second group - vasodilator medicines

Question 1

split into 5 groups

Answer 1

1. angiotensin converting enzyme inhibitors (ACEIs)
2. calcium channel blockers
3. nitrates
4. phosphor-diesterase inhibitors
5. A1 antagonists

Question 2

ACEIs

Answer 2

• ACE inhibitors prevent angiotensin II from being present, ensuring vasoconstriction won’t occur, therefore reducing workload of the heart
• mainly used to reduce afterload
• given through oral administration which are converted to active medicine with enzymes
• relatively safe, may have minor GI effects or hypotension

Question 3

calcium channel blockers

Answer 3

• e.g amlodipine and diltiazem
• negative inotropic agents and negative chonotropes
• used as antiarrhythmics and vasodilators
• block the amount of calcium in cells therefore reduce heart contractility
• causes vasodilation due to blocking calcium which also reduces afterload and improves blood flow
• side effects: decreased contractility, vasodilation, slow AV pulse

Question 4

nitrates

Answer 4

• e.g nitroglycerin (topical), nitroprusside (injectable), isosorbide dinitrate
• work to relax smooth muscle cells by increasing nitrate oxide production and activate cGMP
• reduces preload
• can cause hypotension

Question 5

phosphor-diesterase inhibitors

Answer 5

e.g pimobendan, slidenafil, tadalfil

Question 6

A1 agonists

Answer 6

e.g prazosin