GI Pharmacology

Question 1

Why do patients get constipate? The mechanism behind constipation

Answer 1

Decreased peristalsis which could be a result of medication or age etc

Question 2

Give an example of medication which can contribute to constipation?

Answer 2

Opioids

Question 3

What is senescence?

Answer 3

the condition or process of deterioration/downregulate with age

Question 4

Why are older people more likely to have constipation?

Answer 4

process of senescence

Question 5

What are the 2 forms of laxatives?

Answer 5

Bulk laxatives

irritant laxatives

Question 6

What are the 2 types of bulk laxatives?

Answer 6

hydrophillic gels

osmotically active laxatives

alcohol and dissacharide based laxatives

Question 7

Where in the GI tract are faeces found?

Answer 7

colon and rectum

Question 8

What’s the name of the dehydratable slime in the small intestine?

Answer 8

chyme

Question 9

What are the characteristic of bulk forming laxatives?

Answer 9

Insoluble

non-absorbable, cannot permeate through epithelial gut lining

Question 10

Describe how bulk forming laxatives work

Answer 10

contains large macromolecules which increases coloidal pressure in the intestine thus drawing more water into intestine.

Form larger, softer stool which activate stretch receptors in the bowel, causing it to contract and relax moving bolus of faeces forward.

Question 11

Before administering bulk laxatives to a patient, what must you ensure about the patient’s condition?

Answer 11

That they are thoroughly hydrated otherwise, insufficient amount of water will be drawn into the stool

Question 12

List examples of hydrophilic gell bulk forming laxatives

Answer 12

Bran

Ispaghula Husk

Methyl cellulose

Sterculia

Question 13

What is the name of the nerve fiber network which is solely found in the GI tract and controls it’s motility?

Answer 13

Myenteric Plexus

Question 14

How many muscle layes are in the GI tract and what are they called

Answer 14

2 muscle layers,

Circular and Longitudinal

Question 15

Where is the Myenteric plexus found?

Answer 15

In the GI tract, sandwhiched between the circular and longitudinal muscle layers.

Question 16

What is the Myenteric plexus?

Answer 16

nerve fiber network which is solely found in the GI tract and controls it’s motility

Question 17

What does the efficacy of bulk laxatives (hydrophillic gel) laxatives depend on?

Answer 17

Patient being hydrated

Question 18

What are osmotically active

bulk forming laxatives?

Answer 18

Made up of epsom salts or glauber salts which increase osmotic pressure in the bowels.

Question 19

What are the contraindications for epsom salts for laxative use?

Answer 19

Renal Failiure

Question 20

What are the contraindications for Glauber salts?

Answer 20

Hypertension

Heart Failiure

Oedema

Question 21

What is the name of the dissacharride found in Macrogol?

Answer 21

polyethylene glycol

Question 22

Why does macrogol contain electrolytes aswell?

Answer 22

Reduces possibility of electrolyte imbalance and dehydration

Question 23

What is addes to macragol to help reduce possibility of electrolyte imbalance and dehydration?

Answer 23

electrolytes

Question 24

Why is Lactulose a useful laxative for those wth hepatic failiure?

Answer 24

Acidifies intestine and destroys gut flora to stop production of ammonia gas and ammonium ions.

Question 25

Which laxative should be indicated for someone with hepatic failiure?

Answer 25

Lactulose

Question 26

What is the mechanism of stimulant laxatives?

Answer 26

Irritates mucosal layer of GI tract causing reabsorbtion of electrolytes resulting in some fluid to enter. Irritation of mucosal layer also triggers irritation of muscle layer which cause the muscles to contract

Question 27

Why should you not give someone with a bowel obstruction laxative? especilly stimulant laxatives?

Answer 27

Forfully contracting the bowels on an obstruction can potentially cause a rupture

Question 28

What are the potential cause for decreased peristalsis?

Answer 28

medication -opiods spinal injury bowel obstruction

Question 29

What are the two elements for controlling the passing faeces?

Answer 29

autonomic and somatic control

Question 30

How long does it normally take for an empty colon to fill?

Answer 30

24-48 hours

Question 31

How does a patient develop laxative dependence?

Answer 31

Patient takes laxative without allowing time for faeces to move down colon. results in expulsion of material from ascending and transverse colon. Patient loses water and electrolytes because of this which dehydrates patient. Retention of sodium due to dehydration results in loss of potassium. Low potassium (hypokalaemia) means reduces peristalsis since potassium is integral for the contraction of muscle. This in turn means that the patient will need to take more laxatives

Question 32

Which laxative is less likely to result in laxative dependence?

Answer 32

movicol

Question 33

How do we prevent the occurence of laxative dependence on patients?

Answer 33

Educate patients on the use of laxatives: explain it will trake longer for the patient to defecate afterwards. Ensure that the patient is thoroughly hydrated awareness that it may take a while to get

Question 34

What are the indication for laxative use?

Answer 34

Preperation for surgery/bowel pathology (bowel prep) constipation

Question 35

Which groups need to be give special consideration before administering laxatives?

Answer 35

Older people young children

Question 36

According to Paediatric guidelines, what should be the first line laxative given to a paeds patient?

Answer 36

polyethylene glycol 3350 (movicol) +elecetrolytes. May be mixed in with a cold drink

Question 37

What should be administered to a paeds pateient if after giving a first line laxative disimpaction does not occur?

Answer 37

A stimulant laxative

Question 38

when should a stimulant laxative be administered to a paeds patient if first line laxative does not work?

Answer 38

2 weeks if disimpaction does not occur

Question 39

What is the nurse role in terms of caring for a p[atient taking laxatives?

Answer 39

Assessing their need for laxatives Monitoring the patient whilst they are on laxative medication Evaluate the patients cureent situation to develop care

Question 40

Which cells in the stomach secrete gastric acid?

Answer 40

The parietal cells in the inner lining of the stomach

Question 41

What substances are secreted by parietal cells?

Answer 41

HCL (gastric acid) and intrinsic factors

Question 42

What is the purpose of gastric acid interms of digestion?

Answer 42

activates enzymes required for digestion

Question 43

What is another term (scientific) for indigestion?

Answer 43

dyspepsia

Question 44

List the types of acid reducing medications you need to know for the exam

Answer 44

Antacids H-2-receptor anatagonists - HR2 As Proton pump inhibitors-PPIs

Question 45

What are the consequences of giving acid reducing medication?

Answer 45

affects homeostasis of the digestive system

Question 46

Which part of the GI tract is acidic fat-soluble likely to absorbed and why?

Answer 46

The stomach because it is an acidic environment

Question 47

How do Antacids work?

Answer 47

They are basic and help neutralise the acid in the stomach.