Therapy of Diarrhoea

• Absorption of ions:
• Cl-, HCO3- absorption is passive 
• HCO3- is also exchanged for Cl-
• Bicarbonate (accompanied by Na+) absorbed secretion of H+.
• K+ excreted by exchanging with Na+, also excreted by secretion to mucus.
• 
  
• Secretary process stimulated by PGs and intracellular Ca2+
• All acute enteric infections produce secretary diarrhoea. 
• Accumulation of cGMP caused by the heat stable toxin of Clostridium difficale and E. Histolytica
• enhances anion secretion.
• Carcinoid diarrhoea mediated by cAMP
• Bile acids case diarrhoea by activating adenylyl cyclase. 
• Hyper motility of bowel now considered to be ofsecondary role in diarrhoea.

Rational Of ORS

For more than 25 years, WHO and UNICEF recommended a single formulation of glucose-based

Oral Rehydration Salts (ORS) to prevent or treat dehydration from diarrhoea irrespective of the cause or age group affected.

Standard formula recommended was:

Nacl      60 mM (3.5 gm)

KCl      20 mM (1.5 gm)

Trisodium citrate    30 mM (2.9 gm)

Glucose     110mM (20 gm)

to be dissolved in   1 litre of water

Drug therapy

Antimicrobials:

Antimicrobials have limited role in overall treatment of diarrhoeal patients. 

Antimicrobials are of no value in diarrhoea due to non infective cases such as:

1.IBS

2. Coeliac disease 

3. Pancreatic enzyme deficiency

4. Topical sprue

5. Thyrotoxicosis. 

Antimicrobials regularly useful in:

1. Cholera: 

Tetracyclines (Doxycycline), Cotrimoxazole,

erythromycin.

2. Campylobacter jejuni

Norfloxacin, fluorquinolones. Erythromycin

3. Clostridium difficale associated pseudomembranous colitis: 

Metronidazole.

4. Amoebiasis and giardiasis

Anticholinergic agents:

Can reduce bowel motility and secretion, have poor

effect in secretary diarrhoeas.

Octreotide:

Somatostatin analogue, potent antisecretory and antimotility action on gut. 

These are opioid drugs which:

• Reduce propulsive movements
• Diminish intestinal secretions
• Enhances absorption 

MOA: Mediated via µ receptors (enteric neuronal network)

Codeine:

Anti-diarrhoeal effect attributed to its action on small

intestine and colon.