CV Drugs- ACE Inhibitors, Calcium Channel Blockers, Vasodilators Flashcards
concerns with antihypertensives and anesthesia- interference with the sympathetic nervous system’s activity resulting in
orthostatic hypotension related to hypovolemia, position change, or decreased venous return (PPV)
concerns with antihypertensives and anesthesia- possible depletion of
norepinephrine stores- minimal response to indirect sympathomimetics
concerns with antihypertensives and anesthesia- exaggerated response to
direct sympathomimetics- due to no counter- balancing beta 2 activity
beta-blockers may improve
the outcome of patients with HTN
other than __, HTN medication should be continued even on the morning of surgery- fewer alteration in BP and HR, fewer arrhythmias
diuretics
antihypertensives drug classes
- beta-adrenergic blockers- negative chronotropic, inotropic
- combined alpha1 and beta-adrenergic blocker (labetolol)- negative inotropic, chronotropic, vasodilation; not as potent as beta-blockers or phentolamine
- alpha 1-adrenergic blocker (prazosin, phentolamine)- vasodilation
- centrally acting alpha 2-adrenergic agonist (clonidine, dex)- decrease sympathetic outflow
ACEi MOA
- inhibit the ACE in both the plasma and in the vascular endothelium
- block the conversion of angiotensin I to angiotensin II
- prevent the vasoconstriction from angiotensin II and the stimulation of the SNS
- decrease aldosterone-decreased Na and water retention (however, increased K)
ACEi advantage
minimal side effects compared to beta-blockers, diuretics
ACEi indications
- HTN (in diabetes)
- CHF
- mitral regurgitation (F, F, V)
- development of CHF (regression of LVH)
ACEi contraindications
patients with renal artery stenosis (their renal perfusion is highly dependent on angiotensin II)
ACEi benefit
minimal side effects
most common side effects
cough, upper respiratory congestion, rhinorrhea, allergic-like symptoms (potentiation of kinins and inhibition of breakdown of bradykinins)
ACEi angioedema
potentially life-threatening (epi 0.30-0.5 ml of 1:1,000 dilution)
ACEi hyperkalemia
due to decreased production of aldosterone (especially CHF with renal insufficiency)
ACEi angioedema may occur
unexpectedly after prolonged drug use
ACEi hereditary angioedema is due to
C1 esterase inhibitor deficiency
ACEi induced angioedema is due to
increased availability of bradykinin because bradykinin catabolism is blocked
how is angioedema treated?
- epi (catecholamines, antihistamines, and antifibrinolytics may be ineffective in acute episodes)
- tranexamic acid or aprotinin- inhibits plasmin activation
- Icatibant- a synthetic bradykinin receptor antagonist
- FFP- 2-4 units- to replace the deficient enzyme
ACEi- captopril (Capoten)- causes
decreased SVR- especially in renal
ACEi- captopril (Capoten)- __, __ not effected
CO, HR
ACEi- captopril (Capoten)- __ reduced
baroreceptor sensitivity (HR does not increase with decreased BP)
ACEi- captopril (Capoten)- may cause
hyperkalemia (related to blocking of aldosterone release)
ACEi- captopril (Capoten)- onset
15 min
ACEi- captopril (Capoten)- duration
6-10 hours
ACEi- enalapril (Vasotec)- dose PO
20 mg PO
ACEi- enalapril (Vasotec)- dose IV
0.625-1.25 mg
ACEi- enalapril (Vasotec)- onset
approx 1 hour
ACEi- enalapril (Vasotec)- duration
18-30 hours
ACEi- enalapril (Vasotec)- lacks
the rash and pruritus side effects of captopril; rarely angioedema of the face, lips, tongue, and glottis; watch for hypotension
losartan (Cozaar)- MOA
blocks the binding of angiotensin II to the receptors (type AT1- found in vascular smooth muscle) to prevent vasoconstriction and aldosterone release
