Pharmacology diarrhea

1. DIARRHEA

2. Contents:
• Def
• Causes
• Types of diarrhea
• Treatment
• Classification of anti diarrheal drugs

3. DIARRHEA:
• Diarrhea is defined by the World Health Organization
(WHO) as three or more watery or loose bowel
movements in a 24 hour period.
OR
• Diarrhea is the too rapid evacuation of too fluid stool
OR
• frequent liquid stool d/t an intestinal disorder
• can be mild to severe - ID underlying causes first
• can cause minor or severe dehydration & electrolyte
imbalance
• can be life threatening to the young & elderly

4. • DIARRHEA: Diarrhea is defined by the World Health
Organization (WHO) as three or more watery or loose
stools or bowel movements in a 24 hour period. Diarrhea is
the too rapid evacuation of too fluid stool Increase in the
stool weight to greater then 250g per day accompanied by
increased frequency and liquidity of stool is called diarrhea.
• Causes : bacterial & Viral infection.
Excessive consumption of alcohol.
Over eating & Incomplete digestion of food.
Intestinal disorder or disease.
Poor eating habits & Unpurified water
Water consumption is not sufficient.

6. CLASSIFICATION OF DIARRHEA:

7. • Classification of diarrhea:
On basis of duration
• Acute diarrhea.
• Chronic diarrhea
• Acute diarrhea: Diarrhea lasting less than 2 weeks is
considered acute This phenomenon is most likely
caused by an infectious agent, such as bacterial,
parasitic or viral invasion, or by a non-infectious agent
such as dietary indiscretion or a new medication. It
may result from emotional stress, food intolerance,
organic substances , drugs.

8. • Acute infectious diarrhea is divided into two groups as following:
1) Inflammatory or bloody diarrhea: Inflammatory diarrhea suggests
involvement of large intestine by invasive bacteria or parasites or
toxins. pathogens can cause an inflammatory response in the gut
where the epithelial lining is damaged either by a toxin produced by
the organism or by an organism invading the mucosa. Some organisms
that cause an inflammatory response are “Cytomegalovirus, Herpes
simplex virus, Shigella, Salmonella, Chlamydia ,Clostridium difficile,
Escherichia coli, Entamboeba histolytic”
• Sign & symptoms: Clinically patient presents with frequent bloody,
small-volume stools, often associated with fever, abdominal
cramps. acute inflammatory diarrhea include lethargy, and a stool
that contains pus, blood, leukocytes and/or mucus .

9. acute inflammatory diarrhea include lethargy, and a stool
that contains pus, blood, leukocytes and/or mucus .
• Pathogenesis (Inflammatory (invasive) diarrhea)
In this group of infections, the infectious agent invades
the intestinal mucosa causing acute inflammation of the
intestine. Following organisms produce invasive intestinal
infections.
• Viruses: Adenovirus, cytomegalovirus
• Bacteria: Salmonella, shigella, campylobacter.
• Parasites: Entameba histolytica.

10. • Non-Inflammatory diarrhea: Non-inflammatory diarrhea is gradually
a milder disease and is caused by viruses, or toxins. There are organisms
that cause acute diarrhea that do not produce an inflammatory response.
These causative organisms include Rotovirus, Staphylococcus aureus,
Vibrio cholerae and Escherichia coli” Less commonly, protozoa such
Giardia or Cryptosporidium may be the causative agent.
• Sign & symptoms: interfere salt and water balance, resulting in large-
volume watery diarrhea, often with nausea, vomiting and cramps. low
grade fever, malaise.
• PATHOGENESIS (Non-Inflammatory diarrhea): In this group organism
does not invade the intestinal mucosa and its effects are mediated by its
enterotoxin (exotoxin). These is no inflammation of intestinal mucosa.
Following organisms produce exotoxin-mediated diarrhea
– Vibrio cholera
– E. coli-toxigenic
– Staphylococcus aureus
• The organism exist in the intestinal lumen and does not invade the tissue.
Organism is Giardia.

11. • Food poisoning: The disease caused by toxins
present is consumed foods is called food
poisoning.

12. • Chronic diarrhea: Diarrhea lasting longer than two weeks but
resolving within a month is called chronic diarrhea. Chronic
diarrhea can be the result of disease processes, medication, genetic
abnormalities, or a variety of other causes
• Approximately 10 liters of fluid can move through the small
intestine in a 24 hour period from food, fluids, and secretion of
various enzymes and fluids necessary for digestion.
• Classification of diarrhea :
On basis of Pathological disorder
• Secretory Diarrhea.
• Osmotic Diarrhea.
• Motility disorders.
• Mixed disorders.
• Diarrhea due to chronic infection
• Inflammatory Diarrhea

13. • Diarrhea due to chronic infection: Causes are
Giardia lamblia, Entameba, histolytica, and
abdominal tuberculosis.
• Travelers diarrhea: Whenever a person travels
from one country to another—particularly if
the change involves a marked difference in
climate, social conditions, or sanitation
standards and facilities—diarrhea is likely to
develop within 2–10 days

14. INVESTIGATIONS
• Stool analysis: Stool examination is perfumed to detect.
• Stool culture in bloody diarrhea
• Serum electrolytes
• Serum urea and creatinine
• Stool osmolality: An osmotic gap confirms osmotic diarrhea.
• Proctosigmoidoscopy: It may be require if inflammatory bowel
disease is suspected.
• Upper GI endoscopy with small bowel biopsy: It is performed if
malabsorption is suspected.
• Blood tests: Deficiency of particular nutrient help in identification
of sight of its absorption and other factors that are required for
digestion and absorption.
• Blood CP—anemia occurs due to iron, B12 or folic acid deficiency.
• Electrolytes—hypernatremia in secretory diarrhea.

