Pharmacology Muscle Relaxants Flashcards Preview

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Flashcards in Pharmacology Muscle Relaxants Deck (34):
1

What is the primary goal of muscle relaxers

Selectively decrease muscle excitability

2

What is meant by selectively decreasing excitability

Only decrease excitability of the muscles with too much excitability

3

Muscle spasm

Result of an injury to a muscle or a peripheral nerve, causes a tonic contraction.

4

What is a tonic contraction

A sustained Strong solid contraction over time

5

Muscle spasticity

Damage to the CNS resulting in exaggerated Stretch reflexes

6

What agents are used to treat muscle spasms

Polysynaptic inhibitors
Diazepam (Valium)

7

What are Polysynaptic inhibitors

They act on the Polysynaptic reflex arc to decrease excitability of alpha motor neuron

8

Common Polysynaptic inhibitor names

Carisoprodol
Chlorophenesin
Chlorzoxazone
Cyclobenzaprine
Metaxalone
Methocarbamol
Orphenadrine citrate

9

How do anti-spasm drugs work

Work through sedative effect

10

What shoulder be coupled with anti-spasm drugs during rehab

Aggressive PT

11

When and how should anti-spasm drugs be taken away

ASAP (3-4 days), and then use PT to continue anti-spasm effects

12

What type of agent is diazepam and what was it originally made for

Benzodiazepine, made as an anti-anxiey first

13

How does Diazepam(valium) work

Increases the inhibitory effects of GABA.

14

How does Valium increase the effects of GABA

GABA binds to the BDR protein allowing Cl- to enter the muscle making the muscle more negative and harder to excite. The Valium increases the binding of GABA so it can stay on the BDR protein longer and allow more Cl- to enter.

15

What is a draw back of Valium

Excess amounts will cause sedation

16

What agents are used to treat spasticity

Diazepam (Valium)
Baclofen
Alpha-2-agonists
Gabapentin
Dantrolene
Botulinum toxin

17

How does diazepam treat spasticity

Acts on the CNS to increase GABA mediated inhibition, also causes sedation

18

What is the best patient to treat with diazepam

Pt who has spasticity and anxiety issues

19

How does Baclofen work

Is a synthetic form of GABA which activates the receptors (GABAb) to open channels for Cl-

20

How is Baclofen administered

Orally or Intrathecally (spinal injection)

21

Why use intrathecal over oral

Takes less dosage to get same results
Better effect
Injected locally

22

What is a intrathecal Baclofen pump

Catheter placed in the abdomen that pumps the baclophen into the subarachnoid space at the level of the cauda equina

23

Drawbacks of the intrathecal Baclofen pump

Repitory problems
Stupor
Coma
Withdrawal if the pump malfunctions and does not pump anymore

24

What are alpha-2 agonists

Stimulate a receptor on interneurons in the spinal arc. These alpha-2 receptors inhibit the excitability of the interneurons

25

What is the primary agent that is a alpha-2 receptor

Tizanidine

26

How does Gabapentin work

Enhances GABA by blocking Calcium from entering and decreasing glutamate. More effective GABA means decreased excitability

27

How does dantrolene sodium (dantrium) work

Blocks the entry of Ca into skeletal muscle, so there is less actin/myosin interactions causing weaker or less muscle contractions

28

What makes dantrolene sodium different from other muscle relaxants

Is the only one that acts directly on the skeletal muscle where as the others act on the CNS

29

What is botulinum toxin

Local injections used for severe spasms such as torticollis and laryngospasms. Causes paralysis of muslce

30

Botulinum toxin mechanism of action

Eats up the connection proteins so the vessicles don't release AcH. Now when there is an action potential it will have no effect on the muscle.

31

How long does it take for botulinum to take effect and how long does it last

3-7 days
Lasts 2 to 3 months

32

What are some of the problems or limitations with botulinum

Immune system may create antibodies that destroy the toxin
Can only use on one muscle.
Must pick the muscle that you believe would increase function the most.

33

Signs of OD from Botulinum toxin

Drooping of eyes
Difficulty speaking
Muscle weakness
Respiratory problems

34

What are some concerns for muscle relaxants

Weakness
Sedation
Drastic change in tone in short time