• Direct Muscarinic Agonists

  • Choline Esters

  • Alkaloids

• Direct Nicotinic Agonist

• Acetylcholinesterase Inhibitor (Reversible)

• Acetylcholinesterase Inhibitor (Irreversible)

• Muscarinic Antagonist

• 2-PAM

• Ganglionic Blockers

• Catecholamines

• Direct Adrenoceptor Agonists

• Indirect-Acting Sympathomimetics

• Alpha adrenoceptor Antagonists

• Beta-adrenoceptor Antagonists

• Adrenergic Neuron Blocking Drugs

Choline Esters

• Acetylcholine

• Bethanechol (Urecholine)

• Carbachol

• Methacholine (Provocholine)

Alkaloids

• Muscarine

• Pilocarpine (Pilocar)

Nicotine

Acetylcholinesterase Inhibitors ("Reversible")

• Neostigmine (Prostigmin)

• Physostigmine (Antilirium)

• Edrophonium (Tensilon)

Acetylcholinesterase Inhibitors ("Irreversible")

• Soman

• Parathion

• Malathion

• Isoflurophate (Floropryl)

• (Diisopropylflurorphosphate DFP)

• Echothiophate (Phospholine)

• Atropine

• Scopolamine

• Ipratropium (Atrovent)

• Pirenzepine (M₁ selective)

• Pralidoxime (Protopam) {2-PAM}:peripheral acetylcholinesterase reactivator for certain phosphoryl-enzyme complexes

• Mecamylamine (Inversine)

• Hexamethonium

• Trimethaphan

DRUG

Epinephrine

Norepinephrine (Levophed)

Isoproterenol (Isuprel)

Dobutamine (Dobutrex)

Dopamine (Intropin)

Receptor Classification

alpha-1, alpha-2, beta-1, beta-2

alpha-1, alpha-2, beta-1

beta-1, beta-2

beta-1 (alpha-1)

D-1 (alpha-1 and beta-1 at high doses)

Drug

Phenylephrine (Neo-Synephrine)

Methoxamine (Vasoxyl)

Oxymetazoline (Afrin)

Clonidine (Catapres)

Ritodrine (Yutopar)

Terbutaline (Brethine)

Albuterol (Ventolin,Proventil)

Salmeterol (Serevent)

Receptor Classification

alpha-1

alpha-1

alpha-1, alpha-2

alpha-2

beta-2

beta-2

beta-2

beta-2

Drug

Ephedrine, Pseudoephedrine

Cocaine

Tyramine

Amphetamine

Mechanism of Action

Release & direct receptor activation

Uptake I inhibitor

Release

similar to ephedrine, but greater CNS actions

Drug

Prazosin (Minipress)

Terazosin (Hytrin)

Trimazosin

Doxazosin (Cardura)

Phentolamine (Regitine)

Phenoxybenzamine (Dibenzyline)

Tolazoline (Priscoline)

Labetalol (Trandate, Normodyne)

Yohimbine (Yocon)

Receptor Selectivity(alpha₁ vs. alpha₂)

alpha-1

alpha-1

alpha-1

alpha-1

non-selective

only slightly selective for alpha-1 (non-competitive)

non-selective

alpha-1 (also non-selective beta-antagonist)

alpha-2

Drug

Propranolol (Inderal)

Metoprolol (Lopressor)

Esmolol (Brevibloc)

Atenolol (Tenormin)

Nadolol (Corgard)

Timolol (Blocadren)

Pindolol (Visken)

Labetalol (Trandate, Normodyne)

Butoxamine

Receptor Selectivity

non-selective

beta-1

beta-1

beta-1

non-selective

non-selective

non-selective (partial agonist)

non-selective (selective alpha-1-antagonist)

beta-2 (no clinical applications)

Reserpine

Guanethidine (Ismelin)

• non-selective blockade of vesicular uptake and storage of biogenic amines

• similar to reserpine: Uptake I dependent