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Last reviewed on RxList: 1/26/2017
Constulose Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 01/26/2017

Constulose (lactulose solution) is a colonic acidifier which promotes laxation indicated for the treatment of constipation. Common side effects of Constulose include:

  • temporary gas and intestinal cramps,
  • diarrhea,
  • nausea, and
  • vomiting.

The usual dose of Constulose is 1 to 2 tablespoonfuls (15 to 30 mL, containing 10 g to 20 g of lactulose) daily. The dose may be increased to 60 mL daily if necessary. Twenty-four to 48 hours may be required to produce a normal bowel movement. Constulose may interact with antacids. Tell your doctor all medications and supplements you use. Tell your doctor if you are pregnant or plan to become pregnant before using Constulose; it is unknown if it will affect a fetus. It is unknown if Constulose passes into breast milk. Consult your doctor before breastfeeding.

Our Constulose (lactulose solution) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Constulose Professional Information


Precise frequency data are not available.

Initial dosing may produce flatulence and intestinal cramps, which are usually transient. Excessive dosage can lead to diarrhea with potential complications such as loss of fluids, hypokalemia, and hypernatremia.

Nausea and vomiting have been reported.

Read the entire FDA prescribing information for Constulose (Lactulose Solution, USP 10 g/15 mL)


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© Constulose Patient Information is supplied by Cerner Multum, Inc. and Constulose Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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