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URL of this page: https://medlineplus.gov/druginfo/meds/a682338.html

Lactulose

pronounced as (lak' tyoo lose)

Why is this medication prescribed?

Lactulose 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. Lactulose is also used to reduce 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.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Lactulose comes as liquid to take by mouth. It usually is taken once a day for treatment of constipation and three or four times a day for liver disease. Your prescription label tells you how much medicine to take at each dose. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take lactulose exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

What special precautions should I follow?

Before taking lactulose,

  • tell your doctor and pharmacist if you are allergic to lactulose or any other drugs.
  • Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking lactulose. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.The following nonprescription products may interact with lactulose: antacids, neomycin, and other laxatives. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking lactulose. Do not start any of these medications while taking lactulose without discussing with your healthcare provider.
  • tell your doctor if you have diabetes or require a low-lactose diet.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking lactulose, call your doctor.
  • if you are having surgery or tests on your colon or rectum, tell the doctor that you are taking lactulose.

What should I do if I forget a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

Lactulose may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • diarrhea
  • gas
  • nausea

If you have any of the following symptoms, stop taking lactulose and call your doctor immediately:

  • stomach pain or cramps
  • vomiting

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

What other information should I know?

Keep all appointments with your doctor.

To improve the taste of lactulose, mix your dose with one-half glass of water, milk, or fruit juice.

Do not let anyone else take your medicine. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

  • Cholac®
  • Constilac® Syrup
  • Constulose®
  • Enulose®
  • Evalose® Syrup
  • Generlac®
  • Heptalac®
  • Kristalose®
  • Laxilose®
  • Portalac®

This branded product is no longer on the market. Generic alternatives may be available.

Last Revised - 01/15/2024