Adrenergic Agonists and Antagonists Flashcards
Epinephrine
direct acting agonist
- all receptors but A favored
- anaphylactic shock, acute asthma, cardiac arrest, anesthetics
Norepinephrine
direct acting agonist
- all receptors but A favored
- shock – b/c it increases vascular resistance and therefore increases BP.
Albuterol and Terbutaline
direct acting agonist
- B2
- chronic treatment of asthma, bronchitis, etc.
Clonidine
direct acting agonist
- A2
- lower BP, minimizes symptoms of withdrawal from opiates or benzodiazepams.
Dobutamine
direct acting agonist
- B1
- increase CO in congestive heart failure as well as for inotropic support after cardiac surgery.
Dopamine
direct acting agonist
- A1, B1, D1 and D2
- Treatment of shock (b/c alpha and beta blocking drugs have no effects on the dopaminergic receptors). Increases BP to increase CO (B1) and increases total peripheral resistance (A1)
Fenoldopam
direct acting agonist
- D1, A2
- Severe HTN
Isoproterenol
direct acting agonist
- B1 and B2
- stimulate heart in emergency situations
Metaproterenol
direct acting agonist
- B2
- asthma
Phenylephrine
direct acting agonist
- favors A1 over A2
- raises both systolic and diastolic BPs but induces bradycardia reflex when given parenterally. Can act as a nasal decongestant producing prolonged vasoconstriction.
Salmeterol and Formoterol
direct acting agonist
- B2
- nocturnal asthma (w/corticosteroid)
Oxymetazoline
direct acting agonist
- A1 and A2
- nasal spray decongestant and ophthalmic solutions for decrease in red eyes
Amphetamine
indirect acting agonist
- A and B
- ADHD – hyperactivity, narcolepsy and appetite control
Cocaine
indirect acting agonist
-block Na+ and K+ activated ATPase (required for cellular uptake of norepinephrine). Enhances sympathetic activity.
Tyramine
indirect acting agonist
-not clinically useful
Ephedrine
direct/indirect acting agonist
- A, B and CNS
- chronic asthma – to prevent attacks. Improves motor function in MG in conjunction w/ anticholinesterases inhibitors. Stimulates CNS alertness, decreases fatigue and prevents sleep. Improves athletic performance. Asthma as a nasal decongestant due to its local vasoconstrictor action. Raise BP
Pseudoephedrine
direct/indirect acting agonist
- A, B and CNS
- nasal and sinus congestion or congestion of the eustachian tube.
Phenoxybenzamine
antagonist - alpha blocker
A1 post synaptic and A2 presynaptic-irreversible and noncompetitive
-phenochromocytoma – a catecholamine-secreting tumor. Phenoxybenzamine initiates a hypertensive crisis before surgery which allows manipulation of the tissue. Can also be used for chronic management of these tumors.
-Raynaud’s disease.
Phentolamine
antagonist - alpha blocker
A1 and A2-competitive
-short term management of pheochromocytoma. Rarely used now for impotence
Prazosin,Terazosin and Doxazosin
antagonist - alpha blocker
A1-selective competitive
-HTN
Alfuzosin and Tamulosin
antagonist - alpha blocker
A1-selective competitive
-bengin prostatic hyperplasia
Yohimbine
antagonist- alpha blocker
A2-selective competitive
-sexual stimulant and Raynaud’s disease
Acebutolol, Atenolol, Metoprolol and Esmolol
antagonist - beta blocker
B1-selective
-HTN (good w/diabetic HTN pts who are receiving insulin)
Labetalol and Carvedilol
antagonist-beta blocker
A1, B1 and B2 - reversible
-HTN (elderly) and congestive heart failure. Labetalol treatment of pregnancy HTN and can be given IV in HTN emergencies.
Nebivolol
antagonist-beta blocker
B1, increase NO?
-HTN
Pindolol and Acebutolol
antagonist - beta blocker
B1, B2 and ISA
-HTN w/moderate bradycardia. Used in diabetic s w/HTN (b/c of carbohydrate metabolism is less affected w/these drugs)
Propanolol
antagonist-beta blocker
B1 and B2 - nonselective
-HTN, migraine, hyperthyroidism, angina pectoris, supraventricular cardiac arrhythmias and myocardial infarction
Timolol
antagonist - beta blocker
B1 and B2 - nonselective
-Glaucoma (open angle), HTN (occasionally)
Nadolol
antagonist - beta blocker
B1 and B2 - nonselective
-HTN
Reserpine
antagonist - affecting NT uptake/reuptake
-blocks the Mg2+/adenosine triphosphate-dependent transport of biogenic amines, norepinephrine, dopamine and serotonin from the cytoplasm into the storage vesicles in the adrenergic nerves of all body tissues. Sympathetic function is impaired b/c of decreased release of norepinephrine.
Guanethidine
antagonist - affecting NT uptake/reuptake
-blocks the release of stored norepinephrine and displaces norepinephrine from storage vesicles transient increase in BP.
Cocaine
antagonist - affecting NT uptake/reuptake
-blocks the reuptake of the monoamines into the pre-synaptic terminals.
