ANS pharmacology & pathophysiology 5 Flashcards
Direct-acting vasodilators exert
an arterial relaxing effect without interfering with systemic or local constrictor mechanisms or Ca2+ channels
The primary action of nitroglycerin is
venodilator with reduced preload
The primary action of nitroprusside is
reduces afterload and preload
The primary action of hydralazine is
arterial smooth muscle dilator
The vasodilatory effect of NTG is greater on
venules than arterioles
Nitroglycerin exerts its action via the
liberation of nitric oxide, a vascular dilator
Nitroglycerin improves the balance of
myocardial O2 supply and demand due to its direct coronary artery vasodilator and systemic effects
____________ is an excellent first-line treatment of cardiac ischemia
Nitroglycerin
Cautioned should be used when using nitroglycerin in the setting of
a patient with myocardial ischemia who is hypovolemic–> risk of severe hypotension
when using nitric oxide liberation drug like sildenafil d/t risk of severe hypotension
Unlike nitroglycerin, nitroprusside is NOT used in _____
MI b/c it will induce “coronary steal”
Sodium nitroprusside is an ultra-short-acting
nitric oxide donor with potent venous and arteriolar vasodilator activity decreasing preload and afterload
____________ may be seen more so with sodium nitroprusside than nitroglycerine.
reflex tachycardia
_____________ is produced in sodium nitroprusside metabolism inhibiting aerobic metabolism
Cyanide
Cyanide also binds with hemoglobin forming
methemoglobin and binding to sulfur to form thiocyanate
The direct vasodilating activity of hydralazine is a result of
activation of KATP channels reducing intracellular Ca2+
____________ can be seen with hydralazine
Reflex tachycardia
Hydralazine preserves ___________ as it does not dilate
LV preload; venous capacitance vessels
Minoxidil’s strong, direct vasodilating effect is limited by
reflex-mediated tachycardia, necessitating co-administration of a beta antagonist
Use of minoxidil is uncommon due to
causing hypertrichosis (hair growth), salt and water retention, and rare reports of pericardial effusion
Phosphodiesterase 5 inhibitors include
sildenafil
tadalafil
vardenafil
PDE5 inhibitors work by
increasing levels of cGMP and targeting the lungs and penis (viagra)
induce smooth muscle relaxation and increase blood flow
PDE4 inhibitors include
roflumilast
apremilast
ibudilast
PDE4 inhibitors work by
increasing levels of cAMP, targeting the airways, skin, and immune system
PDE4 inhibitors are used for
airway smooth muscle relaxation in those with hyperreactive airways
useful in inflammatory states that affect the skin, bowel, and joints
PDE3 inhibitors include
milrinone and cilostazol
PDE3 inhibitors work by
increasing the levels of cAMP and cGMP and are used in those with CV disease
Uses of PDE3 inhibitors include
prevent platelet aggregation for thrombosis prophylaxis
promote vasodilation in peripheral vessels to treat intermittent claudication
increased inotropy and relaxation of vascular and airway smooth muscle
________ is a positive inotrope and is frequently used in weaning the patient from cardiopulmonary bypass.
Milrinone
Vasopressin acts on
V1, V2 and V3 cellular receptors
What is the function of V1 receptors?
mediate CV effects such as increased SVR
What is the function of V2 receptors?
function in the kidney as an antidiuretic hormone
What is the function of V3 receptors?
found in the pituitary gland and modulate autocoids
Vasopressin is indicated for those in
vasodilatory shock states who are resistant or refractory to catecholamine fluid therapy
The dry cough associated with an ACE-inhibitor is MOST likely due to:
a. paradoxical effect of drug-induced pulmonary vasoconstriction
b. accumulation of bradykinin
c. direct irritant effects of the ACE-inhibitor
d. dysregulation of catecholamines in the lung
b. accumulation of bradykinin
The ___________ is essential in cardiovascular homeostasis.
renin-angiotensin-aldosterone system (RAAS)
Lidocaine is a ______________
Class 1B antiarrhythmic
Class 1B antiarrhythmics suppress automaticity by
increasing the electrical stimulation threshold of the ventricle and His-Purkinje system & inhibiting spontaneous depolarization during diastole
ARBs have a greater affinity for the
AT1 receptor, impeding angiotensin 2’s effect at the AT1 receptor
ACE inhibitors imapir the activity of
both AT1 and AT2 receptors
Side effects of ARBs are
similar to ACEi but are milder and without the dry cough
ARBs are indicated for the treatment of
HTN, CHF, and coronary disease
ACE-inhibitors are best suited for
hypertension d/t increased renin production and are first-line therapy for HTN, CHF, mitral regurgitation, and LV dysfunction
ACE inhibitors decreasethe
generation of angiotensin, reduce arterial tone, and reduce left ventricular afterload
ACE inhibitors exert __________ in diabetic patients
renal protective effects
Important side effects of ACE-inhibitors include
dry cough d/t blockade of ACE-induced degradation of bradykinin
angioedema d/t inhibition of bradykinin breakdown
profound hypotension with GA