15. MANAGEMENT
• Goals of treatment:
• Control the loss of fluids
• Identify and treat cause
• Provide symptomatic relief (antidiarrheal
drugs )
• Refer to physician if: Persists for several days
• Blood in stool & severe abdominal pain,
cramps

16. Treatment and management:
• Correction of underlying causes:
• thorough history and physical examination
• Dietary measures
• Adding fiber,
• limiting the amount of caffeine consumed, decreasing
or eliminating spices that make foods hot.
• A common diet for people with acute diarrhea to
follow is the BRAT diet which consists of Bananas, Rice,
Apple and Toast
• Soft easily digested diet such as soup is preferred
• Frequent feedings of fruit drinks, tea are encouraged.

18. • Rehydration
• Oral rehydration solution (ORS)
• It is inexpensive, safe and highly effective in almost all awake patients.
Fluid should be given at the rate of 50-200 ml/kg/d depending on the
dehydration state.
• Intravenous fluid
• Intravenous fluids are preferred in patients with severe dehydration.
Normal saline or Ringolactate is given to restore water and electrolytes.
• Anti-diarrhea agents:
• Increased motility of the gastrointestinal tract and decreased absorption
of fluid are major factors in diarrhea. Antidiarrheal drugs used to treat
acute diarrhea include antimotility agents, adsorbents, and drugs that
modify fluid and electrolyte transport.
• Antimotility agents
• Two drugs that are widely used to control diarrhea are diphenoxylate and
loperamide .At the usual doses, they lack analgesic effects. Side effects
include drowsiness, abdominal cramps, and dizziness. Anti-diarrheal drugs
such as loperamide (Imodium 2mg) 4mg initially then 2 mg after each
loose stool (max 16mg/d).

19. • Adsorbents
• Adsorbent agents, such as aluminum hydroxide and methylcellulose are used to
control diarrhea.
• these agents act by adsorbing intestinal toxins or microorganisms and/or by
coating or protecting the intestinal mucosa. They are much less effective than
antimotility agents and they can interfere with the absorption of other drugs.
Kaolin often combined with Pectin. This product adsorbs bacterial toxins, binds
water and decreases mucus secretion
• Agents that modify fluid and electrolyte transport
• Bismuth subsalicylate, used for traveler’s diarrhea, decreases fluid secretion in the
bowel. Its action may be due to its salicylate component as well as its coating
action. Adverse effects may include black tongue and black stools.
•
• Bile Acid Sequestrant: Bile acid diarrhea can occur when a person has had the gall
bladder removed or when there is a problem with the terminal ileum, either
through an inflammatory bowel disease or when the ileum has been resected.
Cholestyramine is a drug that binds with bile acid in the bowel, effectively
neutralizing the acid. Adverse reactions include …constipation, heartburn, nausea
and vomiting, diarrhea, flatulence, rash and fat soluble vitamin deficiency.
Cholestyramine has the potential to decrease the availability of certain drugs,
including but not limited to warfarin, thiazide diuretics, propranolol, tetracycline,
penicillin G, phenobarbital, thyroid medications, estrogens, progestins and
digitalis. Therefore, cholestyramine should be taken either one hour before or four
hours after other medications .

20. • Heavy Metals: Heavy metals, such as bismuth, have been found to
decrease liquid stools. Bismuth has anti-inflammatory, anti-infective
and anti-secretory properties and works well for traveler’s diarrhea,
an infectious diarrhea usually caused by enterotoxigenic E coli.
Bismuth subsalicylate is not to be used for children younger than 12
years of age and should not be used for children or teens with
chicken pox or flu symptoms. Cautions against the use of bismuth
subsalicylate in conjunction with aspirin or aspirin containing
products. This drug should be discontinued if signs and/or
symptoms of aspirin toxicity occur. Bismuth subsalicylate has the
potential to interact with anticoagulants, anti-diabetic, anti-arthritic
and anti-gout medications .The patient should be cautioned that
bismuth subsalicylate may cause stools to turn black and this may
continue for several days after the medication has been stopped
• Antibiotic therapy.Antibiotics are indicated for infectious diarrhea
but should be used with caution due to the increasing problem with
resistant bacteria propose the use of selected antibiotics only .The
drug of choice is quinolone such as ciprofloxacin (Ciproxin) 500mg
twice daily for 5-7 days. Empirical therapy with metronidazole
(Flagyl) 250-500mg four times daily .