Lactulose

Benjamin Clanner-Engelshofen is a freelance writer in the medical department. He studied biochemistry and pharmacy in Munich and Cambridge / Boston (USA) and noticed early on that he particularly enjoyed the interface between medicine and science. That is why he went on to study human medicine.

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The active ingredient lactulose (lactulose) is a synthetically produced double sugar (disaccharide) and is used as a laxative. Since it cannot be digested and absorbed into the body, its use generally rarely leads to side effects. Here you can read everything you need to know about lactulose, its effects and side effects.

This is how the active ingredient lactulose works

Lactulose is produced as a double sugar from milk sugar (lactose). In contrast to lactose, it is indigestible and therefore remains in the intestine. This draws water into the intestines, which softens the intestinal contents. In the large intestine (colon), the laxative can partially be broken down by the bacteria located there. The resulting breakdown products (lactic acid, acetic acid and other organic acids) stimulate bowel movement and thereby facilitate bowel movements.

Another, but rarely used, effect of these acids, which are produced during the breakdown of lactulose, is that they create a more acidic environment in the intestine. This is of advantage in the case of certain liver diseases: If the liver can no longer fulfill its detoxification function, toxic metabolic products such as ammonia accumulate in higher concentrations in the blood. This is bound by the acidic environment in the large intestine and thus effectively removed from the blood.

Breakdown and excretion of lactulose

After taking the laxative, only about half to two percent of the total amount of active ingredient is absorbed into the blood through the intestine. This portion is excreted unchanged via the kidneys with the urine. The laxative effect, with which the active ingredient leaves the body, usually occurs after two to ten hours.

When is lactulose used?

Lactulose is used for constipation that cannot be adequately improved by a high-fiber diet and other general measures (adequate fluid intake, balanced diet, etc.).

The active ingredient is also given in situations that require easier bowel movements, such as after operations on the rectum or in the case of rectal ulcers.

Lactulose is also used in the prevention and treatment of so-called "portocaval encephalopathy", a liver disease in which ammonia blood levels are increased.

The application can be one-time, short-term or long-term.

This is how lactulose is used

The active ingredient is marketed in the form of lactulose syrup (or lactulose juice) or as a powder. Both dosage forms can be mixed in liquid or taken undiluted, but sufficient liquid should always be drunk with it (at least one and a half to two liters daily). If the intake is planned over a longer period of time, it should always take place at the same time each day. It is taken independently of meals. The maximum lactulose dosage should not exceed 30 grams per day.

What are the side effects of lactulose?

In more than every tenth person treated, lactulose side effects such as abdominal pain, flatulence, nausea, vomiting and diarrhea occur, especially at the beginning of therapy. The severity of the side effects depends on the level of the dosage. With long-term use, disturbances in the area of ​​the water and electrolyte balance must be expected.

What should be considered when taking lactulose?

Some drugs trigger a loss of potassium as a side effect, for example dehydrating agents, cortisone derivatives and amphotericin B (anti-fungal agents). The laxative can increase this side effect.

In the case of drugs with a delayed release of active ingredients (so-called sustained release drugs), the effect can be shortened, as lactulose accelerates the passage through the intestines.

The laxative should not be used in acute inflammatory gastrointestinal diseases or disorders in the water and electrolyte balance.

Medicines containing the active ingredient lactulose can be used during pregnancy, breastfeeding and in the elderly.

Use in children should be the exception and be monitored by a doctor.

How to get medicines with lactulose

Medicines with the active ingredient lactulose are only available from pharmacies, but are not subject to prescription. However, they can be prescribed for certain underlying diseases at the expense of the statutory health insurance.

Since when has lactulose been known?

In 1930 it was first described that lactulose is formed from milk sugar (lactose) when heated. In 1956 the doctor Friedrich Petuely was able to prove that the administration of lactulose leads to an increased number of certain lactobacilli in the stool and thus could alleviate the side effects of broad-spectrum antibiotics. He also discovered the laxative effect of lactulose. In the 1960s, the laxative finally came onto the market in Europe.

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