Lactulose is a synthetic disaccaride compound of two
monosacchrides:
Galactose and Fructose joined by an oxygen
bond (unlike lactose which is resemble in structure)
lactulose has no corresponding disaccharidase enzyme
in human intesttinal mucosal cells thus ingested lactulose
is not split into its component monosaccharides and
travels intact to the colon.
Therapeutic Category:
Ammonium detoxicant.
Laxative.
Mechanism of Action:
Lactulose is broken down in the colon by (bacterial
floral) i.e Lactobacilus, Bacteroids ,
Escherichia coli and Streptococcus faecalis
resulting in the formation of formic, lactic and acetic
acid and carbon dioxide.
These products will increase the osmotic pressure of
the colon and so,
increase water contents of the stool and softening it.
Also, the acidic media will change the ammonium ions
into the ammonia which
will trapped in the colon and not transferred to the
blood.
Indications:
Laxolac is suited for the treatment of the constipation,
the volume and frequency of deification is increased
in the relation to the administrated dose.
laxolac is suited also the treatment of portal-systemic
encephalopathy, in high dose laxolac can be
used orally or rectally as enema to accelerate intestinal
transit and increase the acidity of the colon which
subsequently reduce the absorption of ammonia from
the colon to the blood.
n.b; Sorbitol is a non absorbable sugar alcohol
which has the similar effect but not as thoroughly
documented.
Pharmacokinetics:
Bioavilability:
Minimal absorption of lactulose occurs.
Onset of action:
24-48 hr.
Elimination:
very small amount in the urine and stool.
Adverse Reaction:
Gaseous distention with flatulence, also nausea and
vomiting may occur.
