Adrenergic Agents

Adrenergic Agents

I Definition:
A. Drugs that stimulate the sympathetic nervous system. (SNS) (The automatic/autonomic nervous system)
B. AKA
1. adrenergic agonists
2. sympathomimetics: mimics the sympathetic nervous system
II Characteristics of adrenergic agents
A. Mimic the effects of the SNS neurotransmitters
1. norepinephrine (NE)
2. Epinephrine (EPI)
III Adrenergic Receptors
A. Located throughout the body
B. Are receptors for the sympathetic neurotransmitters
C. All fight or flight responses
D. Alpha
1. Alpha-adrenergic receptors respond to NE
2. Differentiated by their location on nerves
3. Predominant Alpha-Adrenergic agonist (with) Responses
a. Vasoconstriction
b. CNS stimulation (speed)
4. Alpha 1
a. constricts (when stimulated vessels constrict)
b. alpha 1 = blood vessels
c. mydriasis: eye dilation (constriction of muscle dilates eye)
d. located on postsynaptic effector cells (the cell, muscle, or organ that the nerve stimulated)
5. Alpha 2
a. located on presynaptic nerve terminals (the nerve that stimulates the effector cells...end of nerve, remember anatomy class)
b. control the release of neurotransmitters
E. Beta
1. All are located on postsynaptic effector (organ) cells
2. Beta-adrenergic receptors respond to EPI
3. Beta 1 : (1 heart) located primarily in the heart.
a. agonist response:
i. cardiac stimulation
4. Beta 2 : (2 lungs) located in smooth muscle of the bronchioles, arterioles, and visceral organs (visceral means organs doesn’t it?)
a. agonist response:
i. bronchial, GI, and uterine smooth muscle relaxation
ii. glycogenolysis: conversion of glycogen into glucose in the liver and muscles
F. Dopaminergic Receptors
1. An additional adrenergic receptor
2. stimulated by dopamine
3. causes dilation of the following blood vessels, resulting in increased blood flow: (when dopamine stimulates these, blood flow increases...normally when blood vessels are dilated, blood flow decreases.)
a. renal
b. mesenteric (mesentary: peritoneal fold that encircles the small intestine)
c. coronary
d. cerebral
IV Indications
A. Respiratory Indications
B. Indications for topical nasal decongestants
C. Ophthalmic Indications
D. Cardiovascular Indications
V Contraindications
A. The only usual contraindications of adrenergic drugs is known drug allergy and severe hypertension.
VI Adverse Effects
Etc:
A2 is the nerve controlling the release. It helps coach NE out of the nerve. A1, B1, and B2 are on the organ cells. See the chart. Action potential comes down and A2 releases NE...etc.

Questions asked in class:

Which of the following is true of Beta 1 stimulation?
a. primarily located in the heart
b. causes glycogenolysis in the liver
c. decreases heart rate

Which of the following are naturally occurring and can also be synthesized?
a. NE
b. EPI
c. dopamine