losartan (Cozaar)- side effects
similar as ACEi
losartan (Cozaar)- risk of
stroke reduction 25% (compared to atenolol)
losartan (Cozaar)- dose
50mg
losartan (Cozaar)- may be combined with
thiazide diuretic or inhibitor of neprilysin (Entresto)
calcium channel blockers classifications
- phenylalkylamines
- 1,4-dihydropyridines
- benzothiazepines
CCB- phenylalkylamines
occludes the channel (verapamil)
CCB- 1,4-dihydropryridines
arterial vascular smooth cells (nifedipine, nicardipine, nimodipine)
CCB- benzothiazepines
AV node, MOA? (diltiazem)
CCB MOA
- bind to the alpha subunit of the slow L-type calcium ion channels
- block calcium entering the cardiac and vascular smooth muscle cells (arterial specific)
- reduction of calcium
CCB MOA of reduction of calcium
- fails to activate myosin- which reduces contraction
- slows depolarization of SA and AV nodal tissue
CCB effects- __ inotropic, chronotropic effects
negative
CCB effects- __ SA node activity
decreased
CCB effects- conduction slowed through the
AV node
CCB effects- vaso__, __ BP
dilation, decreased
CCB effects- relaxes
coronary artery spasm (complements nitrate- different MOA)
CCB uses
- treatment of coronary artery spasm
- unstable angina pectoris
- chronic stable angina
- essential hypertension
CCB increased risk with dihydrophyrimidine derivates (nifedipine)
- CV complications (placebo)
- perioperative bleeding, GI hemorrhage
- development of cancer (beta-blockers, ACE inhibitors)
CCB- verapamil (Calan)- is a derivative of
papaverine
CCB- verapamil (Calan)- effects
- decreases contractility
- decreased HR
- decreased conduction through AV node
- relaxation of vascular smooth muscle, coronary arteries
CCB- verapamil (Calan)- uses
treatment of SVT (AV node), HTN
CCB- verapamil (Calan)- dose
75-150mcg/kg (2.5-5mg) IV slowly
CCB- verapamil (Calan)- onset
1-3 minutes
CCB- verapamil (Calan)- oral nearly complete __ metabolism
hepatic
CCB- verapamil (Calan)- IV metabolism
70% renal and 15% bile
CCB- verapamil (Calan)- elimination 1.2 life
6-12 hours
CCB- verapamil (Calan)- combination with volatile anesthesia
has additive myocardial depressant and vasodilation effects, even in normal LV function
CCB- nifedipine (Adalat, Procardia)-
dihydropyridine
CCB- nifedipine (Adalat, Procardia)- vasodilation of
coronary and peripheral arteries (>verapamil)
CCB- nifedipine (Adalat, Procardia)- __ BP
decreases
CCB- nifedipine (Adalat, Procardia)- ___HR
indirect baroreceptor-mediated increased
CCB- nifedipine (Adalat, Procardia)- __ contractility, __ chronotropic, and __ effects
directly decreased
decreased
dromotropic
CCB- nifedipine (Adalat, Procardia)- admin
PO, IV, SL
CCB- nifedipine (Adalat, Procardia)- uses
- angina
- especially coronary artery vasospasm
- hypertension emergencies (CAUTION/STOP-cerebrovascular ischemia, MI, severe hypotension)
CCB- nifedipine (Adalat, Procardia)- dose
10-20 mg PO or SL
CCB- nifedipine (Adalat, Procardia)- onset
20 min
CCB- nifedipine (Adalat, Procardia)- metabolism
hepatic
CCB- nifedipine (Adalat, Procardia)- elimination 1/2 life
2-5 hours
CCB- nifedipine (Adalat, Procardia)- side effects
- flushing
- HA
- vertigo
- hypotension
- may cause renal dysfunction
CCB- nifedipine (Adalat, Procardia)- abrupt stop has causes
coronary artery vasospasm
CCB- nicardipine (Cardene)- __ vasodilation
selective arterial (SVR)
CCB- nicardipine (Cardene)- __ vasodilation effects
greatest (especially coronary arteries)
CCB- nicardipine (Cardene)- does not effect
the SA node of AV node, minimal myocardial depressant effects
CCB- nicardipine (Cardene)- dose
25 mg in 240 ml (0.1mg/ml)
titrate- start at 5mg/hr (50ml/hr), increase by 2.5 mg/hr every 5-15 mins to a max of 15 mg/hr
