4.2 - Anti-Anginal Drugs

Question 1

What are the three classes of anti-anginal drugs?

Answer 1

–> Nitrates
–> Beta-blockers
–> (Voltage-sensitive) Calcium Channel Blockers

Question 2

What are nitrates?

Answer 2

Drugs derived from nitroglycerin - a volatile and explosive compound used in the manufacturing process and dynamite

In pharmaceutical preparations, these chemical have been stabalized

Question 3

Nitroglycerin:
–> Tmax / T1/2
–> Metabolism

Answer 3

Tmax: 30 seconds
T1/2: 2 mins

Significant first pass hepatic effect

Question 4

Isosorbide mononitrate:
Tmax/ T1/2?
Route?

Answer 4

Tmax: 1 hr
T1/2: 45 mins
Route is p.o.

Question 5

What is the route of nitroglycerin administration?

Answer 5

Sublingual (Tablet or aerosol)

Transdermal
–> Be aware of tolerance

Topical ointment

I.v

oral
–> Extensive first pass hepatic betabolism

Question 6

What is the mechanism of action of nitrates?

Answer 6

Vasodilation of:
Veins
–> Decreased venous return; Decreased preload

Arterioles
–> Drop in BP; decreased resistance and decreased afterload

Coronaries
–> Increased coronary bloodflow

Question 7

What are some adverse effects of nitrates?

Answer 7

–> Orthostatic hypotension (w reflex tachycardia at high doses)
–> Frequent headaches, especially at the beginning of treatment
–> Tachyphylaxis (tolerance) when continuously exposed to drug

Question 8

What does chronotropic mean?

Answer 8

Related to heart rate

Question 9

What does inotropic mean?

Answer 9

Related to force of heart contraction

Question 10

What does dromotropic effect mean?

Answer 10

Related to conduction velocity in the heart

Question 11

How do beta blockers affect the heart?

Answer 11

They demonstrate negative chronotropic, inotropic, and dromotropic effects on the heart.

Question 12

How do beta blockers effect the kidneys?

Answer 12

They decrease renin release by juxtaglomerular cells
–> Less AngII, therefore lower BP.

Question 13

How do beta blockers treat angina?

Answer 13

Decrease heart rate and contractility = therefore decrease in oxygen consumption by the heart

Decrease in afterload d/t decreased blood pressure.

Question 14

Which beta blockers are cardio-selective? What does this mean?

Answer 14

Metoprolol, bisoprolol, atenolol, acebutolol
–> Acts mostly on beta 1 (Cardiac)

Question 15

Why would you use a non-specific beta blocker like propranolol?

Answer 15

It is very lipid soluble
–> Allows it to cross cell membranes and have access to the brain, it is therefore used for anxiety and migraines

Question 16

What does ISA (intrinsic sympathomimetic activity) mean?

Answer 16

In blocking, they also have agonist activity
–> Such as when we want to protect the tissue form overactivation but don’t want a complete blockage

Question 17

Which cardioselective beta blocker has Intrinsic sympathomimetic activity (ISA)?

Answer 17

Acebutolol

Question 18

Which non-cardioselective beta blocker has Intrinsic sympathomimetic activity (ISA)?

Answer 18

pindolol

Question 19

What are the therapeutic effects of beta blockers?

Answer 19

Treatment of:
–> Angina, hypertension, arrythmias, heart failures

–> Migraines, anxiety (lipid soluble)

–> Hyperthyroidism

Question 20

What are the three sub-classes of calcium channel blockers?

Answer 20

Dihydropyridines

Non-dihydropyridines
–> Benzothiazepines
–> Phenylalkylamines

Question 21

What are the dihydropyridines?

Answer 21

Amlodipine, nifedipine

Question 22

Name a benzothiazepine.

Answer 22

Diltiazem

Question 23

Name a phenylalkylamine

Answer 23

Verapamil

Question 24

Which calcium channel blockers have vascular effects? What are they?

Answer 24

Amlodipine, Nifedipine, verapamil, diltiazem
–> Arterial vasodilation (decrease in BP, afterload)
–> Coronary artery vasodilation/reduction of vasospasms

Question 25

Which calcium channel blockers have cardiac effects?

Answer 25

The non-dihydropyridines (diltiazem, verapamil)
–> Negative inotropic effect (decreased force of contraction)
–> Decreased heart rate

Question 26

What are the adverse effects of calcium channel blockers?

Answer 26

–> Headaches
–> Flushing
–> Edema in lower limbs
–> Orthostatic hypotension
–> Constipation (verapamil)

Question 27

What are the therapeutic effects uses of calcium channel blockers?

Answer 27

Treatment of:
–> Angina
–> HTN (Amlodipine, Diltiazem, Nifedipine)
–> Arrythmias (non dihydropyridines - Diltiazem, Verapamil)