L11-Vasodilators Flashcards
What are the three main controllers of vasculature tone?
Autonomic innervation
Circulating hormones
Local mediators
What is the most important target for drugs affecting vasculature diameter?
Ca2+ is an important drug target
What are the two main types of vasodilators?
Direct- drugs that actually cause vasodilation
Indirect-drugs that work by blocking vasoconstriction
What are the two ways indirect vasodilators work?
By blocking the sympathetic nervous system
By blocking the RAAS
What are the ways that direct vasodilators work?
Inhibition of the voltage gated Ca2+ channels hence inhibiting contraction
How does sodium Nitroprusside work and what is it used to treat?
Works by releasing NO and hence is a vasodilator used to treat hypertension. Only really used in hypertensive emergencies
How does Minoxidil work and what is it used for?
It is used only for severe hypertension and works by K+ channel opening, this hyperpolarises the cell and makes it less likely that Ca2+ channels will open
What is the drug treatment of angina pectoris aiming to achieve?
Increase in coronary blood flow
Decrease in cardiac work (heart requires less O2)
What drugs are used to treat angina?
Beta blockers- to decrease cardiac work (not vasodilators)
Oraganic nitrates - Vasodilators so decrease venous return and cardiac work, also increase coronary blood flow
How do calcium channel blockers work and what is their effect?
They block L-type calcium channels and therefore cause vasodilation mainly in arteries. This has the effect of decreased TPR and decreased cardiac work
How can severe raynauds syndrome be treated?
With nifedipine
How do phosphodiesterase inhibitors work?
Work on particular receptors found mainly in genital tissue so works to cause erection.