CCB- nicardipine (Cardene)- not compatible with
LR
CCB- clevidipine (Cleviprex)-
3rd generation dihydropyridine
CCB- clevidipine (Cleviprex)- onset
rapid, titratable
CCB- clevidipine (Cleviprex)- __ emulsion
lipid (similar to propofol)
CCB- clevidipine (Cleviprex)- metabolism
plasma and tissue esterases (organ independent)
CCB- nimodipine (Nimotop)- highly
lipid soluble to cross BBB
CCB- nimodipine (Nimotop)- used to treat
vasospasm related to subarachnoid hemorrhage
CCB- nimodipine (Nimotop)- dose
0.7 mg/kg PO then 0.35 mg/kg q4 hours for 21 days
CCB- nimodipine (Nimotop)- if intracranial compliance is a concern,
an increase in ICP could occur
CCB- diltiazem (Cardizem, Dilacor, Tiazac)-
benzothiazepine
CCB- diltiazem (Cardizem, Dilacor, Tiazac)- blocks
channels in the AV node
CCB- diltiazem (Cardizem, Dilacor, Tiazac)- uses
treatment of SVT, angian pectoris
CCB- diltiazem (Cardizem, Dilacor, Tiazac)- dose
0.25 mg/kg IV over 2 minutes, may repeat in 15 min if needed
infusion 10mg/hr
CCB- diltiazem (Cardizem, Dilacor, Tiazac)- elimination
via bile (60%) and urine (35%)
CCB- diltiazem (Cardizem, Dilacor, Tiazac)- elimination 1.2 time
3-5 hours
CCB drug interactions- volatile anesthetics
additive myocardial depression and vasodilation, especially with preexisting LV dysfunction
CCB drug interactions- depolarizing and nondepolarizing NMB drugs like mucin antibiotics
potentiated (Ca ions are needed to release acetylcholine at the NM junction)
CCB drug interactions- LA
increased risk of toxicity (inhibition of Na ion movement via Na channels)
CCB drug interactions- K replacement
hyperkalemia due to inhibition of K moving into cell
CCB drug interactions- __ and __ cause hyperkalemia
verapamil and dantrolene
CCB drug interactions- digoxin
increase in digoxin plasma concentration- decreasing its clearance
vasodilators- indications
- treat HTN
- induce controlled hypotension
- encourage LV SV
vasodilators- effects
- decrease BP
- decrease SVR (arterial)
- decrease venous return and CO (ventilator)
nitric oxide- nitrovasodilators cause
both pulmonary and systemic vasodilation be producing NO
nitric oxide- increases
intracellular cGMP causing smooth muscle relaxation (results ultimately from decreased intracellular calcium similar to the effect of cAMP from beta 2 stimulation)
nitric oxide- can be
inhaled in the gaseous state to cause pulmonary vasodilation specifically
nitric oxide- endogenous- CV effects: release of NO from endothelial cells due to
shear stress and pulsatile arterial flow
nitric oxide- endogenous- CV effects: regulation
SVR and PVR- baseline
nitric oxide- endogenous- CV effects: impacts
distribution of cardiac output
nitric oxide- endogenous- CV effects: autoregulation
increased NO production with decreased oxygenation
nitric oxide- endogenous- CV effects: __ produce more NO than __
arteries
veins
(IMA remains patent longer than saphenous vein grafts)
nitric oxide- endogenous- pulmonary effects:
- bronchodilation
- selective dilation of vessels to ventilated alveoli
nitric oxide- endogenous- platelet effects:
inhibits plt activation, aggregation, and adhesion (antithrombotic)
nitric oxide- endogenous- nervous system effects: NT in
brain, spinal cord, and peripheral nervous system
nitric oxide- endogenous- nervous system effects: may be involved in
antinociception and anesthetic effects
nitric oxide- endogenous- nervous sytem effects: produce
relaxation of smooth muscle of the Gi tract
nitric oxide- endogenous- immune response: produced in response to
activation of macrophages
nitric oxide- endogenous- immune response: can damage
