Lactulose is a medication used to treat hepatic encephalopathy, a complication of cirrhosis. It works on your digestive system to reduce levels of toxins like ammonia. If you have cirrhosis, you may need to take lactulose long-term.

Cirrhosis is a condition where your liver has become severely scarred. This damage is permanent and greatly affects your liver’s ability to function properly.

The effects of cirrhosis can lead to several complications. One of these is hepatic encephalopathy (HE), a buildup of toxins in the brain.

HE can lead to problems with movement, sleep, and thinking and memory. According to the American Liver Foundation, about 70% of people with cirrhosis develop some signs of HE.

Lactulose is a medication used to treat HE in people with cirrhosis. Read on to learn more about how lactulose is used for cirrhosis.

One of the functions of your liver is to remove toxins from your blood. An example of one such toxin is ammonia, which the liver typically converts to urea. Urea leaves your body in your urine.

However, the liver doesn’t function well in people with cirrhosis. This means that toxins like ammonia cannot be removed from your blood as effectively.

When ammonia remains in the bloodstream, it can travel to the brain where it can be very harmful. Accumulation of ammonia in the brain leads to HE.

Lactulose is a synthetic sugar. In addition to treating HE in people with cirrhosis, it’s also Food and Drug Administration (FDA)-approved as a laxative to treat constipation.

Lactulose draws more water into your large intestine, softening stool and increasing the number of bowel movements you have. This laxative effect allows toxins to be more readily flushed from your body instead of being absorbed.

It also affects bacteria in your large intestine. Not only does it promote some of them to take up and break down ammonia, but it also lowers the pH in your large intestine, which has a negative impact on ammonia-producing bacteria.

There are two general types of HE. These are covert and overt HE.

In covert, or minimal HE, there are few physical symptoms, but issues with thinking and memory may be observed. In overt HE, additional symptoms like problems with movement, inappropriate behavior, and disorientation are present.

Lactulose has many benefits for people with cirrhosis who have either type of HE. According to a 2023 review, lactulose can:

  • reverse covert HE
  • prevent progression to overt HE
  • boost recovery from overt HE
  • reduce mortality (chance of death)
  • improve quality of life

Most of the side effects of lactulose impact the digestive system. These include:

If diarrhea is persistent or severe, it can lead to complications like dehydration and electrolyte imbalances.

Lactulose is prescribed to people with cirrhosis who have signs of HE. Generally speaking, a doctor may use the following to help diagnose HE:

  • a thorough medical history and physical exam
  • tests that assess cognitive and motor function
  • blood tests
  • imaging

There are some people who may not be able to take lactulose for cirrhosis. When a factor prohibits you from safely taking a medication, it’s referred to as a contraindication.

Lactulose contains the sugar galactose. Due to this, needing to be on a low-galactose diet is a contraindication for lactulose.

Other groups of people for which lactulose may need to be used with more caution include:

  • older adults
  • pregnant people
  • people with diabetes

The dose of lactulose you receive can depend on the severity of HE. People with severe HE symptoms will need to take lactulose more frequently.

In general, 30 to 45 milliliters (mL) of lactulose is typically given up to four times a day for people with HE. The aim is to achieve two to three soft stools each day.

If you have severe HE symptoms, hourly doses of up to 45 mL of lactulose may be used. After symptoms have resolved, you can then receive the typical recommended dose of lactulose described above.

How long should you take lactulose for liver disease and cirrhosis, and when should you stop?

Your doctor can give you a better idea of how long you’ll need to take lactulose. Generally speaking, you may need to take it for many months if you’ve had HE.

Prescribing information notes that continuous, long-term treatment with lactulose can help to reduce the severity of HE or prevent a recurrence of HE.

How does lactulose decrease ammonia?

Lactulose lowers ammonia by acting through the digestive system. It does this by increasing the number of bowel movements and boosting ammonia uptake by some gut bacteria while reducing the number of ammonia-producing gut bacteria.

What is the best medication for cirrhosis?

There is no single best medication for cirrhosis. If you have cirrhosis, the medications that will be recommended to you will depend on your symptoms and the complications you’re experiencing.

Lactulose is a medication that’s used to treat HE, a complication of cirrhosis. HE happens due to the buildup of toxins like ammonia in the brain, which can lead to problems with sleep, movement, thinking, and memory.

You typically take lactulose as an oral solution. It acts on the digestive system in several ways to reduce ammonia levels, easing the symptoms of HE.

Lactulose has many benefits for HE but does have some risks and contraindications. You may also need to take it for several months. Be sure to discuss these topics with your doctor before taking lactulose.