Section 3: Drugs that affect the nervous system Flashcards
Which nervous system consists of cranial and spinal nerves and all their branches (those nerves outside the CNS).
The Peripheral Nervous System (Pg. 297)
Which nervous system controls functions that are under conscious, voluntary control such as skeletal muscles and sensory neurons of the skin?
Somatic Nervous System (Pg. 297)
Which nervous system is comprised mostly of motor nerves, controls functions of involuntary smooth muscles, cardiac muscles, and glands?
The Autonomic Nervous System (Pg. 297)
One of the four types of nerve fibers:
Convey impulses from the internal organs to the CNS
Visceral afferent (sensory) fibers. (Pg. 297)
One of the four types of nerve fibers:
Convey impulses from the CNS to the internal organs, glands, and the smooth and cardiac (involuntary) muscles
Visceral efferent (motor) fibers. (Pg. 297)
One of the four types of nerve fibers:
Convey impulses from the head, body wall, and extremities to the CNS
Somatic afferent (sensory) fibers (Pg. 297)
One of the four types of nerve fibers:
Convey impulses from the CNS to the striated (voluntary) muscles
Somatic efferent (motor) fibers (Pg. 297)
What is the neurotransmitter in the sympathetic and parasympathetic division for the preganglionic fiber?
Acetylcholine (Pg. 299)
True or False:
All preganglionic neurons of the autonomic division and all postganglionic neurons of the sympathetic division are cholinergic
False.
All preganglionic neurons of the autonomic division and all postganglionic neurons of the parasympathetic division are cholinergic (Pg. 299)
What are two types of cholinergic (parasympathetic) receptors? And what are the onset / duration of each?
Nicotinic receptors: fast onset / short duration
Muscarinic receptors: slow onset / long duration
(Pg. 299 NOTE)
What are the two major receptor types for the adrenergic (sympathetic) nervous system?
Alpha-adrenergic receptors
Beta-adrenergic receptors
(Pg. 299)
Any one of the postulated adrenergic components of receptor tissues that responds to norepinephrine and to various blocking agents
alpha-adrenergic receptor
Any of the postulated adrenergic components of receptor tissues that respond to epinephrine and to various blocking agents
Beta-adrenergic receptor
Norepinephrine has more affinity for alpha or beta receptors?
Alpha (Pg. 299)
Epinephrine has more affinity for alpha or beta receptors?
Both! (Trick question) - nearly equal (Pg. 299-300)
Autonomic drugs can be classified into four groups:
Remember: these drugs mimic or block the effects of sympathetic and parasympathetic
- Cholinergic (parasympathomimetic) drugs
- Cholinergic blocking (parasympatholytic) drugs
- Adrenergic (sympathomimetic) drugs
- Adrenergic blocking (sympatholytic) drugs
(Pg. 301)
Drugs that affect nicotinic or cholinergic receptor sites on autonomic ganglia are:
Ganglionic-stimulating drugs and ganglionic-blocking drugs (Pg. 301)
Cholinergic drugs have little therapeutic value. For the most part, they are not thought of as emergency drugs. Which drug may be used to manage extreme cases of poisoning resulting from atropine-type drugs?
Physostigmine (Antilirium)
What is the best known cholinergic blocking drug used in emergency care?
atropine (Pg. 302)
What are the three naturally occurring catecholamines in the body?
Epinephrine, norepinephrine, dopamine
epinephrine (Adrenalin), norepinephrine (Levophed), dopamine (Intropin), and dobutamine (Dobutrex) are examples of what kind of drugs?
Direct-acting / synthetic catecholamines (Pg. 303)
True or False:
Catecholamines depend on their ability to act directly with alpha and beta receptors
True (Pg. 303)
Alpha 1 or Alpha 2?
Located on presynaptic and postsynaptic nerve endings.
Presynaptic receptors inhibit the further release of norepinephrine. Postsynaptic receptors produce vasoconstriction to increase resistance in blood vessels and thus increase blood prsssure
Alpha 2 (Pg. 303)
Alpha 1 or Alpha 2?
Located on the effector organs
Chief role is to stimulate contraction of smooth muscle. In the vasculature, this results in an increase of blood pressure.
Alpha 1 (Pg. 303)
Memory aid to differentiate the physiological effects of beta receptors:
1 heart (beta1) and two lungs (beta2) (Pg. 303 NOTE)
Beta receptors do what?
Stimulate the heart, dilate bronchioles, dilate blood vessels in the skeletal muscle, brain, and heart; and aid in glycogenolysis (Pg. 303)
Alpha activities in human beings:
- Vasoconstriction of arterioles, resulting in a rise in blood pressure and peripheral shunting of blood to the heart and brain
- Pupil dilation
- Relaxation of the gut
(Pg. 303)
Beta activities in human beings:
- Cardiac acceleration and increases contractility
- Vasodilation of arterioles supplying the skeletal muscle
- Bronchial relaxation
- Uterine relaxation
(Pg. 303)
Adrenergic blocking agents (alpha- and beta-blocking drugs)
Block the vasoconstricting effect of catecholamines. Used in certain cases of hypertension. (Pg. 303)
Why should all drugs with alpha effects be administered through a secure IV line?
Because of the possibility of extravasation (leakage of fluid) and tissue necrosis (Pg. 303 NOTE)
Examples of selective beta1-blocking agents
metoprolol (Lopressor, Toprol-XL) and atenolol (Tenormin) (Pg. 303)
Antihypertensive and antidysrhythmics
Examples of nonselective beta-blocking agents
antianginal antihypertensives: nadolol (Congard) and propranolol (Inderal)
antihypertensive: labetalol (Normodyne, Trandate).
