Hepatic encephalopathy is a condition characterized by deterioration in brain function caused by a buildup of blood ammonia resulting from severe liver disease. Symptoms include sleepiness, irritability, agitation, apathy, confusion, inability to concentrate, impaired judgment, tremors, involuntary jerking, personality changes, moodiness, disorientation and slurred speech. Progression may result in coma and possibly death. Treatment focuses on lowering blood ammonia and preventing acute recurrence. Chronic hepatic encephalopathy requires ongoing medical management.
Lactulose
Intestinal bacteria metabolize dietary proteins, giving off ammonia. The chemical is absorbed into the bloodstream and normally detoxified by the liver. People with severe liver disease, however, are unable to effectively detoxify ammonia absorbed from the intestines and blood ammonia overload develops.
Lactulose is a man-made unabsorbable sugar that is commonly used to treat patients with hepatic encephalopathy. Intestinal bacteria metabolize lactulose into acids, which change the chemical balance in the bowel and curb ammonia production. Increased concentration of intestinal acids also inhibits the growth of bacteria that cleave proteins in ways that lead to ammonia release. Additionally, lactulose has a laxative effect. The rapid rate of stool elimination decreases the contact time between intestinal bacteria and unabsorbed dietary proteins, further lowering the rate of ammonia formation.
The American College of Gastroenterology recommends lactulose as initial medicinal therapy for patients with acute hepatic encephalopathy. The drug is typically administered orally or through a tube placed into the stomach. Hourly dosing is the norm until the bowel is evacuated. Lactulose enemas may be used in patients with significantly impaired consciousness. Long-term oral lactulose therapy remains the standard treatment for patients with chronic hepatic encephalopathy.
Antibiotics
Antibiotics may be used to reduce the number of ammonia-forming bacteria in the intestine among people with hepatic encephalopathy. Patients who cannot tolerate lactulose, or who continue to have symptoms despite lactulose treatment, are typically placed on antibiotic therapy. In the 2009 article "Current Trends in the Treatment of Hepatic Encephalopathy" published in "Therapeutics and Clinical Risk Management," Drs. Mohamad Al Sibae and Brendan McGuire report that neomycin and, less commonly, metronidazole are the antibiotics of choice for hepatic encephalopathy. In 2010, the U.S. Food and Drug Administration approved the antibiotic rifaximin as another treatment option for hepatic encephalopathy.
Dietary Adjustments
The American College of Gastroenterology states that patients with liver cirrhosis require 1.0 to 1.5 g of protein per kilogram of body weight per day. In the setting of hepatic encephalopathy, the College recommends preferentially including dairy and vegetable protein over animal protein. Supplemental zinc may be required for patients with a zinc deficiency.
References
- "Therapeutics and Clinical Risk Management"; Current Trends in the Treatment of Hepatic Encephalopathy; Mohamad Rasm Al Sibae, M.D., Brendan M. McGuire, M.D.; July 2009
- "American Journal of Gastroenterology"; Hepatic Encephalopathy; Andres T. Blei, M.D., et al.; 2001
- U.S. Food and Drug Administration: FDA Approves New Use of Xifaxan for Patients with Liver Disease
- Medline Plus: Hepatic Encephalopathy
- PubMed Health: Lactulose
