drugs and the vasculature Flashcards
what is vascular tone
state of partial constriction, displayed by arterioles
define hypertension
above 140/90
danger of hypertension
most important risk factor for stroke (50% strokes), 25% of HF cases
overall treatment for hypertension including difference
first line- Acei/ARB if less than 55, CCB/thiazide diuretic is older than 55/afro carribean second line for BOTH- ACEi with CCB or ACEi with thiazide third line- all 3 step 4 aka resistant hypertension- spironolactone or alpha/beta blocker
RAAS system- what kidney detects, and effects of ACE
kidney detects increased SNS/ less perfusion pressure/less Na+ reabsorption vasoconstriction, salt/water retention and aldosterone (thus directly sodium uptake via kidney AND aldosterone)
what ACEi and ARB do
inhibit AT1 receptor or ACE, thus less ANG1 to 2
how ACEi reduces hypertension and heart failure
less TPR, less VENOUS RETURN (ie heart needs to work less harder as afterload less, also less fluid retention, so less preload too)
rule for ACE inhibitors
any drug ending in PRIL
DIAGRAM side effects of ACEi and ARB’s
generally well tolerated- hypotension (can feel dizzy) ONLY ACEi- cough (less breakdown of bradykinin) hyperkalaemia- less sodium uptake into blood, so more K+ stays in blood renal failure patients with renal artery stenosis- Ang 11 increases pressure in glomerulus= good GFR: these patients already have bad GFR, so less Ang11= even worse GFR
how CCB’s work
depolarisation opens VGCC, and Ca2+ enters and binds to calmodulin to form a complex, which activatates myosin light chain kinase (MLCK), which causes VCSM
types of CCB’s
dihydropyridines better for hypetension (AMLOPIDINE), rather than non-DHP’s ie verampamil
which drug to use for hypertension under 55
all has similar BP control- ACEi/ARB’s 1st line as their ADHERENCE is best due to least side effects
which drug to use for hypertension over 55/afrocarribean
if older, BP more due to atherosclerosis, so renin system has less effect ie more desensitised when older, thus CCB’s/ thiazide diuretic first line
which drug for HF/stroke patients- comparison of RAAS, CCB’s, diuretics and beta blockers
RAAS inhibitor better for HF, but CCB’s better for stroke patients however, diuretics better for HF/stroke compared to RAS beta blockers have lower all cause mortality, CV events and stroke
alpha blockers
less vasoconstriction= less TPR
