COMMON BRAND NAME(S): Cephulac, Enulose



Description: Lactulose promotes peristalsis by producing an osmotic effect in the colon w/ resultant distention. In hepatic encephalopathy, it reduces absorption of ammonium ions and toxic nitrogenous compounds, resulting in reduced blood ammonia concentrations.

  • Prevention of liver disease complications
  • May also be used for treating constipation

How to use lactulose

  • Always refer to your doctors instructions before taking this medication. Duration and dosage will be determined by your medical condition and its response to the medication. Make sure to take this medication in the prescribed amount and time period even after symptoms disappear. Discontinuing the medication before completion of treatment may cause incomplete treatment of condition. If Symptoms persist, consult your doctor.
  • Taken by mouth; May be mixed into into fruit juice, water, milk, or a soft dessert; usually 3-4 times a day or as directed by your physician; End goal is to have 2-3 soft stools each day.
  • If taken for constipation, take it usually once daily or as directed by your doctor.
  • May also be given rectally as an enema for liver disease. Mix the prescribed amount of lactulose with 700 milliliters (24 ounces) of water or normal saline and give the solution via the rectum and keep the liquid inside for 30-60 minutes as directed by your doctor.

Minor side effects (if these symptoms persist or worsen, inform your doctor)

  • Gas, bloating, burping, stomach rumbling/pain, nausea, and cramps may occur.

Serious side effects (inform your doctor immediately)

  • Diarrhea, vomiting, muscle cramps/weakness, irregular heartbeat, mental/mood changes, seizures.

Severe allergic reactions are rare. Get immediate medical help if you notice the following:

  • Rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.


  • Inform your doctor
    • Allergy to the medication or any allergies
    • Medical History of a low galactose diet (e.g., a diet that includes few or no milk products), certain other bowel problem (bowel obstruction), diabetes.
  • Do not take any laxative medications while using this drug as the combination may cause a severe loss of body water (dehydration) which is especially likely to occur in children or the elderly
    • Muscle weakness, muscle cramps, dizziness.

Before having surgery or other procedures (e.g., electrocautery), tell your doctor or surgeon that you are using this medication.

This medication contains different sugars. If you have diabetes, this medication may affect your blood glucose levels. Monitor your blood glucose regularly, and share the results with your doctor. Your anti-diabetic medications or diet may need to be adjusted.

  • Should only be used when there is a clear need during pregnancy as it may harm an unborn baby. If you are planning to be pregnant or think you may be pregnant, discuss the risks and benefits of use with your doctor.
  • It is unknown if this drug passes into breast milk. Before breast-feeding, consult your physician.



Taking multiple drugs may affect how medications work and/or cause unwanted side effects. List down all the medications you are taking and inform your physician and pharmacist. Do not take, discontinue, or alter any dose of medications without prior approval of your physician.

  • Products that may interact with this medication include:
    • Antacids containing aluminum and/or magnesium, other laxatives (e.g., cleansing enemas with soap suds).


  • If overdose is suspected, contact a poison control center or emergency room immediately
    • Severe stomach cramps, diarrhea.

Notes: If you are using this medication for liver disease, your doctor may direct you to follow a low-protein diet. Follow any dietary guidelines recommended by your doctor or dietician.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and as soon as you remember, take a regular dose or if the time of the next dose is near, wait for it before taking another dose and resume your usual schedule. Do not increase the dose to compensate for the missed dose.


  • Store between 2-30 degrees C
  • Do not freeze
    • If it becomes frozen, warm it to room temperature until it is pourable again
  • A normal darkening of color may occur. If too much darkening occurs and you cannot swallow it, discard the medication and get a refill
  • Do not expose to light and moisture
  • Do not store in the bathroom
  • Keep all medications away from pets and children



Available Brands

  • Biolac [ United Biotech ]
  • Duphalac [ Abbott ]
  • Lilac [ Getz Pharma ]
  • Movelax [ Amherst Lab ]
  • Rilax [ Marching Pharma ]

Also marketed as

  • Lactul [ Yung Shin ]

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