Adrenergic Drugs Flashcards
Prazosin (Minipress)
Alpha-1 Antagonist
Selective alpha-1 blocker
Primary use - antihypertensive
Very little alpha 2 activity means no reflex tachycardia
Induces vasodilation, decreases venous return
Also improves urinary flow
First dose phenomenon - CNS effects the first time its taken
Methoxamine
Alpha-1 Agonist
Not a substrate for COMT or MAO — very long half life
Primary use - vasoconstrictor
Clonidine
Alpha-2 Agonist
Primary use - Treat Hypertension
Central suppression of BP via action on alpha 2 receptors
Transient spike in BP, followed by prolonged hypotension
Reserpine
Sympatholytic Globally depletes catecholamines Inhibits amine and dopamine uptake, irreversible Further blocks NE storage and synthesis Extremely long acting (weeks)
Side Effects: significant CNS effects (depression, sedation, suicide)
Propanalol
Nonselective Beta-1 and Beta-2 antagonist
Primary uses - antihypertensive, heart disease (via decreasing HR)
At rest has little effect on a normal heart
Also treats glaucoma (via decreasing intraocular pressure)
Can reduce peripheral symptoms of hyperthyroidism
Side Effects: bronchoconstriction due to beta 2 antagonist action. Should not be used in patients with underlying lung disease
Also can cause profound hypoglycemia in diabetics
Membrane stabilizing effect, reduces membrane excitability
Phentolamine
Alpha Antagonist Nonselective competitive alpha blocker Primary use - pheochromocytoma Poor antihypertensive because it induces reflex tachycardia Also used in erectile dysfunction
Side Effects: orthostatic hypotension, reflex cardiac stimulation, nasal congestion
Phenylephrine
Alpha-1 Agonist Not a substrate for COMT — long half life Primary use - VASOCONSTRICTOR Treat hypotension Nasal decongestant
Phenoxybenzamine
Alpha Antagonist
Covalent, irreversible nonselective alpha blocker
May take days to recover alpha activity
Primary Use - treatment of PHEOCHROMOCYTOMA
Also used in benign prostate hypertrophy
Side Effects: orthostatic hypotension, nasal congestion, ejaculatory dysfunction
Ephedrine
Mixed Acting Adrenergic Agonist
Indirectly induces NE release, direct alpha/beta agonist
Primary Use - bronchodilation (mostly displaced by beta 2 selectives), urinary incontinence (promotes retention), appetite suppression
Cocaine
Prevents uptake from removing NE from the synaptic cleft, prolonging signaling
Terbutaline/Albuterol
Beta-2 Agonist
Not a substrate for COMT or MAO — very long half life
Primary use - BRONCHODILATOR
Better than non-selective beta agonists because they do not cause cardiac stimulation, unless you use too often
Inhibit mast cell secretion
Inhalation limits side effects
Methyl Tyrosine
NE Synthesis Inhibitor
Inhibits tyrosine hydroxylase, resulting in global catecholamine decrease
Blocks tyrosine —> L-DOPA conversion
Primary use - pheochromocytoma
Given pre-operatively to reduce risks when excising pheos
Side effects: sympathetic depression
Metroprolol
Cardioselective Beta-1 blocker
Primary uses - antihypertensive, ischemic heart disease (via decreasing HR)
At rest has little effect on a normal heart
Does not cause bronchoconstriction
Beta-2 Agonists
Bronchodilators
Alpha-1 Agonists
Vasoconstrictor
Treat hypotension, stimulate mydriasis, rhinitis (used as a decongestant)
Dobutamine
Beta-1 Agonist Primary use - INOTROPE Treat Congestive Heart Failure, increase cardiac contractility Also promotes vasodilation Side effects - tolerance may develop
Beta-3 Agonists
Treat urinary urgency or overactive bladder
Amphetamine (Vyvanse, Adderal)
Indirect Adrenergic Agonist
Enhances NE release and acts as a powerful CNS stimulant
Primary use - SCHEDULE I, but reduces fatigue, increases alertness, improves physical performance
Side Effects: appetite suppression, dependency, tolerance
Beta-1 Agonists
Vasodilator, treat congestive heart failure
Stimulate cardiac contractility
Dilates renal vasculature
Metraminol
Mixed Acting Adrenergic Agonist
Indirectly replaces NE in storage granules, direct alpha 1 agonist
Primary use - treat hypotension
Methyldopa
NE Synthesis Inhibitor
False neurotransmitter, displaces NE and binds with much lower affinity
Converted to alpha methyl norepinephrine in the body
Primary use - antihypertensive, probably via action on central alpha 2 receptors (similar to clonidine)
Side effects: CNS effects including sedation, drowsiness
Also sympathetic depression (orthostatic hypotension, nasal congestion, etc)
Alpha-2 Agonists
Vasodilator
Anti-hypertensive, treat hypertensive crisis
Guanethidine
Sympatholytic
Displaces NE from storage vesicles and exposes them to degradation by MAO. Also interferes with vesicle release
Primary use - strong antihypertensive. Vasodilator
Good oral availability with long half life
Side Effects: orthostatic hypotension, GI upset & diarrhea, male sexual disturbance
