Somatic NS + Drug Classifications

Question 1

somatic NS

Answer 1

voluntary
skeletal muscle contraction
neurons connect with skeletal muscle fibers at NMJ

Question 2

what NT acts on what receptors in somatic NS

Answer 2

ACH on nicotinic 2 receptors

Question 3

what does somatic NS control

Answer 3

respirations, contraction of diaphragm/chest muscles, tone for mvmt, posture

Question 4

drug categories and subcategories of somatic NS

Answer 4

1. peripheral skeletal muscle relaxants
   - depolarizing agents
   - non-depolarizing agents
   - direct acting agents
2. centrally acting skeletal muscle relaxants

Question 5

MOA of skeletal muscle relaxants in general

Answer 5

inhibit skeletal muscle contraction by interfering w neuromuscular function

Question 6

uses for skeletal muscle relaxants in general

Answer 6

painful injuries
decrease spasms from trauma/overexertion/tension
spastic diseases like cerebral palsy or M.S.
pre-op

Question 7

MOA of depolarizing agents (peripheral SMR)

Answer 7

binds to Nm receptor and induces depolarization causing muscle fasciculations
alters Nm receptor so it cannot respond to endogenous ACH and prevents contractions from occurring

Question 8

drugs of depolarizing agents

Answer 8

succinylcholine

Question 9

side effects of depolarizing agents (succinylcholine)

Answer 9

jaw rigidity, hypotension, arrhythmias
can be toxic if cholinesterase is abnormal
should only be used in emergent situations in ped pts

Question 10

MOA of non-depolarizing agents (peripheral SMR)

Answer 10

occupies Nm receptor sites, ACH cannot bind, no contraction or depolarization can occur

Question 11

drugs of non-depolarizing agents

Answer 11

rocuronium bromide (Zemuron®)

Question 12

antidote for rocuronium bromide (Zemuron®)

Answer 12

neostigmine (Prostigmin®) or sugammadex

Question 13

uses for non-depolarizing agents (rocuronium bromide (Zemuron®)

Answer 13

intubation, adjunct therapy for anesthesia, mechanical ventilation

Question 14

side effects for for non-depolarizing agents (rocuronium bromide (Zemuron®)

Answer 14

jaw rigidity, hypotension, arrhythmias, respiratory depression

Question 15

MOA for direct acting agents (peripheral SMR)

Answer 15

inhibits skeletal muscle contraction, blocks Ca++ release within muscle fiber

Question 16

drug examples of direct acting agent

Answer 16

dantrolene (Dantrium®)

Question 17

uses for direct acting agents (dantrolene (Dantrium®) )

Answer 17

spastic condition (cerebral palsy/M.S.), spinal cord injuries, malignant hyperthermia

Question 18

side effects for direct acting agents (dantrolene (Dantrium®) )

Answer 18

hepatotoxicity, vommiting, dizziness, fatigue, weakness

Question 19

contraindication for direct acting agents (dantrolene (Dantrium®) )

Answer 19

patients with lier disease

Question 20

MOA for centrally acting skeletal muscle relaxants

Answer 20

decreases number of impulses available to produce a contraction at motor neurons
block conduction within spinal cord

Question 21

drug examples for centrally acting skeletal muscle relaxants

Answer 21

• cyclobenzaprine (Flexeril®)
• carisoprodol (Soma®)
• methocarbamol (Robaxin ®)
• orphenadrine citrate (Norflex®)
• chlorzoxazone (Parafon Forte DSC®)
• metaxalone (Skelaxin®)

Question 22

uses for centrally acting SMR

Answer 22

spasms, injury, overexertion

Question 23

side effects of centrally acting SMR

Answer 23

blurred vision, fatigue, decreased mental alertness, dizziness, decreased muscle tone, hypotension
avoid alcohol and operating heavy machinery

Question 24

myasthenia gravis

Answer 24

autoimmune disease

antibodies attack Nm receptors

Question 25

symptoms of myasthenia gravis

Answer 25

skel musc weakness, paralysis, eyelids droop

Question 26

MOA of myasthenia gravis

Answer 26

increased ACH at all nicotinic receptors | decreased activity of acetylcholinesterase that breaks down ACH

Question 27

drugs of myasthenia gravis

Answer 27

- neostigmine (Prostigmin®) - pyridostigmine - ambenonium

Question 28

side effects of myasthenia gravis drugs

Answer 28

N/V/D, blurred vision, excessive sweating, muscular tremors, bronchoconstriction, bradycardia, hypotension (excessive parasympathetic activity)