13,14 Antihypertensives Flashcards
KATP opener drugs w/selectivity for cardiac cells
adenosine
sulfonylureas
mechanism? use?
inhibit Katp channel opening, allowing an increase in insulin
used for T2DM and single-gene defects causeing hypoinsulinemia
what drugs interrupt ischemic pre/post conditioning
sulfonylureas - close Katps
methylxanthines(caffeine, theophylline) - adenosine receptor antagonists
avoid these in CABGs
minoxidil
mechanism? use?
katp channel opener
used for hypertension; promotes hair growth!
KATP opener drugs w/selectivity for vascular smooth muscle
diazoxide
adenosine
minoxidil
Katp channels are found where?
when do they open?
cardiac myocytes, smooth muscle, pancreatic beta cells, brain, kidney
open up when ATP is low; think cardiac myocytes that are ischemic and want to slow down pace of heart.
direct vasodilators
hydralazine
minoxidil
diazoxide
mechanism? use?
Katp channel opener
decreases insulin
used for hyperinsulinemia, hypoglycemia, sulfonylurea OD
KATP opener drugs w/selectivity for pancreatic beta cells
diazoxide
adverse effects of adenosine
bradycardia, exacerbation of asthma(bronchoconstriction)
how are adenosine and diazoxide cardioprotective?
open KATP on mitochondria, allowing permeability channels to close
reserpine
blocks VMAT on NE storage vesicles
inactivates NE releasers
upper doses make it a tranquilizer
lower doses used to be used to treat hypertension
central a2AR agonists
methyldopa
clonidine
methyldopa
“conversion to methylNE in brainstem; a2 agonist
1st line antihypertensive in pregos; (no reduction in placenta or kidney flow)
“
clonidine uses
opiate withdrawal
anesthetic adjunct
GH stimulant
lower IOP
no longer used as anti-HTN
adverse effects of central a2AR agonists
methyldopa, clonidine
drowsy
somnolence
xerostomia
withdrawal excess SNS outlfow
myo ischemia
metyrosine
mechanism, use
competitive inhibitor of tyrosine hydroxylase
used to manage CA-secreting tumors
calcium channel blockers
nifedipine
amlodipine
verapamil
diltiazem
dihydropyridines
nifedipine
amlodipine
CCBs; only affect VSM
CCBs w/vascular and cardiac effects
verapamil - more cardiac than diltiazem
diltiazem
frequency vs voltage dependent calcium channels
cardiac CCs are frequency dependent(non-DHPs)
VSM CCs are voltage dependent(DHPs)
DHP adverse effects
flushing
swollen ankles
nifedipine, amlodipine
non-DHP adverse effects
LV dysfunction
AV block
avoid combo w/BBs
constipation
verapamil, diltiazem
CCBs metabolism
CYP3A4 p450 enzyme
competitive substrates can potentiate effects
