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Medically reviewed by Last updated on Apr 3, 2023.


(LAK ti tol)

Index Terms

  • Lactitol Monohydrate
  • Pizensy

Pharmacologic Category

  • Ammonium Detoxicant
  • Laxative, Osmotic


Simple monosaccharide sugar; produces laxative effect in colon by causing water influx into small intestine.




Feces (minimal).

Half-Life Elimination

2.4 hours.

Use: Labeled Indications

Chronic idiopathic constipation: Treatment of chronic idiopathic constipation (CIC) in adult patients.

Off Label Uses

Hepatic encephalopathy, prevention

Data from a limited number of patients in a randomized, controlled study suggest lactitol may be beneficial in the prevention of recurrent portal systemic encephalopathy in cirrhotic patients with portal-systemic shunt [Riggio 1989].

Based on the American Association for the Study of Liver Disease (AASLD) guidelines for the treatment of hepatic encephalopathy in chronic liver disease, nonabsorbable disaccharides (including lactitol) are not routinely recommended for primary prevention of overt hepatic encephalopathy, except in known high-risk cirrhosis patients. In addition, they are not routinely recommended for prevention of posttransjugular intrahepatic portosystemic shunt hepatic encephalopathy. However, use is recommended as secondary prevention after an initial episode of overt hepatic encephalopathy.

Hepatic encephalopathy, treatment

Data from randomized, double-blind, controlled trials; randomized crossover studies; and meta-analyses support the use of lactitol for the treatment of acute and chronic recurrent portal systemic encephalopathy [Gluud 2016], [Mas 2003], [Morgan 1987a], [Morgan 1987b]. Data from a randomized, controlled study and a randomized, crossover study suggest lactitol may be used in the management of minimal portal systemic encephalopathy to decrease ammonia levels and improve psychometric tests [Morgan 1989], [Salerno 1994].

Based on the AASLD guidelines for the treatment of hepatic encephalopathy in chronic liver disease, nonabsorbable disaccharides (including lactitol) are recommended as treatment for overt hepatic encephalopathy. Lactitol is not recommended for routine treatment of minimal hepatic encephalopathy; however, use may be considered on an individualized basis to help improve quality of life.


Mechanical GI obstruction (known or suspected); galactosemia

Dosing: Adult

Chronic idiopathic constipation: Oral: 20 g once daily; may reduce dose to 10 g once daily for persistent loose stools.

Hepatic encephalopathy, prevention of recurrence after portal-systemic shunt (off-label use): Oral: Initial: 0.5 g/kg/day in 2 divided doses; adjust dose to achieve 2 soft stools per day (Riggio 1989).

Hepatic encephalopathy, treatment (off-label use): Oral: 0.5 g/kg/day in 4 divided doses; adjust dose to achieve 2 to 3 soft stools per day (Morgan 1987a; Morgan 1987b; Vilstrup 2014 [AASLD]). Note: Lower doses of 0.3 g/kg once daily or 0.5 g/kg/day in 2 divided doses may be considered in patients with minimal hepatic encephalopathy (Salerno 1994; Morgan 1989).

Dosing: Geriatric

Refer to adult dosing.


Multi-dose bottle: Use the measuring cap (bottle top) to measure prescribed dose. Dissolve contents in 4 to 8 ounces of water, juice, or other beverage (eg, coffee, tea, soda).

Unit-dose packets: Dissolve contents of packet(s) in 4 to 8 ounces of water, juice, or other beverage (eg, coffee, tea, soda).


Oral: Administration with meals is preferred; drink entire contents of glass. Administer oral medications at least 2 hours before or 2 hours after lactitol.


Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C to 30°C (59°F to 86°F).

Drug Interactions

Dichlorphenamide: Laxatives may enhance the hypokalemic effect of Dichlorphenamide. Monitor therapy

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

1% to 10%:

Cardiovascular: Increased blood pressure (3%)

Gastrointestinal: Flatulence (8%), diarrhea (4%), abdominal distention (3%), abdominal pain (3%), severe diarrhea (1%)

Genitourinary: Urinary tract infection (5%)

Neuromuscular & skeletal: Increased creatine phosphokinase in blood specimen (4%)

Respiratory: Upper respiratory tract infection (9%)

Postmarketing: Hypersensitivity reaction, pruritus, skin rash


Concurrent drug therapy issues:

• Absorption: May reduce the absorption of concomitantly administered oral medications. Administer oral medications at least 2 hours before or 2 hours after lactitol.

Monitoring Parameters

Bowel movement patterns.

Pregnancy Considerations

Lactitol has minimal systemic absorption.

Treatment of constipation in pregnant women is similar to that of nonpregnant patients, and medications may be used when diet and lifestyle modifications are not effective. In general, osmotic laxatives are not initial therapy and should be used with caution and only for short durations in pregnancy due to the risk of electrolyte abnormalities (Body 2016).

Patient Education

What is this drug used for?

• It is used to treat constipation.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Passing gas

• Common cold symptoms

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Persistent diarrhea

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.