Anti diarrheals

Fawad ALI

Objectives

To classify commonly used

antidiarrheals

To explain the mechanism of action

and common adverse effects of each

group

To manage a patient with diarrhea

accordingly

Diarrhea

Is it one liquid stool each day?

Is it several soft, semi formed stool each day?

Is it frequent, watery stools through out the day and night?

Water 60-90% (>90%) is called diarrhea

Diarrhea

Abnormal

increase in

frequency and

liquidity of stool

Causes of Diarrhea

Bacterial infections

Viral infections

Food intolerance

Parasites

Reaction to medicines

Intestinal diseases

Functional bowel disorders

After surgical procedures

unknown

Bacteria

Source: contaminated food or water

Common bacteria:

Campylobacter

Salmonella

Shigella

Escherichia coli

Viruses

Norwalk virus

Cytomegalo virus

Herpes simplex virus

Viral hepatitis

Food Intolerance

Lactose intolerance

Parasites

Gardia lamblia

Entamoeba histolytica

Cryptosporidium

Medicines

Antibiotics

Magnesium containing

Antacids

Intestinal diseases

Inflammatory bowel disease

Celiac disease

Travelers diarrhea

Most common causative organisms:

E.Coli, E.Histolytica, Gardia Lamblia, Cholera

Can be prevented by:

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Cause Symptoms

Viral (stomach

flu)

gastroenteritis

Nausea, vomiting, watery diarrhea, fever, aches.

Usually 1-3 days.

Bacterial

infection

Diarrhea, fever, chills, sometimes blood or mucus in

the stools. Vomiting less common.

Food

intolerance/lac

tose

intolerance

Bloating, gas, cramps, loose stools hours after eating

dairy products or other offending foods. No other

signs of illness or infection.

Emotional

distress

Cramping, loose stools, predictable during times of

stress.

Types

Acute (short term)diarrhea (< 4 week)

Bacterial

Viral

parasitic

Chronic diarrhea (long term)(> 4 week)

Irritable bowel syndrome

Inflammatory bowel disease

Lactose malabsorption

Chronic laxative use

Diagnosis

History

Examination

Stool culture

Electrolytes

Fasting tests

Sigmoidoscopy

Colonoscopy

Pathology

Rapid transit of stool

Osmotic diarrhea

Secretory diarrhea

Exudative diarrhea

1. Increased luminal osmolality

Non absorbable solute in intestine

Promotes retention fluid in intestine

Stimulates peristalsis

Examples: magnesium antacids, lactase

deficiency

2. Increased chloride secretion

Fluid follows sodium chloride

into the intestine

Examples: bacterial toxins,

laxative abuse

3. Increased intestinal motility

Decreased contact time for

fluid reabsorption

Example:

diabetic neuropathy

Irritable bowel syndrome

4. Exudative diarrhea

Inflammation of intestinal mucosa

Defective fluid reabsorption

Example: ulcerative colitis

Approach to patients with diarrhea

Maintenance of fluid and

electrolyte balance

Use of anti infective agents

Use of anti diarrheal agents

Maintenance of fluid and electrolyte balance

Glucose

Sodium chloride

Potassium chloride

Trisodium citrate

ORS

Anti infective agents

Rarely required

Anti diarrheal agents

Anti motility agents

Adsorbents

Fluid and electrolyte transport modifiers

Anti motility agents

Opiates

Anti muscarinic agents

(Atropine + Diphenoxylate)

Opiates

Codeine

Diphenoxylate

Loperamide

Diphenoxylate (Lomotil)

Loperamide (Imodium)

Synthetic drugs

Chemically related to narcotic meperidine

Decrease intestinal motility

Travelers diarrhea

MOA

Inhibition of acetylcholine

release through presynaptic

opioid receptor in the enteric

nervous system

Therapeutic Indications

Severe or prolonged (>2 to 3 days) diarrhea to prevent severe fluid and electrolyte loss

Relatively severe diarrhea in young children and elderly adults.

In chronic inflammatory diseases of the bowel (Ulcerative Colitis, Crohns disease)

In ileostomies or surgical excision of portions of the ileum,

HIV/AIDS associated diarrhea

When specific causes of diarrhea have been determined

Adverse effects

Constipation

Abdominal cramps

Drowsiness

Dizziness

Physical dependence

CONTRA INDICATION

Diarrhea caused by

toxic material,

microorganisms,

antibiotic associated colitis

Anti cholinergics

Decrease cramping, motility and hyper secretion

combination with opiates

Example:

Diphenoxylate + Atropine

Two half lives

21/2 h for Diphenoxylate

3 to 20 h for atropine

Onset of action: 45 to 60 min

D.O.A: 3-4 hours

Adsorbents

Adsorbents

Kaolin

Pectin

Charcoal

Methyl cellulose

Bismuth salts

MOA

Adsorb intestinal toxins

Agents reducing electrolyte secretion

α 2 agonist