bacteria, fungi, and protozoa
pathophysiologic effects related to NO- essential hypertension
decreased NO release
pathophysiologic effects related to NO- sepsis shock
excessive NO release
pathophysiologic effects related to NO- atherosclerosis
decreased NO, plt aggregation, vasoconstriction
pathophysiologic effects related to NO- cirrhosis
excessive production of NO
anesthetic effects on NO- involved in the
excitatory neurotransmission
anesthetic effects on NO- anesthetics cause suppression of
formation of NO to decrease excitatory NT and enhance GABA inhibitory transmission
anesthetic effects on NO- administration of NO synthase inhibits have __ in MAC
dose dependent reduction in
uses of NO
- inhaled form to treat PH (use in any other than neonates is “off label”)
- in neonates, its use has decreased the use of ECMO
sodium nitroprusside (SNP, nipride)- is a
direct-acting, arterial and venous vascular smooth muscle relaxant
sodium nitroprusside (SNP, nipride)- causes vasodilation of
arterial and venous
sodium nitroprusside (SNP, nipride)- onset
60-90 seconds
sodium nitroprusside (SNP, nipride)- duration
short requiring infusion, titration
sodium nitroprusside (SNP, nipride)- monitoring
careful, infusion device used
sodium nitroprusside (SNP, nipride)- dose
0.25-1 mcg/kg/min, up to 5 mcg/kg/min (body can handle only 2 mcg/kg/min continuous)
sodium nitroprusside (SNP, nipride)- MOA
reacts with hemoglobin to form methemoglobin and releases cyanide and NO; NO causes the vasodilation
sodium nitroprusside (SNP, nipride)- is __ cyanide and during metabolism __
44%
5 cyanide ions are release making cyanide toxicity possible0 causing tissue anoxia, anaerobic metabolism, and lactic acidosis
sodium nitroprusside (SNP, nipride)- susceptible to CN toxicity
- receiving infusion of > 2 mcg/kg/min
- children or young adults- baroreceptor reflexes cause stimulation of SNS, require larger dose
- pregnancy- fetal cyanide toxicity
sodium nitroprusside (SNP, nipride)- signs and symptoms of CN toxicity
- unresponsive to previously therapeutic doses of SNP
- increased MvO2- inability of tissues to use oxygen
- metabolic acidosis
- CNS dysfunction, seizures
sodium nitroprusside (SNP, nipride)- treatment of CN toxicity
- stop infusion
- 100% O2
- sodium bicarb to correct met acidosis
- sodium thiosulfate to be a sulfur donor to convert cyanide to thiocyanate
sodium nitroprusside (SNP, nipride)- must be protected from
the light to prevent breakdown into cyanide; light-protected solution are safe for 24 hours
sodium nitroprusside (SNP, nipride)- CV effects:
direct partial and venous vasodilation
sodium nitroprusside (SNP, nipride)- CV effects: __ BP, SVR
decreased
sodium nitroprusside (SNP, nipride)- CV effects: __ HR and contractility
indirect increase in
sodium nitroprusside (SNP, nipride)- CV effects: __ CO
may have increased
sodium nitroprusside (SNP, nipride)- CV effects: ___ vasodilation which creates __
coronary artery
coronary steal from ischemic areas
sodium nitroprusside (SNP, nipride)- CV effects: __ diastolic pressure
decrease
sodium nitroprusside (SNP, nipride)- CNS effects: __ CBF
increased
sodium nitroprusside (SNP, nipride)- CNS effects: __ CBV
increased
sodium nitroprusside (SNP, nipride)- CNS effects: if pt has decreased intracranial compline,
ICP may become dangerously elevated
sodium nitroprusside (SNP, nipride)- CNS effects: ICP increases are maximal if
MAP decreases less than 30%; if >30% decrease in MAP, the ICP returns to normal
sodium nitroprusside (SNP, nipride)- CNS effects: to prevent the increase in ICP,
infuse SNP to slowly lower BP over 5 minutes along with hyperopia and hypocarbia
