Get your patient on Lactulose - Lactulose solution (Lactulose)

For the treatment of constipation. In patients with a history of chronic constipation, lactulose solution therapy increases the number of bowel movements per day and the number of days on which bowel movements occur.

The usual dose 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.

Note: Some patients have found that lactulose solution may be more acceptable when mixed with fruit juice, water or milk.

Since lactulose solution contains galactose (less than 1.6 g/15 mL), it is contraindicated in patients who require a low galactose diet.

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.

To report SUSPECTED ADVERSE REACTIONS, contact Chartwell RX, LLC. at 1-845-232-1683 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

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 1.2 g or less of other sugars). Also contains water. The pH range is 2.5 to 6.5.

Lactulose is a colonic acidifier which promotes laxation.

The chemical name for lactulose is 4-O-β-D-galactopyranosyl-D-fructofuranose. The molecular formula is C ₁₂ H ₂₂ O ₁₁ . It has the following structural formula:

The molecular weight is 342.30. It is freely soluble in water.

Lactulose is poorly absorbed from the gastrointestinal tract and no enzyme capable of hydrolysis of this disaccharide is present in human gastrointestinal tissue. As a result, oral doses of lactulose reach the colon virtually unchanged. In the colon, lactulose is broken down primarily to lactic acid, and also to small amounts of formic and acetic acids, by the action of colonic bacteria, which results in an increase in osmotic pressure and slight acidification of the colonic contents. This in turn causes an increase in stool water content and softens the stool.

Since lactulose does not exert its effect until it reaches the colon, and since transit time through the colon may be slow, 24 to 48 hours may be required to produce the desired bowel movement.

Lactulose given orally to man and experimental animals resulted in only small amounts reaching the blood. Urinary excretion has been determined to be 3% or less and is essentially complete within 24 hours.

Lactulose Solution, USP is a colorless to amber syrupy liquid. It is available in

8 fl oz (237 mL) bottle (NDC 62135-002-37)

16 fl oz (473 mL) bottle (NDC 62135-002-47)

32 fl oz (946 mL) bottle (NDC 62135-002-94)

4 Quarts (3785 mL) bottle (NDC 62135-002-78)

15 mL Unit Dose Cups (NDC 62135-002-51)

20 Unit Dose Cups of 15 mL each (NDC 62135-002-24)

30 mL Unit Dose Cups (NDC 62135-004-43)

20 Unit Dose Cups of 30 mL each (NDC 62135-004-24)

Lactulose Solution, USP contains 667 mg/mL (10 g/15 mL).

Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature.] Do not freeze. Keep tightly closed.

Under recommended storage conditions, a normal darkening of color may occur. Such darkening is characteristic of sugar solutions and does not affect therapeutic action. Prolonged exposure to temperatures above 30°C (86°F) or to direct light may cause extreme darkening and turbidity which may be pharmaceutically objectionable. If this condition develops, do not use.

Prolonged exposure to freezing temperatures may cause change to a semi-solid, too viscous to pour. Viscosity will return to normal upon warming to room temperature.

Dispense in original container or in a tight, light-resistant container as defined in the USP, with a child-resistant closure.

Manufactured for:
Chartwell RX, LLC.
Congers, NY 10920

L72121

Rev: 01/2026