Conditions Effecting the Musculoskeletal System and PharmacotherapyPart Six: Muscle Spasm and Spasticity Flashcards
Exam 4 (Final)
Muscle Spasticity: What is it?
Group of movement disorders of CNS origin
Muscle Spasticity: Group of movement disorders of CNS origin
What increases?
Increased muscle tone
Increased DTRS, clonus
Muscle Spasticity: Group of movement disorders of CNS origin
Why does this occur?
Due to hyperexcitability of stretch reflex
Muscle Spasticity: Group of movement disorders of CNS origin
What does this result in?
Results in muscle being continuously contracted
Leads to stiffness/tightness
Muscle Spasticity: Group of movement disorders of CNS origin
What is there a loss in?
Loss of dexterity
Muscle Spasticity: Group of movement disorders of CNS origin
What is it dependent on? Also what phenomenon is involved?
Velocity-dependent
Clasp-knife phenomenon
Muscle Spasticity:
What are common causes?
Multiple sclerosis
Cerebral palsy
Muscle Spasticity:
Muscle relaxants: What do they do?
depress neuronal action in the CNS and may even augment neuronal inhibition in the skeletal muscles
Muscle Spasticity: What are the two main reasons drugs act?
Centrally acting
Direct actions on skeletal muscle
Muscle Spasticity:
Drug TX: 4 drugs
What are the four drugs?
Baclofen,
diazepam,
tizanidine
Dantrolene
Muscle Spasticity:
Drug TX: 4 drugs
Which drugs are centrally acting?
Baclofen,
diazepam,
tizanidine
Muscle Spasticity:
Centrally acting drugs:
What do they act on?
Act in CNS
Muscle Spasticity:
Centrally acting drugs:
What are they used for?
Used in cases of spasticity to repress hyperactive reflexes.
Muscle Spasticity:
What drugs have Direct actions on skeletal muscle?
Dantrolene
Muscle Spasm: What does it cause?
Painful & ↓ ability to function
Muscle Spasm: What is it?
Involuntary sudden contraction of a muscle or muscle group
Muscle Spasm: How does it occur?
Sudden onset, transient, localized
Muscle Spasm:
How are muscles? What feeling of muscles?
Visible muscle twitching, and a feeling of tightness or hardness in the affected muscle.
Muscle Spasm:
Variety of causes like…
Epilepsy
Hypocalcemia (tetany)
Acute and chronic pain syndromes
Trauma (localized muscle injury)
Muscle Spasm:
Physical measures include
PT
Specific exercises
Whirlpool baths
Heat application
⍉ cold ~ for pain & swelling, does not relieve spasm
Muscle Spasm:
Drug TX is what?
Analgesics
Centrally acting muscle relaxants
Muscle Spasm:
Drug TX are Analgesics like?
APAP, NSAIDs
Muscle Spasm:
Drug TX- Centrally acting muscle relaxants
like?
Cyclobenzaprine
Baclofen [Lioresal]
Mechanism:
Where does it act in?
Acts in the spinal cord
Baclofen [Lioresal]
Mechanism:
What does it do?
Suppresses hyperactive reflexes involved in regulation of muscle movement
Baclofen [Lioresal]
Mechanism:
What may it mimic?
May mimic the action of GABA on spinal neurons
Baclofen [Lioresal]
Mechanism:
What does it NOT do?
⍉ direct-muscle action so it does not ↓ muscle strength
It will not exacerbate muscle weakness, so it is preferred to direct-acting agent (Dantrolene)
Baclofen [Lioresal]
How can it be taken?
+/- food
Can be given intrathecal route via approved implantable pump
Baclofen [Lioresal]
Therapeutic uses include:
Reduce spasticity from Multiple Sclerosis, spinal cord injury
Decreases flexor and extensor spasms
Suppresses resistance to passive movement
These actions reduce the discomfort of spasticity and allow increased performance
Baclofen [Lioresal] (Cont.)
What are adverse effects:
CNS and gastrointestinal (GI) tract effects
Baclofen [Lioresal] (Cont.)
CNS and gastrointestinal (GI) tract effects
include: (CNS symptoms)
Drowsiness, dizziness, weakness, fatigue (diminish over time with cont’d use)
Baclofen [Lioresal] (Cont.)
CNS and gastrointestinal (GI) tract effects
include:
What are the GI symptoms?
Gastrointestinal symptoms (eg, nausea, constipation)
Baclofen [Lioresal] (Cont.)
CNS and gastrointestinal (GI) tract effects occur, so how should med be administered?
Small dose initially –> gradual increase
Baclofen [Lioresal] (Cont.)
Adverse effects: What can an overdose lead to?
Overdose can produce coma and respiratory depression – no antidote
Baclofen [Lioresal] (Cont.)
