Lactulose: uses, dosing, side effects & brands

Key facts

Frequently asked questions

What is lactulose?

Lactulose is a synthetic disaccharide in solution form for oral administration. Each 15 mL of lactulose solution, USP contains: 10 g lactulose (and less than 1.6 g galactose, less than 1.2 g lactose, and 0.1 g or less of fructose). Lactulose is a colonic acidifier which promotes laxation. The chemical name for lactulose is 4-O- β -D-galactopyranosyl-D-fructofuranose. It has the following structural formula: The molecular weight is 342 . 30. It is freely soluble in water. 3bfff862-figure-01

What kind of drug is lactulose?

The FDA classifies lactulose as an osmotic laxative. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

Can you take lactulose with other medicines?

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run lactulose against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

What brand names is lactulose sold under?

We track 3 lactulose-containing products in the U.S.: Lactulose, Cephulac and Chronulac. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.

What forms does lactulose come in?

Across the brands we track, lactulose is currently marketed as solution and powder, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Is there a generic lactulose?

Yes. Our catalog lists 1 generic lactulose product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.