(Pg. 303)
Examples of Opiod analgesics:
morphine, codeine (methylmorphine), hydromorphone (Dilaudid), meperidine (Demerol), fentanyl, methadone, oxycodone, hydrocodone, propoxyphene (Pg. 305)
Body’s own supply of “opiates”. Produced by the pituitary gland and the hypothalamus during strenuous exercise, excitement, pain, and orgasm. Act as “natural pain relievers”.
Endorphins (Pg. 305 NOTE)
Examples of Opiod antagonists:
Naloxone (Narcan), naltrexone (Trexan), nalmefene (Revex) (Pg. 305)
What makes the difference between Narcotic analgesics and Nonnarcotic analgesics?
When nonnarcotic analgesics are used, the nerve endings in damaged tissues are stimulated less often. This differs from the mechanism of narcotic analgesics that act at the level of the CNS. (Pg. 305)
What does NSAID stand for? And what are some examples?
nonsteroidal antiinflammatory drug
ketorolac (Toradol), tramadol (Ultram), ibuprofen (Advil), naproxen (Aleve), and acetaminophen (Tylenol)
(Pg. 305)
What is the name of drug that depresses the CNS? What are the three major types?
Anesthetics
General anesthesia: achieved by IV or inhalation- most common for surgery
Regional anesthesia: Injection near a nerve trunk (spinal block)
Local anesthesia: topically or injection to produce a loss of sensation (Lidocaine)
(Pg. 305)
A small dose of an agent administered to calm a patient is called a _____; a larger dose of the same agent sufficient to induce sleep is called a _____.
Sedative, hypnotic (Pg. 306)
Antianxiety and sedative-hypnotic agents and alcohol, depress what system that is known to determine the level of awareness to the environment?
reticular activating system (Pg. 306)
What two drugs are used to treat anxiety and induce sleep?
benzodiazepines (most often used today) and barbiturates. (Pg. 307)
What are benzodiazepines four actions? And why is it considered to be a schedule IV drug?
Anxiety reducing, sedative-hypnotic, muscle relaxing, and anticonvulsant
Schedule IV because of its potential for abuse (Pg. 307)
Examples of benzodiazepines:
alprazolam (Xanax), flurazapam (Dalmane), midazolam (Versed), lorazepam (Ativan)
(Pg. 307)
Barbiturates are divided into four classes according to their duration of action:
Ultrashort acting (seconds), short acting (10-15 mins), intermediate acting (45-60 mins), and long acting (more than 60 mins)
Dependent on their lipid solubility and protein-binding properties
(Pg. 307)
Which of the four classes of barbiturates is used to treat epilepsy and other chronic neurological disorders?
Long-acting barbiturates (Pg. 307)
Anorexiants and amphetamines are an example of:
CNS stimulants (Pg. 308)
What CNS stimulant stimulates the cerebral cortex and reticular activating system?
Amphetamines - increases alertness and responsiveness to environmental surroundings. (Pg. 308)
A potentially irreversible neurological disorder characterized by involuntary repetitious movements of the muscles of the face, limbs, and trunk
Tardive dyskinesia - excessive blinking, lip smacking etc. (Pg. 309)
This is often times caused by the use of certain antipsychotics, developing supersensitivity of dopamine receptors.
A condition characterized by local or diffuse changes in muscle tone, resulting in painful muscle spasms, unusually fixed postures, and strange movement patterns
Dystonia (Pg. 309)
Type of depression that is considered normal. Results from a person’s response to a loss or disappointment having “the blues”.
Exogenous depression (Pg. 309 NOTE)
Type of depression that lasts 6 months or longer. Characterized by the absence of external causes; maybe the result of genetic or biochemical alterations. Antidepressants often are needed to treat.
Endogenous depression (Pg. 309 NOTE)
What are two movement disorders resulting from an imbalance of dopamine and acetylcholine?
Parkinson’s disease and Huntington’s disease (Pg. 310)
What is the current drug of choice in the treatment of movement disorders associated with dopamine-acetylcholine imbalance?
Levodopa (L-dopa) (Pg. 311)
What drug is the preferred treatment for mania?
Lithium (an antimanic drug) (Pg. 309)
What do monoamine oxidase A and monoamine oxidase B metabolize?
MAO A- metabolizes norepinephrine and serotonin
MAO B- metabolizes dopamine
(Pg. 311)
Skeletal muscle relaxants can be classified as?
Central-acting muscle relaxants
Direct-acting muscle relaxants
Neuromuscular blockers
(Pg. 311)
Which muscle relaxant is used to treat muscle spasms, that are thought to work by producing CNS depression in the brain and spinal cord?
Central-Acting Muscle Relaxant - diazepam (Pg. 311)
Which muscle relaxant directly affect skeletal muscles to produce muscle relaxation, resulting in a decrease in muscle contraction?
Direct-Acting Muscle Relaxant - Dantrolene (Dantrium). (Pg. 311)
Which kind of muscle relaxant drug produces complete muscle relaxation and paralysis? It is accomplished by binding to the nicotinic receptor for acetylcholine at the neuromuscular junction.
Neuromuscular blockers - pancuronium, vecuronium, succinylcholine. (Pg. 311)
What are the two types of neuromuscular blocking drugs? And provide an example of each.
Depolarizing agent - succinylcholine - rapid onset, brief duration. Used commonly for ET intubation
Nondepolarizing agent - pancuronium - long onset, long duration
(Pg. 311 NOTE)