Adverse effects:
How should the med be withdrawn?
Gradual withdrawal over 1 to 2 weeks
Baclofen [Lioresal] (Cont.)
Adverse effects: What happens if there is an abrupt withdrawal (PO)?
Abrupt W/D PO: Visual hallucinations, paranoid ideation, and seizures
Baclofen [Lioresal] (Cont.)
Adverse effects: What happens if there is an abrupt withdrawal (intrathecal)?
Abrupt intrathecal withdrawal more dangerous:
Risk for rhabdomyolysis from muscle rigidity, higher fever, AMS, multiple organ system failure, exaggerated rebound spasticity, death
Baclofen [Lioresal] (Cont.)
Adverse effects: What can it lead to?
Urinary retention
Baclofen [Lioresal] (Cont.)
Contraindications/Interactions
Alcohol & other CNS depressants
Baclofen [Lioresal] (Cont.)
Contraindications/Interactions: What may the drug exacerbate?
May exacerbate psychiatric conditions
Baclofen [Lioresal] (Cont.)
Contraindications/Interactions: What should you monitor patients for?
Monitor pts with which urinary conditions? On which class of meds?
Diazepam [Valium]:
What family is it part of?
Member of the benzodiazepine family
Which drug in the benzodiazepine family can treat muscle spasticity?
Diazepam [Valium]
Diazepam [Valium]:
What is this drug considered?
Controlled substance
Diazepam [Valium]:
Mechanism: What does it act on?
Acts in the CNS
Diazepam [Valium]:
Use:?
Spasticity due to SCI or CNS condition
Musculoskeletal pain and muscle spasms
Diazepam [Valium]:
Mechanism: What does it mimic?
Mimics action of GABA to enhance presynaptic inhibition
Diazepam [Valium]:
Musculoskeletal pain and muscle spasms
pain, inflammation, trauma
Diazepam [Valium]:
What are adverse effects:
Sedation, CNS depression, hypotension
Diazepam [Valium]:
Adverse effects: What may it cause?
May cause paradoxical CNS stimulation or antegrade amnesia
Diazepam [Valium]:
Administration considerations:
How can tabs be given? How about oral solutions? IV?
Admin tabs with food or liquid.
Oral solution may be mixed with juice or soft foods
IV administration must be slow (maximum rate 5mg/min)
Dantrolene
MOA: What does it act directly on?
Acts directly on skeletal muscle
Dantrolene
MOA: When it acts directly on skeletal muscle what does it do?
Suppress release of Ca –> muscle less able to contract
Dantrolene
MOA: What does giving it in therapeutic doses do?
Therapeutic doses – minimal effect on smooth muscle & cardiac muscle ctx
Dantrolene
Uses?
Spasticity - MS, CP, SCI
Dantrolene
ADRs: What are the two main ones?
Significant reduction in strength (benefits must > risks)
Hepatic toxicity
Dantrolene
ADRs: Other ones? (7)
Muscle weakness
Drowsiness (systemic effects due to bloodstream distribution)
Diarrhea
Dysphagia
Hoarseness
N/V
Erectile dysfunction
Dantrolene (Adm how)
+/- food
Capsule maybe sprinkled on soft food
What is the most used centrally acting skeletal muscle relaxant
Cyclobenzaprine (Flexeril)
Cyclobenzaprine (Flexeril): Why is it given?
Rx’d to reduce spasms & pain caused by musculoskeletal injuries
Cyclobenzaprine (Flexeril):
MOA: Where does it work and what role does it play?
Works in brainstem - plays a crucial role in regulating muscle tone and reflexes.
Cyclobenzaprine (Flexeril):
MOA: What does it decrease? How? What does it not interfere with?
Decreases muscle activity by acting upon motor nerves but doesn’t interfere with muscle function
Reduction of tonic motor activity (stiffness)
Cyclobenzaprine (Flexeril):
Kinetics
Absorbed? How is it metabolized? How is it administered?
Absorption: PO, cyclobenzaprine is rapidly absorbed in GIT
Metabolism: In liver, CYP-450 pathway
Adm with/without food
Cyclobenzaprine (Flexeril):
Kinetics:
How much of the drug reached circulation? Why?
only 40%-50% of the drug reaches circulation due to first-pass metabolism
Cyclobenzaprine (Flexeril):
Kinetics: When does it peak?
Peaks in 4 hours, comes in ER – peak 7-8 hours
ADRs cyclobenzaprine
CNS depressant effects
Anticholinergic ADEs
Cardiac rhythm disturbances
ADRs cyclobenzaprine:
Anticholinergic ADEs: What does this drug do?
Antagonizes muscarinic receptors
ADRs cyclobenzaprine:
Anticholinergic ADEs:
Antagonizes muscarinic receptors-What does this mean?
