NUR150: Chapter 25-Muscle Relaxants

Older patient is to receive a centrally acting skeletal muscle relaxant. Which of the follow would nurse expect to be prescribed? -bacolfen -carisoprodol -chlorzoxazone -cyclobenzaprine

carisoprodol

Cerebellum is associated with:

conscious muscle movement

A patient with a history of malignant hyperthermia is scheduled for surgery. Which agent would the nurse most likely expect to administer? -botulism toxin type B -dantrolene -baclofen -methocarbamol

dantrolene

A patient with amyotrophic lateral sclerosis is experiencing muscle spasticity. Which of the following drus would the nurse expect the physician to order? -chlorzoxazone -metaxalone -dantrolene -methocarbamol

dantrolene

Direct-Acting Skeletal Muscle Relaxants Prototype

dantrolene (Dantrium)

Pyramidal tract controls:

precise intentional movements

Simple reflex arcs comprise which of the following? -pyramidal tract -extrapyramidial tract -spindle gamma loop system -basal ganglia

spindle gamma loop system

When reviewing a patient's history, which condition would the nurse idenitfy contradicting the use of a centrally acting skeletal muscle relaxant? -epilepsy -cardiac disease -hepatic dysfunction -rheumatic disorder

rheumatic disorder

Extrapyramidal tract modulates:

unconscious controlled muscle activity (automatic adjustments in posture, position, and balance)

Basal Ganglia is associated with:

unconscious muscle movement

Central Acting Skeletal Muscle Relaxants (Contraindications/Cautions)

-Contraindications: allergy, rheumatic disorders, baclofen (not to be used for spasticity that contributes to locomotion, upright position, or increased function) -Cautions: epilepsy, cardiac dysfunction, muscle weakness conditions, hepatic/renal dysfunction (for metaxalone and tizanidine), -No studies during pregnancy/lactation

A patient is receiving botulism type A for frown line. The nurse would instruct patient about which of the following? -abnormal hair growth -acne -photo-sensitivity -drooping eyelids

-drooping eyelids

Central Acting Skeletal Muscle Relaxants (Adverse Reactions)

-drowsiness -fatigue -weakness -confusion -headache -GI (nausea, dry mouth, anorexia, constipation) -hypotension -urinary frequency, enuresis -chlorzoxazone may discolor urine orange-purple/red

Muscle Spasm

-often from injury to musculoskeletal system (overstretching a muscle, tendon, ligament) -flood of sensory impulses coming to spinal cord from injured area

Direct-Acting Skeletal Muscle Relaxants (Actions and Indications)

Actions: enter skeletal muscle directly -dantrolene: interferes with release of calcium from muscle tubules, preventing fibers from contracting -botulinum toxins: bind to receptor sites of motor nerve terminals- block release of acetylcholine (paralysis) -Injected locally -Treatment of spasticity affecting peripheral muscle contraction or from neuromuscular diseases -Cosmetic use reduced facial lines

Direct-Acting Skeletal Muscle Relaxants (Adverse Reactions and Drug Interactions)

Adverse Reactions: -fatigue -weakness -confusion -GI irritation -enuresis -botox- anaphylactic reactions, redness and edema at site -childre have developed botulism Drug Interactions: -estrogen -neuromuscular junction blockers, lincosamides, quinidine, magnesium sulfate, anticholinesteraces, suzzinylcholine, polymyxin or aminoglycosides

Botox (Type A)

Drug used to improve the appearance of moderate to severe glabellar lines.

Direct-Acting Skeletal Muscle Relaxants

Including: -dantrolene (Dantrium) *** -onabotulinumtoxin A (Botox) -rimabotulinum toxin B (Myobloc)

Complex Spinal Reflexes

Involves interneurons which communicate with related centers in the brain

Spinal Motor Neurons

Nerves that regulate posture, balance, and movement by a sequence of muscle contractions and relaxation.

Reflex Arc (Pathway of Impulses)

Relaxed muscle fiber -Spindle stretches ( in response to gravity) -Stimulates sensory nerve -Spinal cord -Stimulates gamma nerve -Muscle fiber contracts -No stretch -Sensory nerve not stimulated -Gamma nerve not stimulated -Muscle fiber relaxes

Which nursing diagnosis most likely would be the priority for a patient who is receiving a centrally acting skeletal muscle relaxant as treatment for acute knee strain? -deficient knowledge -risk for injury -acute pain -disturbed thought processes

acute pain

Signs/symptoms of which of the following would necessitate discontinuation of dantrolene therapy? -intermittent gastrointestinal upset -visual disturbances -urinary retention -hepatic dysfunction

hepatic dysfunction

Simple Spinal Reflexes

incoming sensory neuron and outgoing motor neuron

Which of the following would a nurse include when describing the action of dantrolene? -interferes with calcium release from the muscles -inhibition of the release of acetycholine -interference with the reflexes causing the spasm -inhibition of the presynaptic motor neurons in the central nervous system

interferes with calcium release from the muscles

The nurse instructs a patient about the possibility of his urine turning orange-purple/red if the patient were receiving which of the following? -baclofen -carisoprodol -chlorzoxazone -tizanidine

chlorzoxazone

Central Acting Skeletal Muscle Relaxants Prototype

baclofen (Lioresal)

Muscle Spasticity

-results from damage to neurons within the CNS -MAY result from increase of excitatory influence OR decrease in inhibitory influences -permanent condition for contractures: HYPERTONIA

Central Acting Skeletal Muscle Relaxants (Actions, Indications, Pharmacokinetics)

-Actions: exact mechanism unknown; thought to involve action in upper/spinal neurons -Indications: alleviation of signs/symptoms of spasticity; use in spinal cord injuries/diseases -Rapidly absorbed and metabolized in liver (baclofen is NOT metabolized); excreted in urine

Direct-Acting Skeletal Muscle Relaxants (Pharmacokintetics and Contraindications)

-slowly absorbed from GI tract -metabolized in liver, excreted in urine -Halftime: 4-8 hours Contraindications: allergy, spasticity that contributes to locomotion, upright position or increased function, hepatic disease, lactation Cautions: women, all patients older than 35, hx of liver disease, cardiac disease, respiratory depression, pregnancy

Action of Skeletal Muscle Relaxants Including: -baclofen (Lioresal) *** -carisoprodol (Soma) -chlorzoxazone (Parafron) -cyclobenzaprine (Amrix) -metaxalone (Skelaxin) -methocarbamol (Robaxin) -orphenadrine (Banflex) -tizanidine (Zanaflex) -diazepam (Valium)

-most work in brain and spinal cord -interfere with cycle of muscle spasm/pain by interfering with the reflexes that are caused by by spasms.

A patient is receiving baclofen at 8am. The nurse would monitor the patient for evidence of maximum effect at which time? -9am -10am -11am -12pm

10am

Central Acting Skeletal Muscle Relaxants (Drug Interactions)

CNS depressants Alcohol

Spinal Reflexes

simplest nerve pathways that monitor movement and posture