chapter 21 and CLI quiz drugs Flashcards
what determines the adequacy of perfusion of the tissues of the body
vascular tone
when does ischemia occur
when decreased perfusion leads to an O2 deficit
when does hypoxia occur
when there is O2 deprivation despite adequate perfusion
what is the common treatment for angina pectoris
nitroglycerin
what effect does acetylcholine have when applied directly to de-endothelialized blood vessels
vasoconstriction
what effect does acetylcholine have when applied to normally endothelialized vessels
vasodilation
what is the main isoform involved with cardiovascular actions and is produced by endothelial cells
ET-1
what do ETa receptors on vascular smooth muscle cells mediate
vasoconstriction
what does ETb predominately mediate
vasodilation via release of prostacyclin and NO
what does activation of alpha1- adrenergic receptors on vascular smooth muscle cells cause
vasoconstriction
what does activation of beta2-adrenergic receptors on vascular smooth muscle cells induce
vasodilation
what is the equation for blood flow
perfusion pressure/resistance
what inhibitors prevent cGMP hydrolysis and thereby promote myosin light chain dephosphorylation, especially in smooth muscle of corpus calcium erosion
cGMP phosphodiesterase type 5 (PDE5) inhibitors
how do calcium channel blockers cause vasodilation
by reducing intracellular calcium concentration
what do hydrazine and beta-adrenergic antagonists modulate
vascular tone
how can excessive decrease in mean arterial pressure manifest
dizziness, lightheadedness, and occasionally overt syncome
what is the half life of NTG
40 minutes
what is the half life of isosorbide dinitrate
1 hour
what patients are nitrates contraindicated in
patients with hypotension and those with elevated intracranial pressure
what is PDE5 prescribed for
erectile dysfunction
what patients are PDE5 contraindicated in
those taking organic nitrate vasodilators
what do dihydropyridines bind to
N binding site
what do benzothiazepine bind to
D binding site
what does phenylalkylamines bind to
V binding site
where is nifedipine (dihydropyridine) excreted by
kidney
where is verapamil (phenylalkylamines) excreted by
kidney
where is diltiazem (benzothiazepine) excreted by
liver
where is bosentan a competitive inhibitor
at Eta and Ebb receptors
what is bosentan approved for use of treatment of
pulmonary hypertension
what is the major adverse effect of bosentan
elevation in serum transaminase levels
what odes hydrazine appear to prevent
development of nitrate tolerance
what does prazosin do
blocks alpha-adrenergic receptors
what is the principle use of terazosin
inhibits contraction of nonvascular smooth muscle
what is the mechanism of action of aspirin
inhibits platelet cycloxygenase, thereby blocking thromboxane A2, and inhibiting platelet granule release reaction and platelet aggregation
what is the mechanism of action of clopidogrel
covalently modify platelet ADP receptor, thereby preventing receptor signaling and irreversibly inhibiting ADP-dependent platelet activation pathway
what is the mechanism of action of unfractionated heparin
combines with antithrombin III and inhibits secondary hemostasis via non-selective inactivation of thrombin, factor Xa, IXa, XIa, and XIIa
what is the mechanism of action of LMW heparin
combine with antithrombin III and inhibit secondary hemostasis via relatively selective inactivation of factor Xa
what is the mechanism of action of t-PA
proteolytically activate plasminogen to form plasmin, which digests fibrin to fibrin degradation products
what is the mechanism of action of warfarin
inhibit hepatic epoxide reductase that catalyzes the regeneration of reduced vitamin K, which is required for synthesis of biologically active coagulation factors II, VII, IX and X and anticoagulant proteins C and S
