Drugs Flashcards
NS B blockade: eg, indications
- eg: propranolol, nadolol, timolol
- indications: angina, HTN, arrhythmias
- phasing out for more specific drugs, lipophilic -> CNS defects
B1 blockade: eg, effects, indication,
- eg: MEAN B.
- effects: decrease HR, contractility, AV conduction velocity, renin release
- indication: CV indications; post MI, essential HTN
- esmolol: short acting IV only
- note* B2 in high doses
Vasodilation B blockade
- eg: carvadelol, lebatelol VERY COMMONLY used
- MOA: a/B blockade
> vasodilation A1 mediated - Nebivilol B1 selective (increased NO -> vasodilation)
B-blockers adverse effects (B1 and B2)
- B1: bradycardia, hypotension, worsening of acute HF
- B2: bronchospasm, masking of hypoglycemia, hyperglycemia, PVD exacerbation, impotency
- CNS: fatigue, depression, decreased exercise tolerance
B-blockade contraindications (3) consideration(2)
- abrupt cessation
- risk of unopposed activation
- severe bradycardia or AV block
- cardiogenic shock or worsening HF
- varian angina
A-antagonist specific agents (a1 and NS a1,2)
A1 a,b and d specific eg: terazosin, doxazosin, prazosin (reversible a 1a,b and d)
- BPH
eg: NS a1,2 antagonists: - phentolamine, phenoxybenzamine
A1 antagonism Sx/Cind
Sx - orthostatic HTN - reflex tachy - nasal congestion Cind - elderly (falls) - additive hypotension with other hypotensives - start low titrate up - less effect at bed time
A2 specific agonists (eg, ind)
Clonadine
- ind: hypertensive emergency/urgency and intractable HTN
Methyldopa
- ind: prodrug for HTN in pregnancy
A2 agonism Sx and considerations
Adverse effects
- CNS sedation and depression
- hypotension, bradycardia, orthostasis, rebound HTN
- GI, drymouth
- Methyldopa: hepatitis, hemolytic anemia
- as always avoid in elderly and abrupt discontinuation
Pressors and inotropes (eg and use)
pressors: maintain perfusion in hypotensive PTs.
- epi:
- norepi:
- phenylepi: a1 only
- dopamine (also inotropic)
- dobutamine (inotropic only)
Pressors and inotropes Sx (4)
- tachycardia
- dysrhythmia
- peripheral ischemia
- hypotension (dobutamine)
Atropine: CV pharmacology
- MOA: M2 blockade
- CV indication: acute symptomatic bradycardia (not for cardiac arrest)
- Sx: anti ACh
Epinephrine MOA (low/high dose)
- low dose: B1, B2 > a1 agonism
- high dose: a1 > B1,B2 agonism
Isoproteronol
- B1, B2 agonism
Norepi MOA
- B1, a1
Phenylepherine MOA
- a1 agonism
a1, a2, B1, B2 receptor actions
- a1: vasoconstriction
- a2: decrease sympathetic outflow
- B1: increase HR
- B2: vasodilation
Chemical cardiac stress test
- dobutamine
Class I antidysrhythmic useful for pharm cardioversion of Afib and Aflutter
- 3 classic Sx
- quinidine
- risk of toursades
- Toursades, tinnitus, cinchonism
Trt for toursades
- Mg
- unknown mechanism
- also used for resistant VT/VF and Digoxin toxicity
Trt for dig toxicity
- Mg
- arrythmias caused by digoxin toxicity: phenytoin
Class I antidysrhythmic
- Na channel blockade
- quinidine, procainamide, dyspirimine
Class II antidysrhythmics
- beta blockade: reduces Ca influx during phase 0, (slow current channels) and decreases automaticity (phase 4) esp in SA/AV nodes
- reduces nodal reentry tachydysrhythmias; reduces AV node conduction velocity and increases ERP
- metoprolol, propranolol et al
- not or use in acute HF: better for prevention (doesn’t terminate)
Na/K pump inhibitor
In crease in intracellular Na -> increase calcium influx -> increase contractility
- positive inotrope/negative chronotrope, slows SA/AV conduction increase absolute refractory period
- Sx: GI, arrythmias, yellow halos (dig Abs)
First line drug for SVT
- adenosine
- cAMP mediated Ca influx -> inhibits AV/SA node; essentially restarts the heart by induction of 3rd degree block but it’s 1/2 life is 10 ~ sec
Cass IV antidysrhythmic used as first line foratrial dysrhythmias. It may cause HF, hypotension or AV block
Verapamil/Diltiazam
Class III antidysrhythmic convert atrial flutter conversion and Risk
- ibutalide: prolongs APD
- Sx: toursades de points
Class III antidysrhythmic used in atrial and atrioventricular dysrhythmias. Sx
- Sotalol: atrial and ventricular arrythmias
- B blocking: proarrhythmic
- prolongs QT interval
First line for venticular dysrhythmias, biphasic 10/53 day 1/2 life
- amniodarone
- class III K channel blocking; also, Na, Ca, and B blocking
- prolong QT interval
Class III antidysrhythmic
- bretylin
- Sotalol
- ibutalide
- amniodarone
Class Ib antidysrhythmic
- phenytoin/lidocaine: prolongs ERP but shortens APD
- for ventricular dysrhythmias
- CNS effects, liver damage, CHF
- CIND: elderly
- primarily effects diseased/ischemic myocardium **
Class Ia antidysrhythmic (3)
- Na channel blockade (phase 0 decrease slope) k channel (phase 4 increase)
- dysopyramide (ACh effects)
- procainamide (SLE)
- quinidine (Torsades)
SLE induction
- procainamide
- hydralazine
Drugs that are associated with increased survival in HF PTs. (5)
- ACEIs
- B-blockers (carvedilol, metoprolol, bisprolol)
- spironolactone
- ARBs
- hydralazine + nitrates
Steps in managing systolic HF with drugs
- Loop diuretic
- Add ACEIs
- Add B-blocker
- Add spironolactone (K sparing)
- Add digoxin
- Add ARB, hydralazine, nitrite
Diastolic HF management
- control HTN, HR and ischemic heart disease
- avoid inotropes
Recombinant natriuretic peptide used in acute decompensating HF to decrease pre and after load
- Nesiritide
Arteriolar vasodilator used in combo with other nitrates in PTs who cannot tolerate ACEis
Hydralazine
ARBs and ACEIs
- both inhibit the renin-angiotensin pathway
- ARBs don’t screw with bradykinin (less cough or edema)
- ACEis contra indicated in preggers - fetal injury
Drugs that decrease arteriolar vasoconstriction, ANP release and NaCl resorb
- inhibits bradykinin breakdown
- ACEis
- decrease afterload AND preload
Sx: cyanide poisoning
- Na Nitroprusside
- rare, more commonly hypotension is only Sx due to vasodilation MOA (NO)
- contraindicated in pregnancy
Drugs of acute decompensating HF
- NO
- Na Nitroprusside
- phosdi inhibitors (Milrinone)