MoA_All drugs

Question 1

Fluoxetine enhances effects of which receptors?

Answer 1

5HT1A autoreceptors

Question 2

What receptors does Clozapine affect?

Answer 2

D1, D2, 5HT2A, Alpha1 adrenoreceptors and muscarinic receptors

Question 3

High level mechanism of action for Lithium?

Answer 3

interacts with a number of neurotransmitters and receptors
decreases norepinephrine release
increases serotonin synthesis
Affects glutamate (>glutamate = mania,

Question 4

What receptors does Benzodiazepines affect?

Answer 4

Enhances GABAa receptors

Question 5

How do B.F.Ls work?

Answer 5

Soluble fibre
retain fluid in stool (swell)
increase faecal mass
stool softening properties

Question 6

How do Osmotic Laxatives work?

Answer 6

Increase fluid in large bowel
produces distension
Stimulates peristalsis

Question 7

How does lactulose work?

Answer 7

Disaccharide
broken down into lactic acid
increases osmotic pressure
increases stool water content and softens it

Question 8

How do PEG/Macrogols work?

Answer 8

Osmotic agent
cause excess water to be retained in the stool
stimulate peristalsis

Question 9

How do stimulant laxatives work?

Answer 9

Increase peristalsis

Stimulate either colonic nerve or both colonic and rectal nerves

Question 10

How do PPIs cause a reduction in acid?

Answer 10

Irreversibly bind with Proton pump. Inhibit H+/K+ ATPase enzyme system at secretory surface of gastric parietal cells

Question 11

How do dopamine antagonists work to prevent nausea?

Answer 11

Affinity for D2 and D3 receptors in CTZ and gastric tract.
GI emptying adjunct
Peristaltic stimulant

Question 12

How does H1 Receptor antagonist work to prevent nausea?

Answer 12

Depresses labyrinth excitability
Depresses vestibular stimulation
prevents transmission of muscarinic acetylcholine signal affecting the CTZ and vomiting centre

Question 13

How do 5HT3 receptor antagonists prevent nausea?

Answer 13

Target 5HT3 receptors at CTZ and gastric level
At gastric level, enterochromaffin cells produce serotonin in response to cytotoxic agents, serotonin binds to 5HT3 receptors on vagal afferent nerve sending signal to CTZ. 5HT3 receptors block this signal

Question 14

How do NSAIDs have a analgesic action?

Answer 14

Block synthesis of Prostaglandins through targeting of COX-1 as well as COX-2. PGE in particular have a role in pain by making nociceptors more sensitive to substances such as Bradykinins (inflammatory mediators produced by cells).

Question 15

What are the metabolic effects of prednisolone?

Answer 15

Stimulates gluconeogenesis
Reduces cellular uptake of blood glucose
Stimulates fat breakdown in adipose
Increased breakdown of proteins and mobilisation of amino acids

Question 16

What are anti-inflammatory and immune suppressive actions of prednisolone?

Answer 16

Inhibits prostaglandin synthesis
reduces action and proliferation of immune cells (lymphocytes, macrophages and eosinophils)
Reduces release of inflammatory mediators
Reduced production of immunoglobulins

Question 17

Vinca alkaloid agents exert cytotoxic action by ?

Answer 17

Inhibiting microtubule assembly, preventing spindle formation during mitosis.

Question 18

Alkylating agents exert cytotoxic action by

Answer 18

Cross linking of DNA bases; interfering with DNA replication

Question 19

Cytotoxic antibiotics exert cytotoxic action by

Answer 19

Interfering with enzymes involved in DNA replication

Question 20

How does insulin work?

Answer 20

Binds to receptor and triggers cascade leading to GLUT1-4 transporters moving to cell membrane allowing free flow of glucose into the cells

Question 21

What areas of metabolism does insulin influence?

Answer 21

Carb metabolism - increases uptake of glucose in liver, fat and muscle cells
Fat metabolism - causes increase in triglycerides (fat storage) (fatty acids plus A-glycerophosphate)
Protein metabolism - increases transport of amino acids into cells and synthesising protein within cells

Question 22

Which hormone in protein metabolism does insulin potentiate?

Answer 22

growth hormone

Question 23

What is prednisolone?

Answer 23

A glucocorticoid receptor agonist

Question 24

How does metformin work?

Answer 24

Decreases Glycogenolysis (Hepatic glucose production)
Decreases intestinal absorption of glucose
Improves peripheral insulin sensitivity

Question 25

Which glucose transporter does metformin affect?

Answer 25

activates AMPk (AMP activated protein kinase) a liver enzyme
This in turn causes GLUT 4 deployment to cell membrane

Question 26

How do ACE inhibitors work?

Answer 26

Block Angiotensin converting enzyme
In turn prevents AT1 being converted to AT11
AT11 causes vasoconstriction and break down Bradykinins which are vasodilators
By blocking AT11 causes an increase in bradykinins - dry cough
ATII also increases production of aldosterone which leads to increase in water retention so inhibiting aldosterone means less water is retained

Question 27

What is chronotropy?

Answer 27

Heart rate

Question 28

What is inotropy?

Answer 28

Contractility

Question 29

What is dromotropy?

Answer 29

Electrical conduction

Question 30

What is lusitropy?

Answer 30

Relaxation

Question 31

Where in the kidney to Thiazide diuretics work?

Answer 31

Distal convoluted tubule

Question 32

How do Thiazides cause a diuretic effect?

Answer 32

Inhibit action of transporter blocking reabsorption by blood of NaCL
The increase in Na in the tubule of the nephron affects K+ and H+ exchange leading to an increased secretion of K+ and potentially risking Hypokalaemia