Poisoning caused by an excess of ammonia. Ammonia is produced in the intestinal tract by bacterial action. After absorption it is transported to the liver, where it is converted to the less toxic urea. In diseases such as cirrhosis of the liver, the ammonia absorbed may be shunted past the liver. This results in an accumulation of ammonia in the blood (ammoniemia). Alterations in consciousness (such as impaired concentration, distractibility, and amnesia) and a flapping tremor (asterixis) may be partly due to the toxic effects of ammonia on the brain or may be caused by metabolic changes that accompany high serum ammonia levels. Synonym: ammonia intoxicationportal-systemic encephalopathy
Treatment is aimed at preventing production and absorption of ammonia in the intestinal tract. Laxatives (such as lactulose) and antibiotics (such as neomycin) are used to reduce the production and absorption of ammonia from the intestines. Dietary protein should be limited.