comes with a plastic cup or spoon to measure your dose. Please do not use a kitchen spoon as it will not give you the correct amount. Ask your pharmacist for one if you don’t have a cup or spoon.

Some people do not like the sweet taste of Lactulax. You can mix your dose with half a glass of water or fruit juice to improve the like.

Try to drink 6 to 8 glasses of fluids during the day while taking Lactulax, or your constipation may worsen.

Lactulax is used for the short-term treatment of constipation. It is used for the short-term or long-term treatment of portal-systemic encephalopathy. It comes with serious risks if you don’t take it as prescribed.

What to do if you miss a dose: Take your amount as soon as you remember. If you miss a dose of Lactulax, don’t worry; take the next dose at the usual time.

Never take two doses at the same time. Never take an extra amount to make up for a missed one.

If you often forget doses, it may be helpful to set the alarm to remind you. You can also ask your pharmacist for advice on other ways to help you remember to take your medicine.

What if I take too much: Taking an extra dose of Lactulax by accident is unlikely to harm you. You may have diarrhea and stomach pain, but this should subside in a day or two.

How to know if the drug is working

For constipation, you need to start having regular bowel movements. It may take 24 to 48 hours for this medicine to work, but sometimes it does not start working for 48 hours or more.

You should have two or three loose stools a day. The high levels of ammonia caused by the condition are flushed out of your body through your sweat. Take this medicine at the time (s) recommended by your doctor.


Store Lactulax in the refrigerator at room temperature. Keep it between 36 ° F and 86 ° F (2 ° C and 30 ° C). Do not freeze this medicine.


You can mix Lactulax with a small amount of fruit juice, water, or milk if necessary. Drink the mixture right away. Don’t save it for later. Take Lactulax once or twice a day. You can take it with or without food.

Clinical follow-up

Your doctor may perform blood tests to check your electrolyte levels during your treatment with this medicine. Your doctor can do this if you have taken this medicine for more than six months.

This monitoring can help ensure that your levels are within the range your doctor considers best for you, with the least risk of side effects.


Many insurance companies require prior authorization for this drug. This means that your doctor may need to get approval from your insurance company before the insurance company pays for the prescription.


For people with problems digesting galactose: This medicine contains galactose (milk sugar). Ask your doctor if this medicine is safe for you.

For people with diabetes: This drug can increase your blood sugar levels. Ask your doctor if this medicine is safe for you.

For pregnant women: constipation is expected late in pregnancy and right after having a baby. Lactulax is generally safe during pregnancy and while breastfeeding.

But, Lactulax is a category B pregnancy drug. That means two things:

Animal research has not shown a risk to the fetus when the mother takes the drug.

There are not enough human studies to show whether the drug risks the fetus.

Animal studies don’t always predict how humans would respond. Therefore, this drug should only be used in pregnancy if necessary.

Your doctor or midwife will advise you to eat more fiber and drink plenty of fluids. For safety, tell your pharmacist or doctor if you are trying to get pregnant, are already pregnant, or are breastfeeding.

For breastfeeding women: Lactulax can pass into breast milk and cause side effects in a breastfed child.

Talk to your doctor about breastfeeding your child. You may need to decide whether to stop breastfeeding or stop taking this medicine.

For children: This medicine has not been confirmed to be safe and effective for treating constipation in children under 18.

If your child is taking this medicine for complications of liver disease, his doctor will monitor him closely during treatment to ensure he has at least two to three loose stools each day.

This is because ammonia is flushed out of your child’s body through stools. Your child’s doctor will also watch for side effects like diarrhea.

Who can and cannot take Lactulax

Lactulax is not suitable for some people. To make sure Lactulax is safe for you, tell your doctor or pharmacist if:

  • You have ever had an allergic reaction to Lactulax or any other medicine in the past. You are lactose intolerant (where your body cannot digest the sugar or lactose).
  • You have galactosemia (a rare health problem in which the body cannot process a sugar called galactose). You have diabetes (as Lactulax can affect your blood sugar levels).