Common Receptors, Substrates and Drugs (Study Tip Gal)

Muscarinic Receptor Endogenous Substrate

Acetylcholine

Muscarinic Receptor Agonism and Drug Examples

Increased SLUDD

Pilocarpine, bethanechol

Muscarinic Receptor Antagonism and Drug Examples

Decreased SLUDD

Atropine, oxybutynin

Nicotinic Receptor Endogenous Substrate

Acetylcholine

Nicotinic Receptor Agonism and Drug Examples

Increased HR, BP

Nicotine

Nicotinic Receptor Antagonism and Drug Examples

Neuromuscular blockade

Neuromuscular blockers (e.g. Rocuronium)

Alpha-1 (mainly peripheral) Endogenous Substrate

Epi, NE

Alpha 1 (peripheral) Agonism and Drug Examples

Smooth muscle vasoconstriction, increased BP

Phenylephrine, dopamine (dose-dependent)

Alpha 1 (peripheral) Antagonism and Drug Examples

Smooth muscle vasodilation, decreased BP

Alpha 1 blockers (doxazosin, carvedilol, phentolamine)

Alpha 2 (central) Endogenous Substrate

Epi, NE

Alpha 2 (central) Agonism and Drug Examples

Decreased release of Epi and NE, Decreased BP and HR

Clonidine brimonidine (ophthalmic)

Alpha 2 (central) Antagonism and Drug Examples

Increased BP and HR

Ergot Alkaloids, yohimbine

Beta 1 Endogenous Substrate (heart)

Epi, NE

Beta 1 (heart) agonism and Drug Examples

Increased contractility, CO, HR

Dobutamine, isoproterenol, dopamine (dose-dependent)

Beta 1 (heart) antagonism and Drug Examples

Decreased CO and HR

B1 Selective blockers (metoprolol) and non-selective BBs (propranolol, carvedilol)

Beta 2 (lungs) Endogenous Substrate

Epinephrine

Beta 2 (lungs) Agonism and Drug Examples

Bronchodilation

Albuterol, terbutaline, isoproterenol

Beta 2 (lungs) Antagonism and Drug Examples

Bronchoconstriction

Non-selective BBs (propranolol, carvedilol)

Dopamine Endogenous Substrate

Dopamine

Dopamine Agonism and Drug Examples

Many, including renal, cardiac and CNS effects

Levodopa, pramipexole

Dopamine Antagonism and Drug Examples

Many, including renal, cardiac, and CNS Effects

First gen Antipsychotics (e.g. haloperidol), metoclopramide

Serotonin Endogenous Substrate

Serotonin

Serotonin Agonism and Drug Examples

Many, including platelet, GI, and psychiatric efffects

Triptans (e.g. sumatriptan)

Serotonin Antagonism and Drug Examples

Many, including platelet, GI, and psych effects

Ondansetron, second generation antipsychotics (e.g. quetiapine)

Isoproterenol

Mixed B1 and B2 Agonist

- used for bradycardia

- causes bronchodilation, increased heart rate

Carvedilol

A1, B1, B2 antagonist

- Decrease BP (d/t peripheral vasodilation and decrease in HR)

- Bronchoconstriction

Vasopressors

NE, Epi

A1, B1 agonist

- Increase HR, BP, vasoconstriction

Clonidine

Centrally acting A2 agonist

- Decreases overall sympathetic output (NE and Epi)

- Decrease BP and HR