Please enable JavaScript.
Coggle requires JavaScript to display documents.
SKELETAL MUSCLE RELAXANTS (CENTRALLY ACTING MUSCLE RELAXANTS…
SKELETAL MUSCLE RELAXANTS
CENTRALLY ACTING MUSCLE RELAXANTS
MECHANISM OF ACTION
The exact mechanism of action of skeletal muscle relaxants is not fully understood but it is thought that it involves the participation of upper or spinal interneurons.
It inhibits monosynaptic and polysynaptic spinal reflexes. Other than that, it is a CNS depressant.
INDICATIONS
Primary indication is relief of discomfort associated with acute, painful musculoskeletal conditions as adjunct to rest, physical therapy, and other measures.
Alleviation of signs and symptoms of spasticity, may be of use in spinal cord injuries or spinal cord diseases.
ORAL ROUTE OF ADMINISTRATION
Oral route of administration
CONTRAINDICATIONS
Allergy to centrally acting skeletal muscle relaxants.
Skeletal muscle spasms caused by rheumatic disorders.
History of epilepsy. CNS depression and imbalance caused by drugs may exacerbate seizure disorder.
Cardiac dysfunction. Muscle function may be depressed.
Condition marked by muscle weakness. Can be exacerbated by drugs.
Hepatic, renal dysfunction. Interfere with drug metabolism and excretion.
Baclofen is not indicated for treatment of spasticity that contributes to locomotion, upright function, or increased function.
SIDE EFFECTS
CNS: depression, drowsiness, fatigue, weakness, confusion, headache, insomnia.
CV: hypotension, arrhythmias
GI: nausea, dry mouth, anorexia, constipation.
GU: urinary frequency, enuresis, urinary urgency
Chlorzoxazone may turn urine into purple-red color.
Tizanidine has been associated with liver toxicity and hypotension in some patients.
Baclofen is tapered over 1-2 weeks to prevent development of psychoses and hallucinations.
NURSING CONSIDERATIONS
NURSING ASSESSMENT
Assess for mentioned contraindications and cautions (e.g. drug allergy, cardiac depression, rheumatic disorder, pregnancy and lactation, etc.)
Conduct thorough physical assessment (temperature, skin color and lesion, CNS orientation, affect, reflexes, bilateral grip strength, spasticity evaluation; bowel sounds and urine output)
Monitor liver and renal function tests to detect potential adverse effects.
NURSING DIAGNOSES
Acute pain related to GI and CNS effects
Disturbed thought processes related to CNS effects
Risk for injury related to CNS effects
IMPLEMENTATION
Provide additional spasm and pain relief like rest periods, heat application, NSAIDs as ordered, and positioning to augment the effects of the drug at relieving the musculoskeletal discomfort.
Discontinue drug at any sign of liver and renal dysfunction to prevent severe toxicity.
Monitor respiratory status to evaluate adverse effects and arrange for appropriate dose adjustment or discontinuation of the drug.
Provide comfort measures to help patient tolerate drug effects.
Provide safety measures (e.g. adequate lighting, raised side rails, etc.) to prevent injuries.
Educate client on drug therapy to promote understanding and compliance.
EVALUATION
Monitor patient response to therapy (improvement in muscle spasm and relief of pain; improvement in muscle spasticity).
Monitor for adverse effects (e.g.CNS changes, GI depression, urinary urgency, etc).
Evaluate patient understanding on drug therapy by asking patient to name the drug, its indication, and adverse effects to watch for.
Monitor patient compliance to drug therapy.
STORAGE CONDITION
Store out of reach of children
Do not store in direct sunlight
EXAMPLES OF CENTRALLY ACTING MUSCLE RELAXANTS
carisoprodol
Paraflex
methocarbamol
DIRECT-ACTING SKELETAL MUSCLE RELAXANTS
MECHANISM OF ACTION
Dantrolene acts within skeletal muscle fibers and interfere with calcium ion release from the muscle tubules. .