sodium nitroprusside (SNP, nipride)- CNS effects: once the dura is open, ICP
problems are not a problem
sodium nitroprusside (SNP, nipride)- CNS effects: contraindications
patients with increased ICP and inadequate CBF, and patents with carotid artery stenosis
sodium nitroprusside (SNP, nipride)- pulmonary effects:
decrease in the PaO2
sodium nitroprusside (SNP, nipride)- pulmonary effects: alteration of
HPV
sodium nitroprusside (SNP, nipride)- pulmonary effects: bigger problem in
healthy lungs
sodium nitroprusside (SNP, nipride)- pulmonary effects: COPD lungs develop
vascular changes that prevent the alteration of HPV
sodium nitroprusside (SNP, nipride)- pulmonary effects: treatment of alteration in HPV
add PEEP
sodium nitroprusside (SNP, nipride)- inhibits
platelet aggregation (>3 mcg/kg/min); not clinically significant- bleeding not increased
sodium nitroprusside (SNP, nipride)- clinical uses:
- deliberate hypotension
- hypertensive emergencies
- cardiac disease
- aortic surgery
- cardiac surgery
sodium nitroprusside (SNP, nipride)- clinical uses: deliberate hypotension- mostly likely to
maintain cerebral perfusion
sodium nitroprusside (SNP, nipride)- clinical uses: deliberate hypotension- initial rate
0.3-0.5 mcg/kg/min
sodium nitroprusside (SNP, nipride)- clinical uses: deliberate hypotension- should not exceed
2 mcg/kg/min
sodium nitroprusside (SNP, nipride)- clinical uses: deliberate hypotension- combined with other agents to
minimize risk of CN toxicity
sodium nitroprusside (SNP, nipride)- clinical uses: HTN emergencies-
temporary initial treatment, effective no matter the cause, onset, tritration, quick offset
sodium nitroprusside (SNP, nipride)- clinical uses: cardiac disease-
decreased afterload (MR, AR, CHF, MI with LV failure but may also need inotrope)
sodium nitroprusside (SNP, nipride)- clinical uses: aortic surgery
treat HTN related to cross-clamp, spinal cord ischemia- distal hypotension
sodium nitroprusside (SNP, nipride)- clinical uses: cardiac surgery
- rewarming period to cause vasodilation to distribute warmth to periphery
- treat PH after valve replacement
nitroglycerin-
organic nitrate
nitroglycerin- dilates
venous side except, at elevated doses, it will relax arterial smooth muscle
nitroglycerin- MOA
produces NO which causes peripheral vasodilation
nitroglycerin- sublingual onset
4 minutes
nitroglycerin- transdermal
sustained protection from MI
nitroglycerin- infusion requires
special tubing and glass bottles to prevent absorption into the plastic
nitroglycerin- elimination 1/2 life
1.5 minutes; requires infusion
nitroglycerin- may cause
the production of methgb when the nitrite metabolite oxidizes the ferrous ion in hgb
nitroglycerin- methgb treatment
methylene blue 1-2 mg/kg IV over 5 minutes to convert back to hgb
nitroglycerin- CV effect: __ dilation
venous (up to 2mcg/kg/min)
nitroglycerin- CV effect: __ venous return, LVEDP, RVEDP
decreased
nitroglycerin- CV effect: CO __
decreased (in normal heart with no CHF; if patient in heart filature, the CO is improved, and pulmonary congestion is relieved)
nitroglycerin- CV effect: _ BP
decreased (related more to volume than SNP)
nitroglycerin- CV effect: __ DBP, coronary blood flow
decreased
nitroglycerin- CV effect: __ tachycardia, __ inotropic effect
baroreceptor-reflex
increased
(increased demand, decrease supply)
nitroglycerin- CV effect: dilates
larger conductance vessels of the coronary circulation- provides better blood flow to ischemic areas
nitroglycerin- CV effect: relaxes
pulmonary vessels
nitroglycerin- smooth muscle effect: relaxes
- bronchial smooth muscle
- biliary tract smooth muscle (sphincter of ddi)
