Lactulose
Class:laxatives
Mechanism of action
The bacterial
degradation of lactulose resulting in an acidic PH inhibits the diffusion of NH3
to NH4+;also enhances the diffusion of NH3 from the blood
into the gut where conversion to NH4+ occurs;produces an osmotic
effect in the colon with resultant distention promoting peristalsis.
Pharmacokinetics
Absorption:oral:not
absorbed appreciably following administration;this is desirable since the
intended site of actin is within the colon.Metabolism:by colonic flora to
lactic acid and acetic acid,requires colonic flora for primary drug
activation.Elimination:primarily in feces and urine.
Indications
Lactulose is
indicated for the treatment of constipation,portal systemic encephalopathy(PSE)
Contraindications
Galactosemia and
require a low galactose diet.
Precautions
Lactulose contain
lactose(less than 0.9 g/15 ml).this should be taken into account when treating
patients with lactose intolerance.
Side effects
During the first few
days of treatment meteorism and increased flatulence may occur.these symptoms
usually disappear under continued therapy of lactulose.
Pregnancy and
lactation
Pregnancy risk factor
B.Lactulose does not appear in the breast milk of lactating mother,and so the
baby will not suffer from diarrhea.
Drug interaction
Decreased effect:Oral
neomycin,laxatives,antacids
Dosage
Constipation/maintenance:Dose
is taken preferably with breakfast.Adults:15-45 ml per day.Children:5-15 ml per
day.Portal systemic encephalopathy(PSE):Starting dose:30-50 ml three times a
day.
Brands
Syp.Duphalac,Syp.Lilac
