Ischemic Heart Disease Drugs (details)

Question 1

What is the MOA of nitrates?

Answer 1

Nitrates mediate vasorelaxation (venodilation and arteriolar dilation, which reduces preload and afterload respectively), thus reducing oxygen consumption and thus relieves angina

Question 2

What are the 2 routes of administration of glycerol nitrates?

Answer 2

1) Sublingual
2) Transdermal

Question 3

What are the PK properties of the sublingual glycerol nitrate?

Answer 3

Shorter onset of action and duration of action compared to the transdermal glycerol nitrate

Question 4

What are the PK properties of the transdermal glycerol nitrate?

Answer 4

Longer onset of action and duration of action compared to the sublingual glycerol nitrate

Question 5

Which of the 2 types of glycerol nitrates is used for acute treatment of angina, and which is used for prophylaxis?

Answer 5

Sublingual for acute treatment
Transdermal for prophylaxis (usual maintenance)

Question 6

What is the route of administration of ISMNs and ISDNs?

Answer 6

Oral for both

Question 7

Are ISMN/ISDNs used for acute attacks or prophylaxis and why?

Answer 7

They are both used for prophylaxis because of their long onset of action.

Question 8

What are the clinical uses of ISMNs/ISDNs?

Answer 8

1) Prohylaxis for angina pectoris
2) Treatment of heart failure

Question 9

What are the PD features of ISMN/ISDNs?

Answer 9

1) Low dose = venous dilation, High dose = dilation of arteries + veins
Therefore can adjust dosing to decrease preload and/or afterload accordingly
2) Reduces end diastolic pressure and volume –> lowers intramural pressure –> improvement in subendocardial blood flow + direct dilatory effect on coronary arteries

Question 10

What are the adverse effects of nitrates?

Answer 10

1) Reflex tachycardia
2) Hypotension
3) Headache

Question 11

What is the MOA of beta blockers for ischemic heart disease?

Answer 11

Control of beta 1 receptor –> reduce contractility –> reduce O2 consumption

Question 12

DHPs and non-DHPs have higher affinity for calcium channel blockers on cells found where?

Answer 12

DHPs have higher affinity for calcium channels which are found on cardiac myocytes and hence work directly on the heart

Non-DHP calcium channel blockers have a higher affinity for calcium channels which are expressed on smooth muscles and the electrical circuits of the heart

Question 13

What are the clinical uses of calcium channel blockers

Answer 13

1) Antiarrhythmia (non-DHPs)
2) Anti-angina (non-DHPs & DHPs)
3) Anti-hypertension (DHPs)
Amlodipine reduces the risk of myocardial infarction and stroke

Question 14

What is the relative specificities of the DHPs and non-DHPs in lowering BP?

Answer 14

verapamil = diltiazem = nifedipine

Question 15

What is the relative specificities of the DHPs and non-DHPs as vasodilators?

Answer 15

nifedipine > diltiazem > verapamil

Question 16

What is the relative specificities of the DHPs and non-DHPs as cardiac depressants?

Answer 16

verapamil < diltiazem < nifedipine

Question 17

What are the adverse effects of calcium channel blockers?

Answer 17

Cardiac depression: bradycardia, AV blocker, heart failure, myocardial infarction, hypotension

Question 18

In what situation are calcium channel blockers contraindicated?

Answer 18

Heart failure

(because calcium channel blockers reduce the contractility of the heart and the rate at which the SA node fires and AV node conducts, which TLDR means that they affect the function of the heart, so they would end up having the heart failure worse)

Question 19

What are the clinical indications of ivabradine?

Answer 19

1) Stable angina pectoris
2) Chronic heart failure with systolic dysfunction, in patients with sinus rhythm and whose heart rate is more than or equal to 75 bpm

Question 20

What is the MOA of ivabradine?

Answer 20

Inhibition of the cardiac pacemaker current that controls the spontaneous diastolic depolarisation in the SA node and regulates heart rate –> Reduction in cardiac workload and myocardial oxygen consumption

Question 21

What are the adverse effects of ivabradine?

Answer 21

1) Visual problems: luminous phenomena (ie: transient enhanced brightness in a limited area of the visual field)
2) Dizziness (related to bradycardia)
3) Other bradycardia associated symptoms (hypotension, fatigue, malaise)