3-Vasodilators Flashcards
Primary autonomic mechanism for blood pressure homeostasis; involves sensory input from carotid sinus and aorta to the vasomotor center and output via the parasympathetic and sympathetic motor nerves
Baroreceptor reflex
Vascular damage in heart, kidney, retina or brain
End-organ damage
Hypertension of unknown etiology; primary hypertension
Essential hypertension
An accelerated form of severe hypertension associated with rising blood pressure and rapidly progressing damage to vessels and end organs. Often signaled by renal damage, encephalopathy, and retinal hemorrhages or by angina, stroke, or myocardial infarction
Hypertensive emergency/malignant hypertension
Hypotension on assuming upright posture; postural hypotension
Orthostatic hypotension
Elevated BP resulting from loss of antihypertensive drug effect
Rebound hypertension
Tachycardia resulting from lowering of BP; mediated by the baroreceptor reflex
Reflex tachycardia
Hypertension caused by a diagnosable abnormality (exp. aortic coarctation, renal artery stenosis, adrenal tumor,)
Secondary hypertension
Drug that reduces effects of the SNS
Sympatholytic, Sympathoplegic
Chest discomfort caused by insufficient cardiac blood flow resulting in cardiac ischemia
Angina
Drugs that decrease peripheral vascular resistance or cardiac output
Vasodilators
Blockade of calcium channels, release of nitric oxide, opening of K+ channels (hyperpolarization), activation of D1 receptors
Mechanisms of vasodilators
Verapamil, Amlodipine, Clevidipine, Felodipine, Isradipine, Nisoldipine, Nicardipine, Nifedipine, Diltiazem
Calcium channel blockers
MOA of Verapamil, Diltiazem, Nifedipine
Reduction of calcium influx
Primary hyperaldosteronism
Conn’s Syndrome
Hypertensive urgency with end-organ damage
Hypertensive Emergency
Severely elevated BP with no evidence of end-organ damage
Hypertensive Urgency
Excessive hair growth
Hypertrichosis
Catecholamine-secreting tumor of the adrenal gland
Pheochromocytoma
A rare syndrome of encephalitis and hepatic dysfunction seen in children recovering from a viral illness linked to aspirin
Reye’s Syndrome
Repeated administration of medication leads to decreased effectiveness
Tolerance
T/F: Calcium combines with calmodulin to convert myosin light-chain kinase to its active form
True
What does active form of MLCK (MLCK*) do?
Phosphorylates myosin light chains, initiating interaction of myosin with actin
What other proteins inhibit ATPase activity of myosin during relaxation of smooth muscle?
Calponin & Caldesmon
Where are Type L channels (Cav1.1-Cav1.4) found?
Cardiac, skeletal, & smooth muscle, neurons, endocrine cells, bone
Verapamil, DHPs, Cd2+, omega 3-A block this type of Ca2+ channel?
L type
What is the MOA of CCBs?
Bind to L type Ca2+ channels & block inward movement of Ca2+, causing vasodilation
Where do CCBs bind?
L-type Ca2+ channels in heart & smooth muscle of coronary & peripheral vasculature
What are contraindications & indications for CCBs?
Contraindications: Bradycardia, HF
Indications: Hypertension, angina, arrhythmias
Peripheral edema, nausea, & flushing are adverse effects for what?
CCBs
Amlodipine, Felodipine, Isradipine, Nicardpine
Dihydropyridine (DHP) CCBs
Nifedipine is the prototype for?
DHP CCBs
What is the MOA of Non-DHP CCBs?
Decrease HR & Contractility; more cardioselective
Verapamil, Diltiazem
Non-DHP CCBs
Constipation is a common adverse effect for what drug?
Verapamil
Constipation, Vertigo, Headache, Fatigue, & Hypotension are common adverse effects for what kind of drugs?
CCBs
MOA for Nitroprusside, Hydrolazine, Nitrates, Histamine & Acetylcholine?
Release of nitric oxide from drug or endothelium
MOA for Minoxidil & Diazoxide?
Hyperpolarization of cell membranes through opening of potassium channels
MOA for Fenoldopam?
Activation of dopamine receptors
Nitroglycerin, Isosorbide mononitrate, & Isosorbide dinitrate are what kind of nitrates?
Oral
Nitroprusside is what kind of nitrate?
Parenteral
What are indirect acting organic nitrates and what enzyme do they require to release NO?
Nitroglycerin, Isosorbide mononitrate, & Isosorbide dinitrate
Enzyme: Aldehyde dehydrogenase
MOA of Nitrates?
Conversion to NO -> NO increases cGMP -> smooth muscle relaxation
-at higher conc’s, nitrates decrease afterload
Most commonly used antianginal agent & drug of choice for relieving acute coronary spasm
Nitroglycerin
How is Nitroglycerin administered?
Sublingually (for rapid onset), can be transdermal for longer duration of action
Orally active nitrate with relatively long half-life
Isosorbide dinitrate
Given by continuous IV infusion, rapidly metabolized to cyanide
Nitroprusside
Used for hypertensive emergencies
Nitroprusside
Throbbing headache & postural hypotension are adverse effects for this type of drug?
Nitrates
