is non absorbable disaccharide (galactose- fructose) non absorbed in the small intestine.
metabolized by colonic intestinal bacteria into low molecular weight acids (acetic acid, lactic acid and formic acid) which:
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decreases PH of colonic environment to inhibit ammonia producing bacteria and favor ammonia transport from blood to colonic lumen where it is converted to ammonium ion which is poorly absorbed but excreted in the stool due to its osmotic laxative effect.
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osmotic laxative by acceleration colonic transit time and increase excretion of ammonia ion.
uses:
Less used in acute attack due to slow onset of action (1-2 days) but used in : *prevention of portosystemic encephalopathy.
- patient with advanced hepatic cirrhosis to improve patient tolerance.
- laxative.
- may be used orally or in the form of retention enema (In patient with impending coma or in patient with coma stage of hepatic encephalopathy)
side effects:
At therapeutic doses: abdominal distension, flatulence, nausea, vomiting, diarrhea all these side effects can be controlled with decreasing doses so, this drug can be used for a long time with less side effects.