Antihypertensives Flashcards
What is the BP range for pre-hypertension?
120-139/ 80-89
What is stage 1 hypertension?
140-159/ 90-99
What is stage 2 hypertension?
> 160/ >100
What is heart or pump-based hypertension?
more common in young with hyperkinetic circulation (increased sympathetic nervous system) with increased CO and normal peripheral resistance.
What is vascular-based hypertension?
increased peripheral resistance with age, vasoconstriction, and normal CO
What is renal/volume-based hypertension?
increased Na+/H2O/fluid retention and increased RAAS/CO/peripheral resistance
What are some other causes of hypertension (HTN)?
hyperthyroidism, pheochromocytoma, hyperaldosteronism
How does increased Na+ concentration lead to hypertension?
increased Na+ inside sm. muscle leads to increased Ca++ (due to Na+/Ca++ exchanger), increasing sensitivity to NE/EPI/Ang II, thus increasing vasoconstriction and peripheral resistance
*Thus using Na+ restriction/ diuretics will lower these effects :)
What is the non-drug approach to reducing HTN?
reduce Na+ intake, weight loss, exercise, and eliminate smoking, caffeine, and stress.
What do the baroreceptors do when BP increases?
they stretch, sending afferent signal to the nucleus of the tractus solitarius in the brainstem, synapsing on inhibitory interneurons in the vasomotor center, inhibiting the sympathetics, and augmenting the parasympathetics.
What is the “Stepped Care” Method to treating HTN?
using drugs in combinations so that the compensatory mechanisms are neutralized and have an additive hypotensive effect.
What are the 3 steps in the Stepped Care method?
Step 1= diuretic, beta blocker or ACE inhibitor
Step 2= other sympathoplegic agents
Step 3= vasodilators
*What diuretics are preferred for mild to moderate HTN?
thiazides (ex. hydrochlorothiazide)
*What diuretics are preferred for severe HTN with significant renal impairment?
loop diuretics (ex. furosimide)
What is the CHRONIC effect of diuretics on HTN?
decreased peripheral resistance due to reduction in intracellular Na+ and Ca++, and thus less vasoconstricting action to NE/EPI and Ang II.