Drug MOAs

Question 1

What is the MOA of Digoxin?

Answer 1

↓ HR, ↓ AV node conduction, +ve ionotropic

Question 2

MOA of Amiodarone?

Answer 2

Prolongs QT and PR intervals by slowing conduction through the AV and SA nodes

Question 3

Atenolol, Bisoprolol, Metoprolol MOA?

Answer 3

Competitively block beta 1 receptors, ↓HR, ↓BP, ↓ contractility, ↓ conduction

Question 4

What is the MOA of Carvedilol?

Answer 4

Blocks beta1&2 and alpha 1, ↓HR, ↓BP, ↓ contractility, ↓ conduction, also increase vasodilation due to alpha 1 activity

Question 5

Aspirin MOA?

Answer 5

Inhibits platelet aggregation by irreversibly inhibiting COX, this decreases the synthesis of thromboxane A2 (which is an inducer for platelet aggregation) for the life of the platelet

Question 6

What is the MOA for Clopidogrel and Ticagrelor?

Answer 6

Irreversibly binds to P2Y12 platelet receptors and inhibits platelet aggregation for the life of the platelet

Question 7

Heparin and Enoxaparin MOA

Answer 7

Inactivates clotting factors IIa (thrombin) and Xa by binding to antithrombin

Question 8

Warfarin MOA

Answer 8

Vitamin K antagonist. Inhibits synthesis of Vitamin K dependant clotting factors (2, 7, 9, 10) and the antithrombotic factor proteins C and S

Question 9

MOA of Dabigatran

Answer 9

Reversibly inhibit free and bound thrombin preventing conversion of fibrinogen to fibrin. Thrombin induced platelet aggregation is also inhibited

Question 10

What is the MOA of Rivaroxaban and Apixaban?

Answer 10

Selectively inhibit factor Xa, blocking thrombin production, conversion of fibrinogen to fibrin and thrombus development

Question 11

MOA of Perindopril and Ramipril

Answer 11

Works on the Renin/Angiotension pathway.
Blocks the conversion of angiotensin 1 to 2, also inhibits the breakdown of bradykinin.
Reduces the effects of angiotensin 2 mediated processes such as vasoconstriction, sodium retention and aldosterone release. ↓ BP

Question 12

MOA of Irbesartan

Answer 12

Competitively blocks binding of angiotensin 2 to ATR1.

↓ vasoconstriction, ↓ Na+ resorption, ↓ aldosterone release, ↓ BP

Question 13

Furosemide MOA

Answer 13

Loop diuretic. Inhibit resorption of Na+ in ascending loop of Henle to produce a rapid and intense diuresis

Question 14

MOA of Hydrochlorothiazide

Answer 14

Thiazide diuretic. Moderately potent diuretic, inhibit resorption of Na+ in the proximal segment of the distal convoluted tubule

Question 15

MOA of Spironolactone?

Answer 15

K+ sparing diuretic. Inhibit Na+ respiration in collecting duct by antagonising aldosterone. Blocks the sodium potassium pumps preventing Na+ from being ‘swapped’ for K+

Question 16

What is the MOA of Atorvastatin, Simvastatin and Rosuvastatin?

Answer 16

Competitively inhibit a rate limiting enzyme (HMG Co A) in cholesterol synthesis. Increase hepatic uptake of cholesterol and decrease total cholesterol

Question 17

MOA of the Dihydropyridies (Amlodipine and Lercanidipine)

Answer 17

Block inwards current of Ca2+ via L-type channels in arteriolar smooth muscle to reduce peripheral and vascular resistance and BP

Question 18

What is the MOA of the Non-dihydropyridies (Verapamil and Diltiazem)?

Answer 18

Act on cardiac smooth and arteriolar smooth muscle.
↓ cardiac contractility, ↓ HR, ↓ conduction.
Verapamil has a greater effect on the heart.