Chapter 21: Neuromuscular Medications Flashcards
what are neurodegenerative diseases?
progressive, irreversible loss of neuron function in the brain and/or spinal cord
what is a common problem with many neuromuscular diseases?
depression
what is parkinsons disease?
progressive, neurodegenerative disorder characterized by abnormal motor movement
what are initial signs of parkinsons?
fatigue, slight tremour, slow movement (bradykinesia)
what is the mean age for parkinsons and who does it affect more?
40-70, men
what are the cardinal signs of parkinsons?
-tremor: hands and head develop a palsy-like, continuous motion or shaking at rest, and pill rolling (thumb and forearm rub together in circular motions)
-muscle rigidity: resistance to passive movement of arms and legs, can resemble arthritis, rigidity of facial muscles, and uncontrollable drolling
-bradykinesia: slowed down movement and speech, difficulty chewing/swallowin/speaking, shuffled gait
-postural instability: stooped over, hard to maintain balance, and frequent stumbling
what is Parkinsons caused by?
Decrease in dopamine which is produced by substantial nigra. Also causing Ach to have a more dramatic effect (neurotransmitter for PNS)
what is the goal and how long does it take to see results from parkinson meds?
to balance dopamine and ach, 2-3 weeks
what is wearing off effect, on/off syndrome, and extrapyramdial symptoms?
-wearing- off: when a pt takes a med for a prolonged period, the drugs effectiveness wears off closing to the end of the dosing interval
-on/off: pt alternates between symptom-free peroids and times when the drug stop working briefly
-extrapyramidal: adverse effects that develop from a deficiency of dopamine, not causes by parkinson, usually by antipsychotic meds
what 2 types of drugs are used for Parkinsons?
dopamine agonists and anticholinergic drugs
what is the most effective dopamine replacement drug?
levodopa
what does levodopa do?
It enters the blood-brain barrier (because dopamine is a polar molecule, and the BBB blocks polar molecules), and enzymes in the brain convert levodopa into dopamine
what is levodopa taken with?
Carbidopa
-together they’re called Sinemet
-carbidopa inhibits the metabolism of levodopa, causing a greater portion of levodopa to cross the BBB
-carbidopa allows for more of levodopa to be increased
-it also allows for a lower dosage of levodopa perscribed for the pt
what is the prototype drug for dopamine replacement?
levodopa and carbidopa
what are the adverse effects of levodopa?
GI: n/v, flatulence, abdominal distress, dysphagia, anorexia
CNs: anxiety, confusion, agitation, headache, nightmares, insomnia,
MSKL: hand tremors, involuntary movements, twitching, numbness, choreiform
Anti-cholinergic: urinary retention, dry mouth
what are the serious ADR for levodopa?
leukopenia, agranulocytosis, hemolytic anemia
what are contraindications for levodopa?
-hypersensitivity
-acute psychosis
-severe psychoneuroses
-narrow angle glaucoma
-use of MAOIs within 2 weeks
what are nursing considerations for levodopa?
-take on an empty stomach
-do not take with multi-vit
-have a low protein diet
-monitor VS (rr, hr, and bp)
-no alcohol
-monitor liver and kidney
-monitor for safety with ambulation due to dizziness
-watch for mood or behaviour changes
when can dopamine agonists be used?
as a monotherapy during early stages or as adjuncts to levodopa in advanced stages
what do dopamine agonist do?
activate dopamine receptors without increase dopamine
are dopamine agonist more or less effective than levodopa?
less effective, but have less adverse side effects like no toxic metabolites, no need for low protein diet, lower risk for dyskinesia (involuntary uncontrollable muscle movements) and lower incidence of wearing off effect
what are the two classifications of dopamine agonist?
ergot and non-ergot alkaloids
what is the prototype drug for non-ergot alkoids?
pramipexole (mirapex)
what are adverse and serious effects of pramipexole?
adverse: hallucinations, drowsiness, dizziness, insomnia, orthostatic hypotension, dyskinesia, nausea, agitation
serious: sleep attacks, and the 3 from levodopa
what are considerations for pramipexole?
-assess for baseline vitals and symptoms of Parkinsons
-assess mental status
-monitor for orthostatic hypotension
-monitor for tardive dyskinesia (invol repetitive movements)
-alert pt and family about sleep attacks
-ensure family knows PD treatment does not cure but may help with symtoms for a period of time
what are some adjuncts to levodopa therapy?
-amantadine (symmetrel): increase release of dopamine by the storage sites
-COMT inhibitors: prevent destruction of levodopa, adjuncts to levodopa, eg. entacapone (comtan), and tolcapone (tasmar)
-monoamine oxidase b inhibitors: selegilene (eldepryl), may slow down the progression fo PD but effectivness not clearly established
what are anticholinergic drugs for?
oldest of the antiparkinsons, and are effective are reducing tremor not bradykinesia
how do anticholinergic drugs work?
restore balance between ach and dopamine by blocking muscarinic receptors in the striatum, inhibiting effects of Ach
what is the prototype drug for anticholinergics for parkinsons?
Benztropine (cogentin)
what are the adverse effects of benztropine (cogentin)? (7)
CNS: blurry vision, sedation, confusion
GI/GU: constipation, urinary retention, dry mouth
decreased sweating
what is a serious adverse effect of benztropine (cogentin)?
paralytic ileus
what is a major contraindication of benztropine (cogentin)?
alcohol
what is the treatment for overdose of benztropine (cogentin)?
physostigmine, 1-2mg SQ or IV to reverse s/s of anticholinergic intoxication
with benztropine (cogentin), what drugs are for additive toxicity, sedative effect and slow down GI/decrease absorption?
