Vasodilators And Statins

Question 1

What causes angina?

Answer 1

Atherosclerotic plaques In vessel walls that limit coronary blood flow and supply of oxygen to the myocardium

“this won’t come up” - colm kennedy

Question 2

How do antianginal drugs reduce myocardial oxygen demand?

Answer 2

• Decreasing heart rate (Beta-blockers, Ivabradine)
• Reducing cardiac contractility (Beta-blockers)
• Reducing ventricular wall tension (CCBs, nitrates, ranolazine)

Question 3

What are organic nitrates, what are they used for and what two types are there?

Answer 3

Esters of nitric acid.
Used to prevent and treat angina attacks
Short-acting - treats acute attack, long-acting - provides long term protection against attacks

Question 4

What are the two main examples of organic nitrates?

Answer 4

Glyceryl trinitrate and isosorbide dinitrate/moninitrate

Question 5

What formulations of glyceryl trinitrate are available and which ones are short and long acting?

Answer 5

Short acting - sublingual or buccal
Long acting - transdermal and oral

Question 6

What are the side effects of organic nitrates?

Answer 6

• Tolerance
  
  • Aldehyde dehydrogenase depletion - needs time to regenerate
• Headache, dizziness, hypotension
• Reflex tachycardia
  
  • prevented by use of a beta blocker concomitantly

Question 7

What are the advantages of the vasodilators Nicorandil and Minoxidil over organic nitrates?

Answer 7

• Have both arterial and venous vasodilating properties
• Does not possess tolerance issues

Question 8

What are the disadvantages of Nicorandil and Minoxidil?

Answer 8

• Similar adverse effects to nitrates
• Minoxidil -> Cam cause excessive hair growth, especially in women

Question 9

What is Ranolazine used for and who is it especially useful for?

Answer 9

First line adjuctive agent for chronic stable angina, useful in patients with severe heart failure / low blood pressure

Question 10

What is the indication for Ranolazine?

Answer 10

Adjunct therapy In stable angina inadequately managed/intolerant to first line antianginals (B blockers/CCBs)

Question 11

What is the indication and mechanism of action of Ivabradine?

Answer 11

Angina and heart failure.
Decreases heart rate by blocking the If current in the sinoatrial node

Question 12

What is the important drug class that treats hypercholesteraemia and what enzyme do they inhibit?

Answer 12

Statins, that inhibit HMG-CoA reductase (structurally similar) in cholesterol biosynthesis

Question 13

What are the advantages of Type 2 statins (e.g. Atorvastatin) over type 1 (e.g. Simvastatin)

Answer 13

• Easier to synthesise (larger)
• Form more robust interactions with HMG-CoA reductase
• Longer half life

Question 14

What are the side effects of statins?

Answer 14

GI issues, hepatotoxicity (Mainly in liver disease)
SERIOUS: myalgia (muscle pain), rhabdomyolysis (Little cholesterol in muscle -> toxic metabolite release)

Question 15

What are examples of bile acid-binding resins?

Answer 15

Colestipol, Cholestyramine, and Colesevelam

Question 16

What is the mechanism of action of bile acid-binding resins (Cholestipol, Cholestyramine, Colesevelam)

Answer 16

1. They have Cationic resins (have amine groups) that bind to the anionic bile acids
2. Unable to reabsorb bile as resins are large
3. Liver must recruit cholesterol to resynthesise bile acid

Question 17

What is the main drug which is a cholesterol absorption inhibitor?

Answer 17

Ezetimibe

Question 18

What are two examples of Fibrinic acid derivatives (fibrates) and how do they work?

Answer 18

Gemfibrozil and fenifibrate.
Reduce serum levels of triglycerides and LDL-C while raising levels of HDL-C