Lactulose is a non-absorbable disaccharide that works by drawing water into the colon, which softens the stool and increases its bulk. This osmotic effect stimulates bowel movements. Additionally, lactulose is fermented by colonic bacteria into short-chain fatty acids. These acids lower the colon's pH, which inhibits the absorption of ammonia from the gut into the bloodstream. By reducing ammonia levels, lactulose is used to treat hepatic encephalopathy [1].
How does lactulose help with constipation?
Lactulose's primary mechanism for relieving constipation is its osmotic action. It acts as a laxative by retaining water in the intestinal lumen. This increases intra-luminal pressure and stimulates peristalsis, the wave-like muscle contractions that move food and waste through the digestive tract. The resulting softer, more frequent stools are easier to pass [1].
How does lactulose affect ammonia levels?
In the context of hepatic encephalopathy, lactulose's effect on ammonia is crucial. Colonic bacteria metabolize lactulose into acidic compounds, which lower the pH of the colon. This acidic environment converts ammonia (NH3) to ammonium (NH4+). Ammonium is less readily absorbed from the gut into the portal circulation compared to ammonia. By trapping ammonia as ammonium in the colon, lactulose facilitates its excretion from the body, thereby reducing the ammonia load on the liver and brain [1].
What is lactulose used for besides constipation?
Beyond its use for constipation, lactulose is primarily prescribed for the management of hepatic encephalopathy, a complication of liver disease where toxins, including ammonia, accumulate in the brain. It is also sometimes used to treat chronic constipation in patients with specific medical conditions or to prepare the bowel for medical procedures [1].
Are there different types of lactulose?
Lactulose is available as an oral solution or syrup. It is not typically formulated in other dosage forms due to its intended mechanism of action within the gastrointestinal tract.
When does the patent expire for lactulose?
Lactulose is a well-established medication, and its original patents have long since expired. This means that generic versions of lactulose are widely available, contributing to its affordability and accessibility [2]. For specific patent information on newer formulations or combination products that might involve lactulose, resources like DrugPatentWatch.com can be consulted [3].