Lactulose (Enulose, Generlac) is technically a laxative medication. While it can be used for that purpose, it is fairly rare in clinical practice that you see it used for that indication. Lactulose, in my experience, is used more frequently for patients who have hepatic encephalopathy. I will share the most common lactulose clinical pearls that I’ve encountered in my practice.

Lactulose can help reduce ammonia levels by changing the acidity of the gut. Gut bacteria breakdown the drug and the byproducts create a more acidic environment which reduces the ability of NH3 to enter the bloodstream. Essentially, NH3 turns into NH4+ which reduces the permeability into the bloodstream. As a laxative, it has an osmotic effect that promotes bowel movements. Don’t forget to rule out medications that can raise ammonia levels! Here’s a case study from the past on this topic.

Lactulose Dosing in Hepatic Encephalopathy

The dosing of lactulose is critical in the management of hepatic encephalopathy. If you overkill the dosing, the patient will not like you very much as they will have significant diarrhea. Underdosing in hepatic encephalopathy can lead to unacceptable ammonia levels and ultimately, CNS symptoms like lethargy, confusion, coordination issues, etc. The accepted dosing goal with lactulose in hepatic encephalopathy is to dose the medication to 2-3 soft stools per day. This can be difficult to attain, but it is the goal.

Administration – Sweet Taste

Lactulose has a very sweet taste. While this may be tolerable initially, many patients may become tired of it if they are on chronic therapy. It is acceptable to mix it with milk, fruit juice, or water to help with this concern.

Electrolyte Monitoring

If you review the package insert of lactulose, it mentions a warning regarding monitoring electrolytes with chronic use. In my experience, patients with hepatic encephalopathy and cirrhosis are usually on a bunch of other medications (i.e. diuretics like furosemide or spironolactone) that can impact electrolytes. Usually, we are already monitoring electrolytes, so this isn’t a really significant clinical concern in most cases.

What else would you add to this list of lactulose clinical pearls?