Therefore, the fibers are prevented from contracting.
It does not interfere with neuromuscular transmission and does not affect skeletal muscle surface membrane
INDICATIONS
CHILDREN
Safety and effectiveness not established in children.
Dantrolene is used to treat upper motor neuron spasticity in children.
Dose should be accurately calculated based on body weight and it increases over time.
Children are at increased risk of CNS and GI toxicity.
ADULTS
They should be cautioned to avoid activities that require alertness (e.g. driving) because drugs can cause confusion and drowsiness.
Pregnant and lactating women should be advised to use contraception and alternative method of feeding, respectively.
Premenopausal women are at increased risk for hepatotoxicity in association with use of dantrolene.
ROUTE OF ADMINISTRATION
Intravenous route
Oral route of administration
CONTRAINDICATIONS
Allergy to direct-acting skeletal muscle relaxants. Prevent hypersensitivity reactions
Spasticity that contributes to locomotion, upright position, increased function.
Active hepatic disease. Interfere with metabolism of drug
Pregnancy. Potential adverse effects to the fetus
Lactation. May cross breast milk and may cause adverse effects in the infant
Women and patients older than age 35. Caution is applied because of increased risk of potentially fatal hepatocellular disease
History of liver disease or previous dysfunction. Increases liver’s susceptibility to cellular toxicity
Respiratory depression. Exacerbated by muscular weakness
Cardiac disease. Cardiac muscle depression may be a risk
SIDE EFFECTS
CNS: drowsiness, fatigue, weakness, confusion, headache, insomnia, visual disturbances
GI: GI irritation, diarrhea, constipation, abdominal cramps
GU: urinary frequency, enuresis, urinary urgency , crystalline urine with pain or burning on urination
Others: acne, abnormal hair growth, rashes, photosensitivity, abnormal sweating, chills, nyalgia
Dantrolene can cause direct hepatocellular damage and potentially fatal hepatitis
Botulinom toxins are associated with anaphylactic reactions characterized by headache, dizziness, muscle pain, paralysis
NURSING CONSIDERATIONS
NURSING ASSESSMENT
Assess for mentioned contraindications and cautions (e.g. drug allergy, cardiac depression, rheumatic disorder, pregnancy and lactation, etc.)
Conduct thorough physical assessment (temperature, skin color and lesion, CNS orientation, affect, reflexes, bilateral grip strength, spasticity evaluation; bowel sounds and urine output) to obtain baseline data.
Monitor liver and renal function tests to detect potential adverse effects.
NURSING DIAGNOSES
Acute pain related to GI and CNS effects
Disturbed thought processes related to CNS effects
Risk for injury related to CNS effects
IMPLEMENTATION
Assess area before administering botulinum toxins because area with active infection will be exacerbated by injection.
Monitor intravenous access sites of dantrolene for potential extravasation because drug is alkaline and very irritating to tissues.
Periodically discontinue dantrolene for 2-4 days as ordered to monitor therapeutic effectiveness.
Discontinue drug at any sign of liver dysfunction to prevent adverse effects.
Provide comfort measures to help patient tolerate drug effects.
Provide safety measures (e.g. adequate lighting, raised side rails, etc.) to prevent injuries.
Educate client on drug therapy to promote understanding and compliance.
EVALUATION
Monitor patient response to therapy (improvement in spasticity, movement and activities).
Monitor for adverse effects (e.g. CNS changes, diarrhea, liver toxicity, etc).
Evaluate patient understanding on drug therapy by asking patient to name the drug, its indication, and adverse effects to watch for.
Monitor patient compliance to drug therapy.
STORAGE CONDITION
Do not place the medication in direct sunlight
Store out of reach of children
EXAMPLES OF DIRECT- ACTING SKELETAL MUSCLE RELAXANTS
botulinum toxin type A
botulinum toxin type B
Dantrium