This document summarizes different types of drugs used to treat constipation. It describes bulk forming agents, osmotic agents, stool softeners, and stimulant purgatives. It provides details on specific osmotic laxatives like magnesium sulfate and lactulose, explaining their mechanisms of action, indications, dosages, and side effects. The document warns that long-term use of stimulant laxatives can lead to a condition called cathartic colon.

1. Drug used in constipation
Dr.Jannatul Ferdoush
Assistant Professor
Department Of Pharmacology

2. • Constipation :
Absence of propagating contraction in colon.
• Purgatives:
They are medicine that promote defecation
largely by reducing the viscosity of the content
of the lower colon.

3. Classification of purgatives
• Luminally active agent:
1.Bulk forming agent- Several days( at least 3 day)
bran
ispagula husk
methylcellulose
2.Osmotic agent- inorganic salt- (with in 3 hours)
magnesium hydroxide
Magnesium sulfate.7H2O
Lactulose

4. Stool (fecal) softeners( emollients)(reliefs within 1-2 days)
Docusate sodium
Liquid paraffin
Stimulant purgatives:
Bisocodyl ( 6-10 hrs)
glycerol
sinna(8-12 hrs)
Danthron(6-12hr)
Prokinetic agent
5HT4 agonist
opioid antagonist
Enema & suppositories( 1 hrs)

5. M/A of Bulk & osmotic laxatives
Retain water in the intestinal lumen
↓
↑Bulk of the stool& gives pressure on the lumen
↓
Stimulate enteric nerve plexus
↓
↑Peristalsis
↓
Evacuation of stool

6. • Indication:
Hemorrhoids
Anal fissure
Diverticular disease
Irritable bowel syndrome
A/E:
Cathertic colon
Malabsorption syndrome
Proteinloosing enteropathy
Paralytic ileus

7. Osmotic laxatives
• Where a rapid bowel evacuation is required,
magnesium sulphate is still used.
• This should be used in a dose before breakfast or on
an empty stomach, followed by plenty of warm
fluid.
• This treatment usually causes evacuation within 2
hours

8. Magnesium sulphate (MgSO4) Epsom salt
• MgSO4 dissociate into Mg & SO4. This Mg draws
water from intestine causing softer stool & help in
evacuation
• MgSO4 is usually given in empty stomach
It may cause uremia in patients with renal
insufficiency

9. Lactulose
• It is a semi synthetic disaccharide of fructose &
galactose.
• Taken orally, it is unaffected by small intestinal
disaccharidase, is not absorbed
• In the colon, bacteria convert it to its two
component sugars, which are poorly absorbed;
when these are fermented, the lactic acid & acetic
acid are formed which function as osmotic
laxatives. It takes 2-3 days to act

10. • Indication:
–constipation,
–hepatic encephalopathy
• Contraindications:
–galacosaemia,
–intestinal obstruction

11. • Side effects: flatulence, cramps, & abdominal
discomfort
• Dose: expressed in terms of an eoral solution
containing lactulose 3.35 g/5ml
• Constipation, adults initially 15 ml twice daily,
gradually reduced according to patients needs; child
under 1 year 2.5 ml, 1-5 years 5 ml., 6-12 years 10
ml twice daily, gradually reduced
• Hepatic encephalopathy, 30-50 ml 3 times daily,
subsequently adjusted to produce 2-3 soft stools
daily
• Avolac (solution, 3.35 mg/5ml), D-Lac (syrup),
Laclose (syrup), Osmolax (syrup)

12. Magnesium hydroxide
• Indication: mild constipation (acts in 2-4 hours)
• Caution: use only occasionally; the elderly; renal
impairment; hepatic impairment
• Contraindication: intestinal obstruction
• Dose: Aqueous suspension containing about 8%
hydrated magnesium oxide, 25-50ml as & when
required
• Magna milk, milk of magnesia (susp 400 mg/5ml)

13. Fecal softner
• Decusate:
Softening the stool by↓ surface tension of
stool which allows more water to remain in
the feces.
It has bowel stimulant property.
↑ Intestinal fluid secretion, It mix with stool
& stool become soft.

14. Liquid paraffin
• Chemically inert mineral oil
• Not digested
• Tasteless
• M/A:
• Lubricates the intestinal wall
• Easy & increase rate of passage of gut contents
• Reduce absorption of water in the small intestine
• Retain more water in the gut contents
• Softening of the stool
• Easy evacuation

15. • Side effects :
Anal leakage following large doses of paraffin cause
physical & social discomfort.
Granulomatous reactions caused by absorption of
small quantities of liquid paraffin (especially from
the emulsion)
Lipoid pneumonia (taken orally for long period,
especially at night, may be aspirated & cause
chronic lipoid pneumonia)

16. Stimulant purgatives
• Most strong laxatives
• Induces low grade inflammation in small &
large intestine to promote accumulation of
water & electrolyte
• Stimulate gut motility.

17. • Dependence:
- Stimulant empty the whole colon. But normal
defecation only empties the descending colon .
-Cessation of use after a few weeks is followed by a
few days constipation to collect significant
materials to restore the normal state.
-This delay may convince the patient to continued
need for purgatives.

18. • Enema:
containing 130 ml of arachis oil (ground-nut
oil) would lubricate & soften impacted faeces
& promote bowel movement.
• For children above 6 years, the dose has to be
reduced in proportion to body-weight; not
recommended for children under 6 years

19. Cathartic colon
• It is the anatomical and physiological changes
in the colon that occurs with chronic use of
stimulant laxatives.(> 3times/weeks) for 1 yr
• S/S—
Bloating
Feeling of fullness
Abdominal pain
Incomplete fecal evacuation

20. • Typically female patient.
• Long standing H/O laxative use
• Cause damage to the colonic Nerve.
• Rx – surgery.