Adrenergic Agonists (Sympathomimetics)
The autonomic nervous system (ANS) works to keep the body’s homeostasis against internal
and external changes in the environment which alter the body’s internal functions (e.g., blood
pressure regulation, urinary excretion, water balance, and digestive functions).
Adrenergic agonists are autonomic nervous system drugs that stimulate the adrenergic
receptors of the sympathetic nervous system (SNS), either directly (by reacting with receptor
sites) or indirectly (by increasing norepinephrine levels). An adrenergic agonist is also called a
sympathomimetic because it stimulates the effects of SNS.
Adrenergic agonists are further classified into three: alpha- and beta-adrenergic agonists,
alpha-specific adrenergic agonists, and beta-specific adrenergic agonists.
Adrenergic Agonists: Generic and Brand
Names
Here is a table of commonly encountered adrenergic agonists, their generic names, and brand
names:
Classification Generic Name Brand Name
Alpha- and Beta- Adrenergic Drugs dobutamine Dobutrex
dopamine Intropin
ephedrine (generic)
epinephrine Adrenalin, Sus-Phrine
norepinephrine Levophed
,Alpha-Specific Adrenergic Agonists clonidine Catapres
phenylephrine Neo-Synephrine
Beta-Specific Adrenergic Agonists albuterol Proventil, Ventolin
arformoterol Brovana
isoproterenol Isuprel
levalbuterol Xopenex
metaproterenol Alupent
pirbuterol Maxair Autohaler
salmetrol Serevent Diskus
terbutaline Brethine
Disease Spotlight: Glaucoma, Shock, and
Asthma
● These agents are commonly used for treatment of glaucoma, asthma, and shock or
shock-like conditions.
● Glaucoma is an eye condition characterized by an increase in intraocular pressure.
Alpha adrenergic agonists help dilate the pupils, decrease the secretion of aqueous
, humor, and increase the uveoscleral outflow. These mechanisms relieve the eyes of
too much pressure.
● Shock is a complication most commonly caused by acute blood loss that can
significantly alter the functions of the organs and tissues. The effects of these agents
to the cardiovascular system include pressure increase, vasoconstriction, and
increased blood flow to the muscles.
● Asthma is a hypersensitivity reaction to specific triggers characterized by
inflammatory reactions and bronchospasm. Beta agonists are usually used for
treatment of bronchospasm and other obstructive respiratory conditions.
Alpha- and Beta-Adrenergic Agonists
● Alpha- and beta- agonists are drugs that are generally sympathomimetic. These
agonists stimulate all of the adrenergic receptors so they affect both alpha- and
beta-receptors.
● Popular examples of drugs under this class include dopamine, dobutamine, and
epinephrine.
Therapeutic Action
The desired and beneficial actions of alpha- and beta-agonists are as follows:
● Acting on the adrenergic receptors of the target organs, (i.e., increased heart rate
and myocardial contractility with the heart, bronchodilation with lungs, decrease
intraocular pressure with eyes).
● Other effects include: sweating, pupil dilation, increase in rate and depth of
respirations
● Facilitating the breakdown of glucose stores (glycogenolysis) so it can be used as
energy.
Indications
Alpha- and beta-agonists are indicated for the following medical conditions:
● Sympathomimetic of choice for shock is dopamine, a naturally occurring
catecholamine. Aside from stimulating the heart to increase the rate and force of its
contractions, it also causes dilation of the renal and splanchnic arterioles increasing
blood flow to the kidneys. This way, renal shutdown is prevented.
The autonomic nervous system (ANS) works to keep the body’s homeostasis against internal
and external changes in the environment which alter the body’s internal functions (e.g., blood
pressure regulation, urinary excretion, water balance, and digestive functions).
Adrenergic agonists are autonomic nervous system drugs that stimulate the adrenergic
receptors of the sympathetic nervous system (SNS), either directly (by reacting with receptor
sites) or indirectly (by increasing norepinephrine levels). An adrenergic agonist is also called a
sympathomimetic because it stimulates the effects of SNS.
Adrenergic agonists are further classified into three: alpha- and beta-adrenergic agonists,
alpha-specific adrenergic agonists, and beta-specific adrenergic agonists.
Adrenergic Agonists: Generic and Brand
Names
Here is a table of commonly encountered adrenergic agonists, their generic names, and brand
names:
Classification Generic Name Brand Name
Alpha- and Beta- Adrenergic Drugs dobutamine Dobutrex
dopamine Intropin
ephedrine (generic)
epinephrine Adrenalin, Sus-Phrine
norepinephrine Levophed
,Alpha-Specific Adrenergic Agonists clonidine Catapres
phenylephrine Neo-Synephrine
Beta-Specific Adrenergic Agonists albuterol Proventil, Ventolin
arformoterol Brovana
isoproterenol Isuprel
levalbuterol Xopenex
metaproterenol Alupent
pirbuterol Maxair Autohaler
salmetrol Serevent Diskus
terbutaline Brethine
Disease Spotlight: Glaucoma, Shock, and
Asthma
● These agents are commonly used for treatment of glaucoma, asthma, and shock or
shock-like conditions.
● Glaucoma is an eye condition characterized by an increase in intraocular pressure.
Alpha adrenergic agonists help dilate the pupils, decrease the secretion of aqueous
, humor, and increase the uveoscleral outflow. These mechanisms relieve the eyes of
too much pressure.
● Shock is a complication most commonly caused by acute blood loss that can
significantly alter the functions of the organs and tissues. The effects of these agents
to the cardiovascular system include pressure increase, vasoconstriction, and
increased blood flow to the muscles.
● Asthma is a hypersensitivity reaction to specific triggers characterized by
inflammatory reactions and bronchospasm. Beta agonists are usually used for
treatment of bronchospasm and other obstructive respiratory conditions.
Alpha- and Beta-Adrenergic Agonists
● Alpha- and beta- agonists are drugs that are generally sympathomimetic. These
agonists stimulate all of the adrenergic receptors so they affect both alpha- and
beta-receptors.
● Popular examples of drugs under this class include dopamine, dobutamine, and
epinephrine.
Therapeutic Action
The desired and beneficial actions of alpha- and beta-agonists are as follows:
● Acting on the adrenergic receptors of the target organs, (i.e., increased heart rate
and myocardial contractility with the heart, bronchodilation with lungs, decrease
intraocular pressure with eyes).
● Other effects include: sweating, pupil dilation, increase in rate and depth of
respirations
● Facilitating the breakdown of glucose stores (glycogenolysis) so it can be used as
energy.
Indications
Alpha- and beta-agonists are indicated for the following medical conditions:
● Sympathomimetic of choice for shock is dopamine, a naturally occurring
catecholamine. Aside from stimulating the heart to increase the rate and force of its
contractions, it also causes dilation of the renal and splanchnic arterioles increasing
blood flow to the kidneys. This way, renal shutdown is prevented.
