4.6 Antianginal Drugs

Question 1

What is angina pectoris a symptom of?

Answer 1

coronary heart disease

Question 2

Angina pectoris presents as a sudden, sevre, pressing chest pain resulting from…

Answer 2

myocardial ischemia

Question 3

With Angina Pectoris the imbalance in oxygen demand may be due to what 3 things?

Answer 3

• Exercise
• A spasm of a vascular muscle
• Obstruction of blood vessels (atherosclerosis)

Question 4

What type of angina is characterized by chest pain precipitated by some activity, minimal or non-existent symptoms at rest?

Answer 4

Stable Angina

Question 5

What type of angina is characterized by, chest pain that occurs at rest, and with an increase in the severity, frequency, and duration in patients with previously stable angina?

Answer 5

Unstable angina (acute coronary syndrome)

Question 6

What type of angina is characterized by chest pain caused by a spasm of a coronary artery?

Answer 6

Variant angina (vasospastic angina)

Question 7

What are the organic nitrates used to treat angina? (3)

Answer 7

• Nitroglycerin
• Amyl nitrite
• Isosorbide dinitrate

Question 8

What are the calcium channel blockers used to treat angina? (3)

Answer 8

• Dihydropyridines
• Verapamil
• Diltiazem

Question 9

What are the beta-blocking drugs used to treat angina?

Answer 9

• Propranolol
• Atenolol
• Metoprolol

Question 10

What are the newer drugs used to treat angina? (2)

Answer 10

• Ranolazine
• Trimetazidine

Question 11

What organic nitrate is used as a 1st line for acute angina pectoris attacks?

Answer 11

Nitroglycerine

Question 12

What can nitroglycerine be comined with to increase its efficacy?

Answer 12

beta-blockers

Question 13

What organic nitrate is useful in treating cyanide poisoning?

Answer 13

Amyl nitrite

• Nitrite converts hemoglobin to methemoglobin which has a high affinity for cyanide
• Sodium nitrite is an antidote for cyanide

Question 14

How is amyl nitrite administered?

Answer 14

inhalation

Question 15

Which organic nitrate is long-acting, and why?

Answer 15

Isosorbide dinitrate

• Through its metabolite mononitrate

Question 16

How is isosorbide dintrate administered?

Answer 16

orally

Question 17

What vascular smooth muscle is more sensitive to organic nitrates?

Answer 17

Veins

• Arteries require a higher concentration
• Epicardial coronary artery also responsive

Question 18

What are the effects of nitrates on platelets? (2)

Answer 18

• Decrease in platelet aggregation
• Useful in treating unstable angina

Question 19

What are the toxicity effects of nitrates? (2)

Answer 19

• Throbbing headache
• Orthostatic hypotension
  
  • b/c they are vasodilators, which reduce BP

Question 20

Where do CCBs bind?

Answer 20

Alpha 1 L-type calcium channel

• Verapamil + diltiazem bind to 1 region
• Dihydropyridines (nifedipine) binds to another region

Question 21

Which CCB is a more selective vasodilator and may cause reflexed increase in HR?

Answer 21

Dihydropyridines (nifedipine)

Question 22

Which CCBs is cardiac muscle sensitive to?

Answer 22

Verapamil + Diltiazam

Question 23

What is the effect of CCBs on cardiac muscle?

Answer 23

• Dec in contractility, dose-dependently
• Dec in CO

Question 24

What CCB is vascular smooth muscle more sensitive to?

Answer 24

nifedipine

Question 25

What vascular smooth muscle is more sensitive to CCBs (nifedipine)?

Answer 25

Arteries

Question 26

What effect do CCBs have on vascular smooth muscle?

Answer 26

Dec in **peripheral resistance**

Question 27

What CCBs are cerebral blood vessels sensitive to?

Answer 27

Verampamil + nicardipine (another dihydropyridine)

Question 28

What toxicity is verapamil more so the cause of?

Answer 28

Serious cardiac depression * Bradycardia, av block, cardiac arrest, heart failure

Question 29

What toxicity is nifedipine more so the cause of?

Answer 29

**Reflex tachycardia** * Increasing the risk of MI in pts with HTN

Question 30

What is the effect of combining verapamil with beta-blockers?

Answer 30

more cardiac depression = bad

Question 31

What is the effect of combining nifedipine with beta-blockers?

Answer 31

**Complementary** to beta-blockers * nifedipine causes reflex tachycardia and beta-blockers prevent reflex tachycardia

Question 32

What are beta-blocking drugs extremely useful in the management of?

Answer 32

**Stable angina** * By dec HR, BP + contractility which reduces the myocardial oxygen demand

Question 33

In what type of angina is the use of beta-blockers questionable?

Answer 33

Variant Angina * b/c it is caused by spasms

Question 34

What is the toxic effect of giving an initial high dose of beta-blockers?

Answer 34

Heart failure

Question 35

What is the toxic effect of sudden withdrawl of beta-blockers?

Answer 35

Rebound **overstimulation of the heart** * Once you block these receptors the heart responds by expressing more receptors * When BB are withdrawn catecholamines are binding to all of these extra receptors = overstimulation of the heart

Question 36

What class of antianginal drugs have the toxic effect of worsening asthma?

Answer 36

Beta-blockers

Question 37

What is the mechanism of action of Ranolazine?

Answer 37

**Sodium channel-blocker** * Interfering with the Na-Ca exchanger * Depression of intracellular [Ca] * **Reducing heart contractility** and work

Question 38

What is the mechanism of action of Trimetazidine?

Answer 38

Metabolic modulator, shifting myocardial metabolic pathway by **​inhibiting fatty acid oxidation**

Question 39

What drug can trimetazidine be combined with to tx angina?

Answer 39

nifedipine