( Chapter 18 Adrenergic Drugs) Flashcards
1
Q
Adrenergic receptors
A
- Receptor sites located throughout the body for the sympathetic neurotransmitters norepinephrine and epinephrine (a and b receptors)
- Dopaminergic receptors respond only to dopamine
2
Q
a-adrenergic receptors
A
- A class of adrenergic receptors that is further subdivided into a1 and a2.
- Both types are differentiated by their anatomical location in the tissues, muscles, and organs regulated by specific autonomic nerve fibers.
- Agonist respone results in vasoconstriction and CNS stimulation
- Stimulation of these receptors on smooth muscle are vasoconstriction of blood vessels, relaxation of GI smooth muscles, contraction of the uterus and bladder, male ejaculation, decreased insulin release, and contraction of the ciliary muscles of the eye (dilated pupils)
- Adverse effects include headache, insomnia, tachycarida, palpitations, nausea, vomiting, etc
3
Q
Adrenergics
A
Drugs that stimulate the sympathetic nervous system; also referred to as adrenergic agonists or sympathomimetics because they mimic the effects of the sympathetic neurotransmitters norepinephrine and epinephrine, and dopamine
4
Q
B-adrenergic receptors
A
- Receptors located on the post synaptic effector cells of the cells’ tissues. muscles, and organs that are stimulated by specific autonomic nerve fibers
- This class is further divided into B1 (heart) and B2 (lungs)
- Agonist response results in bronchial, GI, and uterine smooth muscle relaxation, cardiac stimulation (increased HR)
- Adverse effects include headache, dizziness, increased HR, palpitations, sweating, nausea, vomiting, etc
5
Q
Catecholamines
A
Substances that can produce a sympathomimetic response. They are either endogenous (such as epinephrine, NE, or dopamine) or synthetic (such as dobutamine, phenylephrine).
- Binds directly to the receptor and causes a physiological response (direct acting)
- Indirect-acting causes the release of catecholamine from the storage sites (vesicles) in the nerve endings. The catecholamine then binds to the receptors and causes a physiological response.
- Mixed acting directly stimulates the receptor by binding to it and indirectly stimulates the receptor by causing the release of stored neurotransmitters from the vesicles in the nerve endings.
6
Q
Dopaminergic receptor
A
- A third type of adrenergic receptor located on various tissues and organs and activated by the binding of the neurotransmitter dopamine, which occurs in both endogenous and synthetic forms
- Causes dilation of the following blood vessels resulting in increased blood flow: renal, Mesenteric, coronary, cerebral
7
Q
A1 Adrenergic receptor
A
- Located on postsynaptic effector cells (the cell, muscle, or organ that the nerve stimulates)
- Constriction of blood vessels, GI sphincters, bladder sphincters, penis for ejaculation
- Nasal decongestants stimulant this receptor
8
Q
A2 Adrenergic receptor
A
- Located on presynaptic nerve terminals (the nerve that stimulates the effector cells.
- Control the release of neurotransmitters
9
Q
B1 recetors
A
- Stimulation of these receptors on the mycardium, Av node, and SA node results in cardiac stimulation: Increased force of contraction (positive inotropic effect)
Increased heart rate (positive chronotropic effect)
Increased conduction through the AV node (positive dromotropic effect)
10
Q
B2 receptors
A
Stimulation of these receptors on the airway result in: bronchodilation, uterine relaxation, glycogenolysis in the liver, and increased renin secretion in the kidneys
- Drugs end in “ol” or “ine”
11
Q
Bronchodilators
A
- Used in the treatment of asthma or bronchitis and stimulate B2 receptors of bronchial smooth muscles, causing relaxation, resulting in bronchodilation
- Monitor for therapeutic effects: Return to normal respiratory rate, improved breath sounds, fewer crackles, increased air exchange, decreased cough, less dyspnea, improved blood gases, and increased activity tolerance
