Adrenergic Pharmacology

Adrenergic Receptors

Receptor	Binding Affinity	Effects	Mechanism	Agonists	Antagonists
α1	NE > Epi >> Iso	Smooth muscle contraction	Gq, PLC -> IP3/DAG	NE Phenylephrine Midodrine	α1 selective: Prazosin Tamsulosin
α2	Epi = NE >> Iso	Mixed effects	Gi, presynaptic, cAMP down	Dexmedetomidine Clonidine	Non-selective: Phenoxybenzamine Phentolamine Trazodone
β1	Iso > NE > Epi	Chronotropy, Inotropy, Amylase secretion	Gs, cAMP up	Dobutamine Isoprenaline Norepi	Cardiac Selective: Metoprolol Atenolol Esmolol
β2	Iso > Epi > NE	Smooth muscle relaxation	Gs, cAMP up	Albuterol Formoterol Isoprenaline Salmeterol Terbutaline Ritodrine	Non-Selective: Propranolol Nadolol Pindolol Timolol Carvedilol (anti-α1) Labetalol (anti-α1)
β3	Iso > Epi = NE	Lipolysis, bladder detrusor relaxation	Gs, cAMP up	Mirabegron	SR 59230A