- esophageal muscles
- uterine and ureteral smooth muscles
nitroglycerin- CNS effect:
- cerebral vasodilation
- inhibition of plt aggregation
nitroglycerin- clinical uses:
- angina pectoris
- cardiac failure
- acute HTN
- deliberate hypotension
nitroglycerin- clinical uses: angina pectoris
decrease myocardial oxygen demand and vasodilator coronaries to ischemic areas (decrease size of MI-not SNP)
nitroglycerin- clinical uses: cardiac failure
decrease preload and relieve pulmonary edema
nitroglycerin- clinical uses: acute HTN
maternal pt during C-section with no effects on fetus
nitroglycerin- clinical uses: deliberate hypotension
less potent than SNP; decrease in diastolic is less than SNP; intravascular volume has a bigger effect
isosorbide dinitrate-
oral nitrate- prophylaxis of angina pectoris
isosorbide dinitrate- prolonged __ effect, increased __
antianginal
exercise tolerance up to 6 hours
isosorbide dinitrate- vasodilation of
venous circulation and dilation of coronary arteries to redirect blood flow to ischemic areas
isosorbide dinitrate- given to
CABG patients preop
hydralazine (Apresoline)- direct dilation
arterial side, some venous
hydralazine (Apresoline)- vasodilates
coronary, cerebral, renal, and splanchnic, pulmonary vessels
hydralazine (Apresoline)- MOA
interferences with Ca ion transport
hydralazine (Apresoline)- decreases
diastolic more than systolic pressure
hydralazine (Apresoline)- increases
HR (baroreceptor and direct), SV, CO (can cause MI, prevented with beta-blocker)
hydralazine (Apresoline)- onset
10-20 minutes (prolonged)
hydralazine (Apresoline)- duration
2-4 hours (unpredictable)
hydralazine (Apresoline)- dose
10-20 mg
hydralazine (Apresoline)- metabolism
mostly hepatic
hydralazine (Apresoline)- side effects
- lupus-like syndrome
- peripheral neuropahties
- vertigo
- diaphoresis
- nausea
- tachycardia
uncommon in intermittent use
trimethaphan- is an
ganglionic blocker0 blocks autonomic nervous system reflexes
trimethaphan- vasodilation of
venous capacitance vessels
trimethaphan- __ CO, SVR
decreases
trimethaphan- blocks
receptors for ACh
trimethaphan- may have __ that offsets the benefit of __
tachycardia
decreased BP
trimethaphan- historical use
deliberate hypotension
adenosine- is an
endogenous nucleoside in all cells- maintain the balance of O2 supply and demand of the heart and other organs
adenosine- effects
dilation of coronary arteries (steal possible); negative chronotropic
adenosine- MOA
stimulation of K channels in supra ventricular cells to hyper polarize atrial cells and slowing of SA node (can also stimulate release of NO from endothelial cells)
adenosine- uses
- SVT
- deliberate hypotension
adenosine- uses: SVT for
paroxysmal SVT and narrow complex tachycardia (not atrial fib or v tach)
adenosine- for SVT dose
6 mg IV then 12 mg then 18 mg
adenosine- for SVT can repeat dose within
60 seconds
adenosine- for SVT elimination 1/2 life
0.6-1.5 seconds
adenosine- uses: deliberate hypotension because of
rapid responsiveness, onset and recovery
adenosine- for deliberate hypotension: __ SVR, __ HR, __ coronary flow, __ cardiac filling pressures
decreased
increased (reflex tachycardia)
increased
unchanged
adenosine- for deliberate hypotension: dose
220 mcg/kg/min- no tachyphylaxis
principle adenosine effects- adenosine 1 receptor effect
- slowing of the rhythm neg inotropic effects
- vasoconstriction
- bronchoconstriction
- sedation anticonvulsant effect; decrease of NT release
principle adenosine effects- adenosine 2 receptor effect
- vasodilation
- bronchodilation
- complex stimulant effects
- increase of NT release
- plt aggregation inhibition