1. Diarrhea results from an imbalance of fluid and electrolyte secretion and reabsorption in the gut and can be caused by infection, motility disorders, IBS, or secretory tumors. 2. Oral rehydration therapy with a glucose-electrolyte solution is the first priority to maintain fluid and electrolyte balance, especially for mild to moderate diarrhea. 3. Drugs may also be used such as antimotility drugs like opioids, antispasmodics like anticholinergics, and anti-infectives depending on the cause of diarrhea.

1. Dr.Jannatul Ferdoush
Assistant Professor
Department Of Pharmacology
*

2. •
• Diarrhoea is a frequent passage of liquid feces
resulting from an imbalance between secretion
& reabsorption of fluid & eletrolites.
• Causes:
1 .Infective
2.gut motility disorder.
3.IBS & malabsorption due to disease.
4.secretory tumour of GIT-
carcinoid tumour & vipoma.

3. •
• 1.For mild to moderate diarrhoea
Maintenance of fluid and electrolyte balance .
• 2.For severe acute diarrhoea
Maintenance of fluid and electrolyte balance.
Antimotility & antispasmotic drug.
antiinfective agents.

4. •
*Oral rehydration therapy with glucose-electrolite solution to
maintain the fluid & electrolite balance is the first priority.
*Composition of Oral rehydration salt:
*Na 75mmol/l
*Cl 69mmol/l
*Glucose 75mmol/l
*K 20mmol/l
*Citrate 10mmol/l
*Advantages:
Simple,effective,cheap,readily administered therapy for a
potentially fatal condition.
Hypotonic solution, so can cause more Na and water retension.

5. •
• Antimotility drug—
opioid agonist
• Antispasmotic drug—
M-R antagonist
Direct acting muscle relaxant
• Antiinfective agent—
Erythromycin,ciprofloxacin.
• Adsorbent—
kaolin,pectin,charcoal,methylcellulose.
• Octreotides

6. •
*Opioid agonist—
loperamide
Diphenoxylate
codeine
Role in GIT motility—
tone & rythmic contraction of the intestine.
propulsive activity.
tone of the large intestine.
secretion of intestine.
All sphincter are contracted.

7. *
• Advantages:
Cannot cross the blood brain barrier, so use only
for their action on GIT.
• Disadvantages:
Constipation,abdominal cramp,drowsiness,dizziness.
Large dose Diphenoxylate produces typical opoid effect.
So small dose of Atropine is used in combination to
discourage overdose.
• Contraindication:
Acute diarrhoea in children—cross BBB—respiratory
depression.
IBS—toxic dilatation of the colon.

8. *
*M-R antagonist—
Atropine
hyoscine
propantheline
dicycloverine
Role in GIT:
Inhibit M-R in the enteric nerve plexus & on smooth
muscle.
Inhibit parasympathetic activity.
Decreases spasm of intestine.

9. *
*Direct acting muscle relaxant:
Mebeverine—derivatives of reserpine.
Role in GIT:
direct relaxation action on smooth muscle of intestine.

10. *
* Diarrhoea
• Mostly viral in origin—
No antibiotic required.
Only fluid & electrolite replacement.
• Bacterial origin---mostly campylobacter species
Rx– erythromycin or ciprofloxacin.
• Travellers diarrhoea:
E.coli common.
Rx—no antibiotic required.
Only fluid & electrolite replacement

11. *
• Octreotides :synthetic analogue of somatostatin.
• Role in GIT:
It enhances Intestinal fluid secretion.
slows GIT motility in high doses.
• Use:
after vagotomy.
AIDS .
•Disadvantages:
steatorrhoea leads to deficiency of fat soluble vitamins.
Alteration of GIT motility causes nausea,
abdominal pain,flatulence.

12. •