What is lactulose?
Lactulose (brand names Cephulac®, Kristalose®, Generlac®, Constulose®, Enulose®) is a disaccharide (sugar) laxative and ammonia reducer. It is used off label (extra label) in cats, dogs, birds, and reptiles to reduce blood ammonia levels during liver dysfunction, to soften the stool, and to treat constipation.
Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.
How is lactulose given?
- Lactulose is given by mouth, in the form of a liquid syrup or crystal granules.
- It may be mixed with food, but ensure your pet swallows the entire dose.
- Measure the liquid form carefully.
- Cats generally do not like the taste of this medication; contact your veterinarian if you have trouble administering it.
- Make sure your pet always has access to plenty of clean drinking water while using this medication.
This medication should take effect within 1 to 2 days, and improvements in clinical signs should follow.
What if I miss giving my pet the medication?
If you miss a dose, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.
Are there any potential side effects?
Lactulose may cause the following side effects, which usually resolve over time:
- diarrhea
- bloating
- gas
- abdominal cramps
At higher doses, side effects may include:
- low blood potassium levels and/or
- high sodium blood levels.
This short-acting medication should stop working within 24 hours.
Are there any risk factors for this medication?
Lactulose should NOT BE USED in pets that:
- are allergic to it
- have an intestinal blockage/obstruction
Lactulose should be USED WITH CAUTION in pets that:
- have diabetes
- have fluid/electrolyte imbalances
- are pregnant or lactating
Are there any drug interactions I should be aware of?
The following medications should be used with caution when given with lactulose:
- antacids
- gentamicin
- laxatives
- neomycin
- warfarin
It is important to tell your veterinarian about any medications (including vitamins, supplements or herbal therapies) that your pet is taking before starting any treatment.
Is any monitoring needed with this medication?
- Your veterinarian may monitor blood electrolytes if lactulose is used long term.
- In diabetic patients, blood glucose levels should be monitored.
- Your veterinarian may monitor your pet to be sure that the medication is working.
How do I store lactulose?
- Store at room temperature between 20°C and 25°C (68°F and 77°F), in a tight container.
- Protect from heat and light.
- Do not freeze.
What should I do in case of emergency?
If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.
