3: Muscle Relaxants Flashcards
primary goal
selective decrease skeletal muscle excitability
primary uses
1) muscle spasms
2) spasticity
injury usually to muscle or peipheral nerve
muscle spasm
tonic contraction in paraspinals, traps, etc.
muscle spasms
injury to CNS-- CNS lesions (SCI, CP, CVA, etc)
spasticity
exaggerated stretch reflex
spasticity
agents used to treat muscle spasms
1) centrally acting anti-spasm drugs
2) Diazepam (Valium)
muscle spasm agent: diverse group of drugs
centrally-acting antispasm drugs
muscle spasm agent: used commonly in back, neck spasms; other orthopedic injuries
centrally-acting antispasm drugs
centrally-acting antispasm drugs: enhances GABA inhibition in brain (GABA A effect)
Carisoprodol
centrally-acting antispasm drugs: might increase serotonin in brainstem
Cyclobenzaprine
all centrally-acting antispasm drugs are
strong sedatives
centrally-acting antispasm drugs primary effect
strong sedatives
antispasm drugs: short term use may be beneficial for…
acute muscle spasms
antispasm drugs: patients may decide to take only when? why?
bedtime bc it’s a strong sedative
antispasm drugs: should be combined with what?
aggressive physical therapy
antispasm drugs: when should drugs be decreased?
ASAP- discontinue drups (3-4 days) while continuing PT
muscle spasm agent: developed originally as an anti-anxiety drug
diazepam (valium)
Diazepam (Valium) is a ( ) agent
Benzodiazepine
How does Diazepam work in CNS?
increases inhibitory effects of GABA
Benzodiazepine receptors in phospholipid bilayer also have receptors for
GABA and barbituates
How does GABA cause inhibition?
Cl- channels open in protein and becomes more negative whice inhibits
Valium causes GABA to do what?
GABA binds stronger –> more Cl- enters –> more inhibition
Valium increases ( ) inhibition of the alpha motor neuron
GABA-mediated
spasticity agent: acts in CNS, increases GABA mediated inhibition
Diazepam