28-29 - Myocardial Ischemia Agents

Question 1

What typically causes anginal pain?

Answer 1

The release of bradykinin and adenoside onto nociceptive afferents

Question 2

What are the factor that contribute to myocardial oxygen demand?

Answer 2

• Heart rate
• Contractility
• Preload
• Afterload

Question 3

What are the factors that contribute to myocardial oxygen supply?

Answer 3

• Coronary blood flow

- Regional myocardial blood flow

Question 4

Which drug classes function to decrease myocardial oxygen demand in the case of an acute MI?

Answer 4

• Beta adrenergic antagonists (beta blockers)
• Some Ca++ entry blockers
• Organic nitrites

Question 5

Which drug classes function to increase oxygen supply in the case of an acute MI?

Answer 5

• Vasodilators (especially Ca++ entry blockers)
• Statins
• Antithrombotics

Question 6

What is nitrate tolerance?

Answer 6

• When given acutely, nitrates have potent hemodynamic and therapeutic effects, however these effects were lost rapidly during sustained therapy
• * Drug effects were almost lost completely when significant plasma concentrations of nitrites were present*
• Tolerance develops early and CANNOT be overcome with higher doses

Question 7

What is the mechanism of nitrate tolerance?

Answer 7

Controversial

Question 8

How do you maintain the effect of nitrites and avoid nitrite tolerance?

Answer 8

Nitrate effects could be maintained using dosing regimens that allow for a nitrate-free or low-nitrate concentration for several hours each day.