Cardiac drugs

Question 1

How does aspirin work?

Answer 1

Irreversibly acetylates COX

This prevents production of prostaglandin H2, which then can’t be cleaved into thromboxane A2

Question 2

What does aspirin-caused inhibition of thromboxane A2 production cause?

Answer 2

Inhibition of platelet aggregation

Question 3

What typical dose of aspirin will be prescribed?

Answer 3

75mg or 100mg /24hrs

Question 4

How does clopidogrel work?

Answer 4

ADP receptor antagonist

Question 5

What is the other molecule that prostaglandin H2, the product of COX, is cleaved into?

Answer 5

12-HHT

Question 6

Is it significant that aspirin also inhibits the production of 12-HHT?

Answer 6

Potentially

12-HHT has been shown to be protective against the effects of thromboxanes by antagonising the thromboxane receptor

Potentially not important though, because there is no need to antagonise the effects of thromboxane if there is no thromboxane anyway!

Question 7

When would you look to use clopidogrel instead of aspirin?

Answer 7

If the patient has gastric irritation with aspirin, or any other ADR

Also after stent insertion, or if the patient has ACS, a TIA or CVA while on aspirin

Question 8

What drug appears to be as good as warfarin in preventing thrombus formation in AF?

Answer 8

Rivaroxaban

Question 9

Does rivaroxaban cause less bleeding than warfarin?

Answer 9

Yes

But it causes more bleeding in the GIT

Question 10

What is the mechanism of action of rivaroxaban?

Answer 10

Factor Xa inhibitor

Question 11

What studies showed that rivaroxaban can be used as VTE prophylaxis after hip/knee surgery?

Answer 11

RECORD1, 2, 3 and 4

Question 12

Can rivaroxaban be used to prevent stroke, and if so what study showed that?

Answer 12

Yes

ROCKET-AF

Question 13

What study showed that rivaroxaban can be used in secondary prevention of major cardiovascular events after ACS?

Answer 13

ATLAS

Question 14

Is rivaroxaban given orally or subcut?

Answer 14

Orally