DƯỢC LÍ Goodman & Gilman's The Pharmacological Basis of Therapeutics 12th, 2010

Table 8–7
Representative Agents Acting at Peripheral Cholinergic and Adrenergic Neuroeffector Junctions
MECHANISM OF ACTION SYSTEM AGENTS EFFECT
1. Interference with synthesis Cholinergic Choline acetyl transferase Minimal depletion of ACh
of transmitter
inhibitors
Adrenergic α-Methyltyrosine (inhibition Depletion of NE
of tyrosine hydroxylase)
2. Metabolic transformation Adrenergic Methyldopa Displacement of NE by α-methyl-NE,
by same pathway as
which is an α 2
agonist, similar to
precursor of transmitter
clonidine, that reduces sympathetic outflow
from CNS.
3. Blockade of transport system Cholinergic Hemicholinium Block of choline uptake with
at nerve terminal membrane
consequent depletion of ACh
Adrenergic Cocaine, imipramine Accumulation of NE at receptors
4. Blockade of transport Cholinergic Vesamicol Block of ACh storage
system of storage vesicle Adrenergic Reserpine Destruction of NE by mitochondrial
MAO, and depletion from adrenergic
terminals
5. Promotion of exocytosis Cholinergic Latrotoxins Cholinomimetic followed by
or displacement of
anticholinergic
transmitter from Adrenergic Amphetamine, tyramine Sympathomimetic
storage sites
6. Prevention of release Cholinergic Botulinum toxin Anti-cholinergic
of transmitter Adrenergic Bretylium, guanadrel Anti-adrenergic
7. Mimicry of transmitter Cholinergic
at postjunctional sites Muscarinic a Methacholine, bethanachol Cholinomimetic
Nicotinic b Nicotine, epibatidine, cytisine Cholinomimetic
Adrenergic
α 1
Phenylephrine Selective α 1
agonist
α 2
Clonidine Sympathomimetic (periphery); reduced
sympathetic outflow (CNS)
α 1
,α 2
Oxymetazoline Non-selective α adrenomimetic
β 1
Dobutamine Selective cardiac stimulation
(also activates α 1
receptors)
β 2
Terbutaline, albuterol Selective β 2
receptor agonist
metaproterenol
(selective inhibition of smooth
muscle contraction)
β 1
,β 2
Isoproterenol Nonselective β agonist
8. Blockade of postsynaptic Cholinergic
receptor Muscarinic a Atropine Muscarinic blockade
Nicotinic d-tubucurarine, Neuromuscular blockade
(N m
) b atracurium
Nicotinic Trimethaphan Ganglionic blockade
(N n
) b
Adrenergic
α 1
,α 2
Phenoxybenzamine Nonselective α receptor blockade
(irreversible)
α 1
,α 2
Phentolamine Nonselective α receptor blockade
(reversible)
α 1
Prazosin, terazosin, Selective α 1
receptor blockade
doxasozin
(reversible)
(Continued)