3. DEFINATION:
LAXATIVES are the drug which promote the
evacuation of bowels.
• Mild laxative action are called as LAXATIVE/APERIENTS.
• Strong laxative are called as CATHARTICS/PURGATIVE
6. Bulk laxative:
Mechanisms of action
• This are the complex polysaccharides which
increases the bulk by forming bulky hydrated mass
in the lumen of intestine creating pressure and
promoting peristaltic followed by defecation.
• It take days to produce action.
• Ex: (1) Bran :It is by-product of the milling of wheat .
-The it constitute of 40% of dietary fibre
-the mechanisms of action of barn is that it absorb water in intestine
swells and increases its mass.
Adverse effect: (1) It is unpalatable.
(2)Flatulence may occur.
(3) Patients with ulceration are contraindicated.
7. .(2) Isabgol : In this isabgol husk is used as laxative.
• It form gelatinous mass by absorbing water.
• Adverse effect: it cannot be swallow easily.
• It show action within 1-3 days.
(3)Methyl cellulose: dose:4-6g per day.
8. Stool softeners
• This is surfactant come anionic detergent.
Ex:(1) DOCUSATE SODIUM(DOSS): mechanisms of
action :it emulsifies prolong its content and
increases the penetration of water in faeces .
Drug interaction : It should not be given with liquid
paraffin as it cause synergistic effect which cause
diarrhoea like effect.
– Adverse effect: cramps(painful involuntary
contraction of a muscle or muscles, typically caused
by fatigue or strain.) and abdominal pain occur.
-Bitter and liquid preparation cause nausea.
-hepatotoxicity may occur on prolong use.
9. • (2) liquid paraffin: It was introduced in 19
century.
• It is less widely used.
• MOA: It soften the stool by lubricating and
coating them.
• Adverse effect: small amount pass into
intestine…(in general if we take 100mg then only
10mg will show effect in intestine.)
• It carry away fat soluble vitamin with it.
Docusate
10. STIMULANTLAXATIVE
This drug stimulate intestinal mucosa which promote
peristalsis and cause defecation.
• It take few minute to produce it action.
• EX: (1) Bisacodyl: It is often given as suppository
which cause defecation within 15 to 30 minute.
• (2) phenolphthalein: It is an indicator but also act
as stimulant laxative .
• Adverse effect: It causes pink urination.
-on large doses it causes “ STEVEN JOHNSON’S
SYNDROME” is reported.(A rare, serious disorder
of the skin and mucous membranes.)
11.
12. • (3)Senna and Dendron : it is naturally occurring
glycosides which directly stimulate intestinal
mucosa and causes laxative action.
• (4)Castor oil : it is a fixed oil obtained from the
seeds of Ricinus communis.
• It is hydrolysed in the small intestine to ricinoleic
acid which acts as local irritant that increases
intestinal motility .
14. OSMOTIC LAXATIVE
• This drug show osmotic difference between
intestine and blood & results in softening of
intestine content which promotes peristalsis &
followed by dedication.
• Ex:(1) MgSO4(epsom salt) :-dose=5-15g and it is
bitter in taste.
• (2) Mg(oH)2(milk of magnesia) :-30ml of 8% w/with
suspension.
• (3) Na2SO4 (glauber salt) :- dose:-10-15g and it is
bad in taste.
15. • (4)DISODIUM PHOSPHATE ( Na2Po4):- dose=6-12g
• (5) Sodium potassium tartrate (rochelle salt) :-
dose=8-15g
• Pleasant in taste.
• (6) lactulose :- it is semi synthetic disaccharides of
fructose and galactose .
• It take 2-3 days to act.
• Adverse effect:- flatulence, cramps, diarrhoea ,
electrolyte disturbance.
• On high dose hepatotoxicity occur.
• Tolerance is develop.
• (6)Macrogols (PEGS):- it consists of inert ethylene
glycol polymers, which act in same ways.
