Receptor Agonists & Antagonists
Alpha 1
Agonist Antagonist
Systemic vasoconstrictor Systemic vasodilator (decreases norepinephrine response)
Treats shock or low blood pressure Treats benign prostatic hypertrophy (BPH)
Example - Norepinephrine Example - Phentalomine
Alpha 2
Agonist Antagonist
Decreases sympathetic output from CNS - lowers blood pressure None
Treats hypertension  
Example - Clonidine  
Non-specific Beta 1&2
Agonist Antagonist
Beta 1 - Elevates heart rate, increases AV nodal conduction Beta 1 - Decreases heart rate, oxygen consumption, and lowers blood pressure
Beta 2 - Bronchodilator Beta 2 - Bronchoconstrictor
Beta 1 - Treats AV block and bradycardia Beta 1 - Treats hypertension, and reduce angina
Beta 2 - Treats asthma Beta 2 - Can cause asthma
Example - Isoproterinol Example - Propranolol
Cardioselective Beta 1 Blockers
Agonist Antagonist
None Decreases heart rate, and oxygen consumption
  Treats hypertension, and angina
  Example - Metoprolol, Atenolol
Pulmonary Selective Beta 2
Agonist Antagonist
Bronchodilator None
Treats asthma  
Example - Albuterol  
Agonist Antagonist
Increases contractions of smooth muscle, decreases heart rate, and increases secretions of exocrine glands Decreases GI activity, and secretions; increases heart rate and force
Treats GI stasis, and paroxysmal atrial tachycardia (PAT) Treats GI or GU spasms, dry secretions, and used for pre-op
Examples - Acetylcholine, Methacholine, Carbacholine, Uricholine Examples - Atropine, Scopolamine
Nicotinic (Ganglia)
Agonist Antagonist
None Decrease sympathetic tone to heart and blood vessels; decrease blood pressure dramatically
  Treats hypertensive crisis
  Example - Trimethoprim
Nicotinic (Skeletal muscle)
Agonist Antagonist
Inhibits acetylcholinase, and elevates acetylcholine at skeletal muscle sites Decrease skeletal muscle activity at neuro-muscular junction (blockers)
Treats myasthenia gravis and spasms; antagonist of the blockers (curare) Used for surgery, and mysthenia gravis diagnosis
Examples - Physostigmine, Neostigmine Example - Succinylcholine (Curare)
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