~ ↑ fiber & fluid, stool softeners, photophobia, urinary retention, constipation, dry mouth
ADRs cyclobenzaprine:
What does this drug have structural similarities to?
Has structural similarities to tricyclic antidepressants (TCAs) and can influence serotonergic pathways.
ADRs cyclobenzaprine:
What is a major issue of this drug?
Serotonin Syndrome
ADRs cyclobenzaprine:
Serotonin syndrome: What does this mean you should be cautious with?
Caution w/ SSRIs, SNRIs, TCAs ~ serotonin syndrome
ADRs cyclobenzaprine:
Serotonin syndrome:
How does it effect the CNS?
CNS: agitation, restlessness, hallucinations, h/a, unconsciousness
ADRs cyclobenzaprine:
Serotonin syndrome:
What are autonomic symptoms of this?
Autonomic sx: diaphoresis, hyperthermia, htn, tachycardia, pupil dilation
ADRs cyclobenzaprine:
Serotonin syndrome:
What are Neuromuscular symptoms of this?
Neuromuscular: muscle twitch, tremors, ataxia –> seizures
ADRs cyclobenzaprine:
Serotonin syndrome:
What are GI symptoms of this?
n/v/d
ADRs cyclobenzaprine:
Nursing considerations: What should you inform patients about?
Inform pts about CNS depression & possible interactions with other drugs (etoh, benzos, opioids, antihistamines)
ADRs cyclobenzaprine:
Nursing considerations: What should you tell patients to report?
Report urinary retention
ADRs cyclobenzaprine:
Nursing considerations: What should you tell patients to do for dry mouth?
Chew sugar-free gum for dry mouth
ADRs cyclobenzaprine:
Nursing considerations: What should you tell patients to do for photophobia?
Wear sunglasses to manage photophobia r/t dilated pupils
Pt education for CNS muscle relaxants for spasms:
Why should you avoid abrupt DC of drugs?
Avoid abrupt d/c to prevent abstinence syndrome/withdrawal
Pt education for CNS muscle relaxants for spasms:
Avoid abrupt DC of drugs: Avoid abrupt d/c to prevent abstinence syndrome/withdrawal
Chronic high-dose tx can cause physical dependence if drugs abruptly withdrawn
Pt education for CNS muscle relaxants for spasms
How long are drugs for spasms taken?
Drugs for spasm are usually taken for no longer than a few wks
Pt education for CNS muscle relaxants for spasms
What should you avoid doing with drugs? Why?
Avoid combining muscle relaxants with alcohol and CNS depressants
CNS effects may be intensified.
Pt education for CNS muscle relaxants for spasms:
What kind of side effects should you report?
Report side effects of the muscle relaxant, including nausea, vomiting, dizziness, fainting, headache, and diplopia.
Pt education for CNS muscle relaxants for spasms:
How should you take muscle relaxants to avoid GI upset?
Take muscle relaxants with food to avoid GI upset.
Pt education for CNS muscle relaxants for spasms:
When should you use OTC meds with muscle relaxants?
Advise to avoid use of OTC meds (e.g., cough preparations, antihistamines) unless directed by the health care provider.
Pt education for CNS muscle relaxants for spasms
Why would they cause drowsiness initially?
CNS depressant effect of all central muscle relaxants may cause severe drowsiness initially
Pt education for CNS muscle relaxants for spasms
What shouldn’t you do while taking this drug (activity wise)?
Do not to drive, operate heavy machinery, or make important legally-binding decisions when taking muscle relaxants (sedative effects and may cause drowsiness).
Lifespan concerns:
What is diazepam associated with?
Diazepam is associated with low birth weights, prematurity, hypoglycemia, and respiratory depression.
Lifespan concerns:
What has been seen in neonates taking diazapam?
Neonatal withdrawal syndrome has been observed with benzodiazepines.
Lifespan concerns:
What effect does baclofen, tizanidine, and dantrolene have in pregnancy?
Animal studies have yielded adverse events for baclofen, tizanidine, and dantrolene in pregnancy.
These drugs can cause adverse effects in infants.
Lifespan concerns:
What is not recommended for newborns while taking drugs?
Breast-feeding is not recommended.
Lifespan concerns:
At the dosage required to have adequate effect, these drugs may cause what?
At the dosage required to have adequate effect, these drugs may cause sedation and cognitive impairment, thus creating a fall risk in older adults.
Long-acting benzodiazepines (e.g. diazepam is an issue for older adult patients) what are the issues?
slower metabolism, elimination may be delayed, and active drug may accumulate.
Cyclobenzaprine: some criteria?
Cyclobenzaprine – Beer’s criteria
potentially inappropriate for older adults.
LOOK AT SLIDE 13 VERY IMPORTANT!!
