Chapter 46: vasodilators Flashcards
Agents that act primarily on the arterioles are called what?
Resistance vessels
Agents that act primarily on veins are what?
Capacitance vessels
What determines its hemodynamic effects and is a major determinant factor r/t both therapeutic and undesired effects?
Selectivity
What effect do arterioles have on afterload & cardiac workload
decrease in cardiac afterload & cardiac workload
What effects do arterioles have on cardiac output and tissue perfusion?
Increase in CO & tissue perfusion
What are some primary therapeutic uses of vasodialtors?
-Systemic & pulmonary HTN
-hypertensive crisis/pheochromocytoma
-angina pectoris/MI
-HF
-Peripheral vascular disease
What are 3 ADRs r/t vasodilation
-postural hypotension
-reflex tachycardia
-expansion of blood volume (w/ prolonged use)
Why would someone get postural hypotension r/t vasodilation
-relaxation of smooth muscle in the veins. gravity causes blood to pool. further decreases venous return. Decrease in CO & BP. Decreased ventricular pressure
Why would someone develop reflex tachycardia r/t vasodilation?
- direct reduction in arterial pressure.
-reduces CO. - can be due to arterial or venous dilation
What can you pretreat reflect tachycardia with?
Cardioselective beta blocker
What should pt use vasodilators with to prevent therapeutic effects from being cancelled out?
diuretics
What drug is a selective dilation of arterioles?
Hydralazine
if a person is takin hydralazine what would you notice about their arterial BP & peripheral resistance?
It falls
On hydralazine, a pts HR and contractility would do what?
Increase
What drug would you want to take with hydralazine to help with the cardiac effects?
Cardioselective beta-blocker (metoprolol)
hydralazine is inactivated by a metabolic process known as what?
Acetylation (rate is genetically determined)
What are 3 ADRs for hydralazine?
- reflex tachycardia
-increased blood volume
-systemic lupus erythematosus-like syndrome
What 2 drugs can hydralazine be combined with?
-diuretics
-beta-blockers
A pt comes in and is complaining of fever, muscle and joint pain, and has nephritis, pericarditis, and positive rheumatoid antibodies. What syndrome do they have and what should you do if they are taking hydralazine?
Systemic lupus erythematosus-like syndrome
Discontinue drug