Medications

Question 1

Ondansetron MOA

Answer 1

Serotonin (5HT) is released from enterochromaffin cells ( stomach/ small intestine) in response to noxious stimuli
5HT3 receptors are activated, stimulating the vagus nerve and subsequently the vomiting centre
Ondansateron is a 5HT3 antagonist which interferes with this process at multiple sites ( stomach/ vagus nerve/ vomiting centre)

Question 2

Metoclopramide MOA

Answer 2

A highly effective but highly un- refined
Multiple sites of action, D2/ DA2 receptors (dopaminergic)
Serotonergic (5HT3), cholinergic (M1) and other interaction within the CNS
Serotonergic (5HT4) agonist effect and cholinergic effects also promote gastric emptying by inhibiting the relaxation of smooth muscle and increasing peristalsis which can be helpful in some circumstances

Question 3

Adrenaline

Answer 3

Mediated through beta 2 receptor that is found on surface of airway smooth muscle cells
Action is two pronged, firstly reduces the amount of cAMP, which decreases amount of calcium in cytoplasm, this reduction reduces the contractions

Question 4

Salbutamol

Answer 4

(beta 2 agonist)
Binds to beta 2 receptor, increasing Camp which reduces calcium and interferes with actin myosin interaction causing bronchodilation

Question 5

Ipatropium

Answer 5

muscarinic antagonist
Blocks muscarinic acetylcholine receptors causing decreased smooth muscle contractility resulting in bronchodilator and decreased respiratory tract secretions

Question 6

Atropine

Answer 6

When atropine binds to the M2 receptor it blocks the effects of acetylcholine, increases in cAMP level and increases in funny current and therefor heart rate and output

Question 7

Hydrocortisone

Answer 7

Alters interaction within the cell changing DNA processes which dampens the effect of the inflammatory response.
Blocks formation of arachidonic acid, reducing amount of late mediators released
Reduced function and activation of b cells and t helper cells

Question 8

Magnesium sulphate

Answer 8

Reduces calcium influx into cells producing skeletal and smooth muscle relaxation and reduced cardiac muscle contractility and excitability.
Smooth muscle relaxer and can alleviate bronchoconstriciton

Question 9

Lignocaine 1% nerve block

Answer 9

Blockage of voltage gated sodium channels on the internal surface of nerve cell membranes leading to a reversible prevention of nerve depolarisation

Question 10

Midazolam

Answer 10

Binds to gaba A receptors at different allosteric sites, this facilitates the action of gaba and enhances its inhibitory effects, increases opening of chloride channels and chloride floods into cell
Prevents depolarisation prevents action potential from continuing

Question 11

Mirtazapine

Answer 11

Blocks postsynaptic serotonin receptors and presynaptic auto receptors and H1 agonists

Question 12

Droperidol/ haloperidol

Answer 12

Antagonise D1 and D2 receptors, block dopamingeric transmission in various parts of the brain and leads to CNS depression

Question 13

Benzylpenicllin

Answer 13

Inhibits bacterial cell wall synthesis, inhibits the cross linking of the cell wall without cross links the cell wall is destroyed allows water to flow in and cells Burt’s and dies

Question 14

Ceftriaxone

Answer 14

Inhibits cell wall synthesis, is susceptible to gram positive and negative bacteria

Question 15

Statins

Answer 15

HMG COA reductase inhibitors
Reduce lipids by blocking the production of cholesterol in the liver

Question 16

Amiodarone

Answer 16

Interacts with sodium, calcium and potassium affecting the ion movement. Prolongs refractory period and duration of action potential, decreases sinus node automaticity, slows atrioventricular conduction
For VT & VF

Question 17

Adenosine

Answer 17

Simulates A1 receptors on atrium and on SA and AV node, pro kings refractory period increased potassium efflux and decreases calcium efflux. briefly stops electrical conductivity of the heart allowing SA nose to take over

Question 18

Digoxin

Answer 18

Inhibits sodium and potassium adenosine triphosphate pump in myocardium membrane leading to increased intracellular calcium, activated actin and myosin, greater force of contraction, shortens action potential, reduces av nodal conduction and decreased HR

Question 19

GTN

Answer 19

Interacts with vascular smooth muscles, converts to nitric oxide, increases levels of cGMP, reduces calcium levels, reduces actin and myosin interaction, relaxation of vascular smooth muscles and decrease in blood pressure

Question 20

Aspirin

Answer 20

Targets platelet aggregation phase, inhibits cycloxygenase, prevents synthesis of thromboxane and prostacyclin and other prostaglandins.
Reduces platelet activation, reduces recruitment reduces aggregation

Question 21

Clopigogeel

Answer 21

Targets platelet aggregation phase, ADP increases intracellular calcium levels via P2Y12 and P2Y1 receptors
Lowers calcium levels prevents shape change prevents degranulation

Question 22

Heparin

Answer 22

Binds to and enhances the ability of naturally occurring anti thrombin 3, deactivates factors 10a and 2a, deactivation interrupts fibrin formation

Question 23

Tenecteplase

Answer 23

Fibrinolytic agent, clever or degrades the fibrin dissolution of the clot

Question 24

Tranexamic acid

Answer 24

Synthetic derivative of lysine, binds to plasminogen, inhibits normal plasmin formation, slows breakdown of clots, helps prevent bleeding

Question 25

Frusemide

Answer 25

Decreased preload via preventing the reabsorption of water, increases urine output
Inhibits renal sodium reabsorption

Question 26

Insulin

Answer 26

Increase or restore the ability to metabolise glucose by enhancing glucose uptake

Question 27

Glucagon

Answer 27

Binds to glucagon receptors in the liver, activate cAMP, stimulate glycogenolysis, releases glucose from glycogen stores

Question 28

Oxytocin

Answer 28

Activates oxytocin receptors, increases calcium release, increase muscle contraction