Antidiarrheals and laxatives - Ch 84 and 83

Question 1

What drugs alter the motility of the GI tract?

Answer 1

Antidiarrheal drugs
Antispasmodic drugs
Laxatives/purgatives

Question 1

What do Antidiarrheal drugs and Antispasmodic drugs do?

Answer 1

Decrease motility or which decrease smooth muscle tone

Question 2

What do laxatives/purgative sod?

Answer 2

Accelerate the passage of food through the intestine

Question 3

What is acute diarrhea?

Answer 3

Sudden onset in a previously healthy perosn
3 days - 2 weeks
Self-limiting
Resolve without sequelae

Question 4

What are causes of acute diarrhea?

Answer 4

Microbial
Drug-induced
Nutritional

Question 5

What is chronic diarrhea?

Answer 5

Lasts for more than 3 weeks
Recurring passage of diarrhea stools, fever, loss of appetite, nausea, vomiting, weight loss and chronic weakness

Question 6

What are causes of chronic diarrhea?

Answer 6

Tumours
Diabetes
Hormonal (Hyperthyroidism, Addison’s disease)
IBS

Question 7

What are some antidiarrheal drugs?

Answer 7

Opioids
Adsorbents
Anticholinergics (antispasmodic)

Question 8

What is antidiarrheal opioids mechanism of action?

Answer 8

Activate opioid receptors in GI tract
-Decrease bowel motility
-Increasde bowel transit time
-Allows more time for water and electrolytes to be absorbed
-Decrease secretions and increase fluid absorption

Question 9

Examples of opioid antidiarrheals?

Answer 9

Loperamide (Imodium)
Others: diphenoxylate, paregoric, opium
tincture

Question 10

Describe loperamide?

Answer 10

Poorly absorbed
Poor access to CNS

Question 11

Adverse effects associated with antidiarrheal opioids?

Answer 11

Excessive doses can lead to typical opioid drug effects

Question 12

What do Adsorbents do?

Answer 12

Coat the walls of the GI tract
Bind to the causative bacteria or toxin, which is then eliminated through the still
Inhibit intestinal secretions

Question 13

Examples of adsorbents?

Answer 13

Bismuth subsalicylate (Pepto-bismol)
Activated charcoal

Question 14

What is Bismuth subsalicylate also used fro?

Answer 14

Relief of stomach acid symptoms

Question 15

What adverse effects are associated with Bismuth subsalicylate?

Answer 15

Constipation
Dark stools and tongue
Metallic taste
Blue gums

Question 16

Do not give Bismuth subsalicylate to who?

Answer 16

Children younger than age 16 or teenagers with viral infections e.g, chicken pox
-Reye’s syndrome

Question 17

What is the mechanism of action of antidiarrheal anticholinergics?

Answer 17

Antagonist at cholinergic receptors
Decrease diarrhoea muscle cramping

Question 18

Examples of antidiarrheal anticholinergics?

Answer 18

Atropine
Scopolamine (hyoscine)

Question 19

What are laxatives mechanism of action/

Answer 19

Bulk forming (1-3 days)
Osmotic (hyperosmotic; dose dependant)
Fecal softener (emollient; 1-3 days)
Stimulant (6-12 hours)

*All laxatives lead to softer stools

Question 20

Do not use laxatives if you have a ?

Answer 20

Bowel obstruction

Question 21

Overuse/absuse of laxative scan cause?

Answer 21

Atonic colon -reduced muscular activity (lazy colon)
Dependency sort of

Question 22

What are bulk forming laxatives?

Answer 22

High fibre substances (non-digestable material)
Absorbs water present in lumen to increase bulk
Distends bowel to initiate reflex bowel activity

Question 23

Examples of bulk forming laxatives?

Answer 23

Methylcellulose (citrucel)
psyllium (Metamucil)
Polycarbophil

Question 24

Bulk forming laxatives can also provide relief for what?

Answer 24

Diarrhea

Question 25

What are osmotic laxatives?

Answer 25

Non-absorbable compounds or salt solutions that draw water into intestinal lumen

Question 26

What can osmotic laxatives cause?

Answer 26

Substantial Water loss
-Dehydration

Question 27

What are the types of osmotic laxatives?

Answer 27

Hyperosmotic compounds
Salines (salt solutions)

Question 28

What do hyperosmotic compounds do?

Answer 28

Increase fecal water content
Bowel distention
Increased peristalsis and evacuation

Question 29

Examples of hyperosmotic compounds?

Answer 29

Lactulose
polyethyleneglycol (Restoralax)
sorbitol
glycerin (enema/suppository)

Question 30

What do salines do?

Answer 30

Increase osmotic pressure within the intestinal tract causing more water to enter the intestines

Bowel distension, increased peristalsis and evacuation

Question 31

examples of saline laxatives?

Answer 31

magnesium sulfates
Magnesium hydroxide
magnesium citrate
sodium phosphate enema (Fleet)

Question 32

For constipation how are osmotic laxatives administered?

Answer 32

low doses
6-12 hours

Question 33

For diagnostic and surgical preps how are osmotic laxatives administered?

Answer 33

High doses
e.g, water stool in 2-6h for a clean colon

Examples: PEG + Na/Mg salines (PegLyte)

Question 34

What do fecal softeners do? (emollients or surfactants)

Answer 34

Promote more water and fat ins tools
Lubricate the fecal material and intestinal walls

Question 35

Examples of fecal softeners?

Answer 35

Stool softeners: decussate sodium (enema)
Lubricants: mineral oil
enema options

Question 36

What do stimulant laxatives do?

Answer 36

Increases peristalsis via intestinal nerve stimulation
Increase fluid secretion into intestine

Question 37

Examples of stimulant laxatives?

Answer 37

Senna (enema/suppository options)
cascara
bisacodyl (synthetic; enema/suppository)
castor oil (only for rapid GI cleansing)

Question 38

Because opioids cause constipation what is used to prevent it?

Answer 38

Stimulants and fecal softener

Question 39

Clients taking bulk forming laxatives should do what?

Answer 39

Take with at least 240mL or water (full glass)
prevents oesophageal obstruction

Question 40

Clients should not take laxative sit they are experiencing what?

Answer 40

Nausea
Vomiting
and/or abdominal pain