Cardio Pharm: Autonomic Drugs Flashcards
Epinephrine selectivity
a1 agonista2 agonist B1 agonistB2 agonist(Mixed alpha beta receptor agonist)
Epinephrine uses
1: drug of choice for anaphylactic shock 2: prolong duration of local anesthetic
Describe how epinephrine acts in anaphylactic shock
1: Supports BP (increased vasoconstriction -a1, decreased fluid loss and edma- a1, increased cardiac output- increased HR and contractility- B1)2: Supports breathing (bronchial smooth muscle relaxation - B2, decreased mucous secretion- a1, decreased pulmonary edema- a1) 3: inhibit release of mediators of anaphylaxis (B2)
Norepinephrine selectivity
a1 a2 B1 (mixed alpha beta agonist)
Norepinephrine
a1- vascular resistance B1- increased cardiac contractility(both work together to increase bp)
Norepinephrine uses
1: Cardiogenic shock 2: Septic shock
Side effects of mixed alpha beta agonists
Extension of pharmacological effects 1: Tachy (B1) 2: Arrhythmia (B1) 3: Hypertensive crisis (a1) 4: Dry mouth, mild depression, sedation (a2) 5: Closed angle glaucoma
Name the a1 selective agonists
Phenylephrine**Methoxamine Midodrine
a1 selective agonist MOA
vasoconstriction
a1 selective agonist uses
1: Reduce Bleeding 2: Hypotensive crisis 3: Nasal decongestion
a2 selective agonists
MethyldopaClonidine
Methyldopa MOA
prodrug (can be used in hypertension during pregnancy) acts ONLY on the CNS to increase sympathetic outflow and lower blood pressure
Clondine MOA
works on both the CNS (lower sympathetic outflow) and PNS (lower NE release)
Uses of a2 selective agonists
Hypertension
Methyldopa side effects
Positive direct coombs & Hemolytic anemia lupus erythematosus
B1 selective agonists
DobutamineDopamine
Dobutamine uses
Failed cardiac pump function - Severe Congestive heart failure - Cardiogenic shock
Dobutamine MOA
increase cardiac output and contractility
Dopamine low dose
activation of D1 on kidneys resulting in increases diuresis
Domamine intermediate dose
Activation of B1 in the heart to increase contractile force
Dopamine high dose
acts on A1 receptors to increase peripheral resistance resulting in increase in HR
Dopamine uses
1: Septic Shock 2: Severe Congestive heart failure 3: Cardiogenic shock
Nonselective Beta receptor agonist
Isoproterenol
Isoproterenol uses
AV block (speed up conductance) Bradycardia Strokes-Adams attack (loss of cardiac output)
Dopamine 1 agonist
Fenoldopam
Fenoldopam uses
Hypertensive crisis (especially in those in renal failure)
Fenoldopam MOA
bind DA1 receptors on coronary and renal artery to cause vessel relaxation
Fenoldopam side effects
reflex tachycardia (due to stimulation of baroreflex)
Fenoldopam contraindication
Glaucoma (open or closed angle) - increases intraoccular pressure
Mixed alpha beta antagonists
Labetalol Carvediol
Latetalol uses
1: Hypertension 2: Hypertensive crisis3: Ischemic heart disease
Labetalol MOA
Competitive and reversibel binding to a1, B1, and B2 higher potency for BETA receptors
Carvedilol MOA
Competive and reversible binding to a1, B1, and B2 higher potency for BETA receptors
Carvediol uses
Hypertension Ischemic heart disease Chronic heart failure (preferred drug)(other: antioxidant, antiproliferative, NO production)
Mixed alpha beta antagonist Adverse effects
Bradycardia Precipitation of acute heart failureBronchospasmCold extremities Raynauds diseaseCNS- mental depression, insomnia, fatigue
Metabolic effects of mixed alpha beta antagonists
decreased blood glucose plasma levels altered plasma lipid levels (worsened profile)
Contraindications of Beta receptor antagonists
Asthma (nonselective should be avoilded) AV block (can worsen condition)
Nonselective alpha antagonists
Phenoxybenzamine Phentolamine
Phenoxybenzamine uses
Pheochromocytoma
Phenoxybenzamine MOA
competitive IRREVERSIBLE vasodialation Cardiac stimulation
Phenoxybenzamine AE
reflex tachycardia
Phenoxybenxamine Drug- drug interactions
High doses can block seratonin, histamine, and AcH
Phentolamine uses
1: reversal of anesthesia 2: Hypertensive crisis associated with MOA inhibitor
Phentolamine MOA
competitive REVERSIBLE, dose dependent Vasodilation Cardiac stimulation
Alpha 1 selective antagonist
Prazosin
Prazosin pharmacological effects
reduce LDL and TG and increase HDL suppress release of NE Dilate arteries and veins (decrease BP)
Prazosin clinical uses
Pheochromocytoma Chronic hypertension with benighn prostatic hyperplasia (BPH) Urinary retention in men with BPHChronic hypertension (not commonly used)
Prazosin adverse effects
First dose syncope (30-90 minutes after first dose) hypotension, dizziness, fainting, reflex tachycardia Nasal stuffiness, impotence, polyuria, water retention
nonselective beta antagonist
Propranolol
Propranolol uses
Infantile hemangioma hypertension ischemic heart disease Arrhythmia (Supraventricular and ventricular) Chronic heart failure
Beta antagonist MOA (selective and non-selective)
decrease cardiac output (target SA and AV nodes to slow rate and O2 requirements of the heart)
Beta antagonist AE (selective and non-selective)
Bradycardia
Beta antagonist discontinuation (selective and non-selective)
requires tapering
Beta antagonist drug-drug interaction (selective and non-selective)
insulin
Beta antagonist contraindication (selective and non-selective)
Asthma and AV block
