Diarrhea And Constipation

Question 1

Drugs altering motility

Answer 1

Anti-spasmodics - decrease smooth muscle tone
Laxatives - accelerate passage
Anti-diarrhoeal drugs - decrease motiity
Pro-kinetics - increase motility of smooth muscle

Question 2

Dicyclomine

Answer 2

Antimuscarinic

Question 3

Hyoscine butyl-bromide

Answer 3

Anti-muscarinic

Question 4

Mebeverine

Answer 4

Anti-muscarinic

Question 5

Propantheline

Answer 5

Anti-muscarinic

Question 6

Falvoxate

Answer 6

Antimuscarinic

Question 7

Clidinium bromide

Answer 7

Anti-muscarinic

Question 8

Anti-muscarinics indications

Answer 8

Used as anti-spasmodics

• intestinal
• biliary
• genitourinary

Question 9

Diarrhea mechanisms

Answer 9

1. Increased osmotic load - water retention in lumen
2. Excessive secretion of electrolytes
3. Exudation of protein and fluid from mucosa
4. Altered motility - rapid transit and decreased fluid absorption (inflammatory/infectious)

Question 10

Diarrhea Mx

Answer 10

1. Prevent dehydration
2. Anti-infective - curative
3. Spasmolytic or other antidiarrhoeal (symptomatic)

Question 11

Loperamide

Answer 11

Anti-motility agent

Question 12

Diphenoxylate

Answer 12

Antimotility agent

Question 13

Codeine

Answer 13

Anti-motility agent

Question 14

Anti-motility agents

Answer 14

-opioid derivatives - inhibits Ach release - decreased peristalsis and increased sphincter tone

Question 15

Anti-motility agent indications

Answer 15

Traveller’s diarrhea

Adjunct in chronic diarrheal disease

Question 16

Anti motility agent SE

Answer 16

• minimal
• some BBB crossing
• low incidence of addiction

Avoid in suspected inflammatory diarrhea

• prolonged fever with shigella
• toxic megacolon in pts w. C. difficile (>6cm dilation of transverse colon)

Question 17

Bismuth subsalicylate

Answer 17

• decreases fluid secretion

- travellers diarrhoea, episodic diarrhea, acute gastroenteritis, H. Pylori eradication

Question 18

Adsorbents

Answer 18

• adsorbs intestinal toxins and microorganisms
• coats intestinal mucosa
• interferes with abrorbtion of other drugs

Question 19

Cholestiramine

Answer 19

Adsorbent - Bile acid sequestrant

Question 20

Kaolin and Pectin

Answer 20

Adsorbent

Question 21

Methylcellulose

Answer 21

Adsorbent (fermented fibre)

Question 22

Aluminium hydroxide

Answer 22

Adsorbent

Question 23

Probiotics indications

Answer 23

• acute diarrhea
• antibiotic associated diarrhea
• infectious diarrhea

Question 24

Dietary fibre

Answer 24

Laxative - bulk forming
Unfermented fibre attracts H2O and increases stool bulk - distends intestine increasing peristalsis
(fermented fibre attracts stool water - used in diarrhea)

• hydrophilic colloids
• indigestible parts of fruit and veg
• psyllium seeds, bran, ispaghula

Question 25

Osmotic active agents

Answer 25

Saline laxatives: magnesium citrate - non-absorbable salts Electrolyte solution laxatives -polyehtylene glycol Nondigestible sugars & alcohols - lactulose - semi-synthetic sugar cannot be hydrolized by intestinal enzymes - increases osmotic pressure, increase fluid, increase lumen pressure, stimulate evacuation

Question 26

Docusate sodium/calcium/potassium

Answer 26

Laxative - stool wetting agent - lowers surface tension of stools - allow mixing - may take days

Question 27

Mineral oil

Answer 27

Indigestible | -causes anal leakage and lipid pneumonitis NB

Question 28

Senna

Answer 28

Stimulant laxative | -induce limited low grade inflammation

Question 29

Bisacodyl

Answer 29

Stimulant laxative | -induce limited low grade inflammation

Question 30

Castor oil

Answer 30

- irritant laxative | - stimulates uterine contractions in pregnant

Question 31

Pro-kinetic agents

Answer 31

- increase intensity of contractions in small intestine without rhythm disruption - good in diabetics with gastroparesis

Question 32

Dopamine receptor antagonists

Answer 32

Suppress Ach release -inhibits motility, reduces LOS tone, reduce intragastric pressure - metoclopramide - domperidone

Question 33

Cisapride

Answer 33

5HT4 agonist - prokinetic agent | -ventricular arrhythmia

Question 34

Macrolide

Answer 34

Pro-kinetic agent Only used in diabetics with gastroparesis