Flashcards in Antihypertensives II Deck (32)
What are the alpha-adrenergic receptor blockers?
What do alpha-adrenergic receptor blockers cause?
Decreased peripheral vascular resistance
Decreased venous capacitance
What calcium channel is more important in smooth muscle?
Both L-type and T-type calcium current
What calcium channel is more important in cardiac muscle?
L-type calcium current
What do dihydropyridines inhibit?
ONLY T-type calcium current channels!
What are the only drugs that inhibit L-type calcium channels?
What inhibits T-type calcium channels?
How do calcium channel blockers work?
By decreasing the voltage of calcium channels so that they are not easily activated; effectively prolongs the inactivation time of the channels/refractory period
What do DHPs such as Nifedipine cause?
Reflex AV conductance
Why do DHPs cause a reflex in HR/contractility/AV conductance?
Because they cause vasodilation in the periphery but do not affect the L-type channels in the myocardium so the myocardium compensates
What are the DHPs?
What are the direct vasodilators?
What two ways does hydralazine work?
1.) Activates Ca-activated potassium channels in SM causing hyperpolarization
2.) Inhibits IP3-induced Ca release from SR in SM
How does Minoxidil work?
Activates ATP-dependent K channels causing hyperpolarization of SM cells
What are the aldosterone antagonists?
Where can the RAAS blockers block?
What are the renin antagonists?
What are the ACE inhibitors?
What are the A-II receptor antagonists?
What receptor does A-II bind and work on?
AT-1 (angiotensin 2 receptor type-I) angiotensin I does not affect a receptor
What does A-II cause?
Vasoconstriction and renin formation inhibition
What does A-III cause?
Activation of aldosterone and reabsorption of Na and water
What does renin do?
Cleaves angiotensinogen to angiotensin I
Three categories of diuretics:
What are the potassium sparing diuretics?
What are the thiazide diuretics?
What are the loop diuretics?
What are the first three drugs to start a patient with hypertension based on their ethnicities and co-morbidities?
1.) ACE inhibitor or A-I receptor antagonist
2.) Calcium entry blocker
3.) Thiazide diuretic
What antihypertensives do not work well on Africans?
ACE inhibitor or A-II