-additive toxicity: MAOIs, antihistamine, tricyclic antedepressants, phenothiazines , quinidine
-additive sedative: alcohol, CNS depressants
-slow Gi motility/decrease absorption: antidiarrheals
what is the most common type of dementia?
alzheimers
what is dementia?
chronic, degenerative disorder characterized by progressive memory loss, confusion, inability to think or communicate effectively
what is an early sign of dopamine?
loss of short term memory
what are drugs used for alzhemiers?
cholinesterase inhibitors, cholinesterase breaks down acetycholine, but in alzhemiers there is already not enough acetycholine
what neurotransmitter is deficient in alzhemiers?
acetylocholine, meaning dopamine has a more drastic effect = bear
what is the goal of alzheimer medications?
to improve ADLS, behaviour, cognition
what are side effects of cholinesterase inhibitors?
mostly GI like n/v, diarrhea and the liver
what do reversible cholinesterase inhibitors do?
-raise acet concentrations in the brain
-side effects are typically GI related
-serious side effects include a fib, sinu bradycardia, and seizures
what is the prototype drug for reversible cholinesterase inhibitors?
Donepezil (aricept)
what are adverse and serous side effects of donepezil?
adverse
-GI: n/v/d and anorexia
MSKL: muscle cramps, joint pain, bruise
CNS: fainting, fatigue, headache, abnormal dreams/ hallucination
serious
-life threathening dysrhythmias (a fib, and sinus bradycardia)
-seizures
-renal failure or hepatotoxity
what is txt of overdose for donepezil (aricept)
anticholinergic drugs
what are nursing considerations for donepezil (aricept)
-determine safety and cognitive functioning
-obtain baseline lab test esp liver and renal
-determine s/s of alzheimer
-ensure family knows to monitor pt for abnormal heart beat or if the pt feels “butterflies” in their chest
-avoid alcohol
-encourage participation in support group and include family
-evaluate need for alternative living arrangements
what is multiple sclerosis?
-autoimmune disease caused by the demyelinated secondary to inflammatory response
-exact cause not known
-leading cause of neurologica disability in 20 to 40 age group
-symptoms include: difficulty maintaining balance, muscle weakness and cold sensitivity
what drugs are used for MS?
-immunomodulators: drugs that impact the immune response, either stimulate or inhibit response
-used to prevent exacerbations
what is amyotrophic lateral sclerosis/lou gehrig disease?
-most common degenerative disease of the motor neurons
-characterized by weakness and atrophy of muscles of the legs, forearm and hands , which eventually spread to all muscles of the body
-death in 2-3 years from resp failure or pneumonia
-the only approved drug is riluzole (rilutek) for ALS, reduces degeneration of neurons, may also treat symptoms with muscle relaxants and anticholinergics
what are muscle spasm vs muscle spasticity?
spasm: involuntary contractions most commonly caused by injury or overuse of skeletal muscles
spasticity: caused by neuromuscular disorders
what are the two types of muscle spasms?
-spasms are involuntary contraction specific to a muscle group
-two types are: tonic (single and prolonged) and clonic (rapidly repeating)
what are causes of muscle spasm?
-skeletal muscle overuse/injury
-dehydration
-electrolyte imbalance/hypokalemia
-related pathologies
-MS, epilepsy, muscular dystrophy, fractures, chronic low back pain
what are meds you can take for muscle spasms?
-NSAIDS: relieve pain + inflammation, eg, aspirin, naproxen, ibuprofen
-muscle relaxants: for moderate to severe spasms, relax tight contracted muscles, can be used with NSAIDS
-centrally acting muscle relaxants
what is the prototype drug for centrally acting muscle relaxants?
-cyclobenzaprine (amrix, flexeril)
-increases NE to produce anticholinergic effect
what are nursing considerations for cyclobenzaprine?
-VS and physical assessment, history
-baseline neurological status
-assess for pain
-protect from injury related to falls from drowsiness
asses for rash, ithcing, hives
-inform pt not to drive
what is methocarbamol (relaxin, robaxin)
-a drug similar to cyclobenzaprine
-its an adjunct to physical therpay interventions
-don’t drive
what is Metaxalone (skelaxin)
-a drug similar to cyclobenzaprine
-ineffective txt in spasticity-related neurological disorders
what is orphenadrine (banflex, myophen, norflex) ?
-a drug similar to cyclobenzaprine
-anticholingeric drug of the antihistamine class: it is closely related to diphenhydramine
what is tizandine (zanaflex)
-a drug similar to cyclobenzaprine
-spasticity related to the brain or spinal cord injury of MS
what is muscle splascity?
-continuous state of contraction
-pain is more intense than spasms and causes greater impairment
-irritable deep tendon reflexes
-fixed joint movement
-not a disorder itself but rather causes by neuromuscular diseases
what is the prototype drug for muscle spasticity?
dantrole (dantrium), which directly relaxes splastic muscles
what are nrsg considerations for dantrolene?
-history and prescription
-baseline pain and neurological status
-assess vitals during iV admin
-assess for cardiopulmonary changes
(monitor breath and heart sounds)
-do liver function tests, report signs of jaundice, avoid alcohol
-do not drive
what is a drug similar to dantrole?
botox, inhibits release of ach paralyzing the muscle
what are nonpharmalogical therapies?
-physical therapy: increase movements, and prevents contractures
-herbal remedies: black cohosh, castor oil packs, capsaicin - wear with gloves (all topic)
-b complex vits, specifically B6
