Pharmacodynamics

Question 1

Adrenaline

Answer 1

Adrenaline is a sympathomimetic which stimulates both alpha and beta adrenergic receptors.

Has positive inotropic (increase heart-contraction) and chronotropic (change the heart rate).

Agonist of both alpha and beta receptors (α1, β1, β2)

α1- arteries vasoconstriction effect

β1-heart inotropic & chronotropic effect

β2-lungs bronchodilation effect

Question 2

Atropine Sulphate

Answer 2

An acetylcholine (Ach) antagonist.
Anticholinergic & Antimuscarinic agent.

Blocks the action of Ach receptor sites at the SA node.
SA node will revert to its normal rhythm of 60-100 (normocardic).

Question 3

Amiodorane Hydrocloride

Answer 3

Class III antiarrhythmic

Primary effect is to block potassium (K+) channels.It also inactivates sodium (Na+)and calcium (C).

Prolongs phase 3 of the cardiac action potential.

Question 4

Aspirin

Answer 4

Blocks COX 2 which is used in the synthesis of thromboxane (a product made by platelets to make blood clot).

Aspirin inhibits platelet activation so it’s an anti-platelet.