Skeletal Muscle Relaxants
How would a nurse show respect when offering a prescription to Pacific Islanders regarding muscle relaxants?
Use two hands when presenting the information.
Where is cyclobenzaprine excreted?
kidneys
A patient who has been on oral muscle relaxants for 6 weeks asks for a prescription renewal. When contacting the health care provider, what is the nurse most concerned about?
Length of time patient has been on medication
A nurse is providing discharge teaching to a patient prescribed cyclobenzaprine. Which statement would be most appropriate?
"Notify your health care provider if you think you might be pregnant."
Which statement made by Ms. Wilson regarding cyclobenzaprine indicates further teaching is required by the nurse?
"I can take this medication as long as I want."
A patient has been prescribed a skeletal muscle relaxant and asks the nurse, "Why was I told not to drive or participate in activities that require mental alertness while taking this drug?" How should the nurse respond?
"Sedation is a common side effect of skeletal muscle relaxants."
What is the onset of action for cyclobenzaprine?
1 hour
The nurse educates a patient to avoid which drugs while taking muscle relaxants?
1. Alcohol 2. Kava kava 3. Valerian
Which are two common side effects of centrally-acting muscle relaxants?
1. Dizziness 2. Drowsiness
Which side effects of muscle relaxants should patients report to the health care provider?
1. Headache 2. Nausea 3. Muscle weakness
Which nursing assessments are important for a patient prescribed cyclobenzaprine?
1. Level of consciousness 2. Breathing 3. Blood pressure
The nurse will teach the patient that cyclobenzaprine can relieve which symptoms?
1. Muscle stiffness 2. Localized muscle spasms 3. Pain with range of motion
What is the duration of action of cyclobenzaprine?
12-24 hours
Interactions of Cyclobenzaprine
Concomitant use of cyclobenzaprine with other sedative drugs or herbal supplements can result in increased CNS depression. Extreme caution needs to be used to avoid accidental overdose. It is recommended that concomitant use be discontinued or the dosage of either drug be decreased. Drugs: Alcohol, barbiturates, tricyclic antidepressants, sedative-hypnotics, and other CNS depressants will increase sedation. MAOIs may increase the risk of hypertensive crisis and seizures. Tramadol may increase the risk of seizures. Herbs: Kava, valerian, gotu kola, SAMe, and St. John's wort may interact with cyclobenzaprine. Food: No known interactions exist.
Cultural Considerations
Cultural differences of patients should be considered when offering prescriptions and teaching information. Teaching methods should meet the needs of the patients and their family members. It is important to use both hands when offering a prescriptions, instructions, or pamphlets to Asian and Pacific Islander patients as a sign of respect. The nurse should demonstrate respect by addressing patients and their families formally until instructed otherwise and refraining from asking private questions in public.
Dosage and Administration of Cyclobenzaprine
Cyclobenzaprine is available in a 5-mg and 10-mg doses and in an extended-release formulation. Adults and adolescents 15 years and older 5 mg PO tid Dosage may be increased to 10 mg PO tid if needed Adults PO extended release: 15-30 mg daily
Pharmacodynamics and Pharmacokinetics of Cyclobenzaprine
Cyclobenzaprine is the most commonly used drug in this class, and is often prescribed to reduce spasms caused by musculoskeletal injuries. It is not effective against muscle spasms caused by central nervous system disorders.
In which way do centrally-acting muscle relaxants relieve muscular spasms and pain associated with traumatic injuries and spasticity from chronic debilitating disorders?
Depress neuron activity in the spinal cord or brain or by enhancing neuronal inhibition on the skeletal muscles.
Where is cyclobenzaprine absorbed?
Gastrointestinal (GI) tract
Pre-Administration Assessment for Cyclobenzaprine
Harm from medications can be an unintended consequence of treatment, but can also be the result of ineffective patient screening. It is vital for the nurse administering cyclobenzaprine to do the following prior to administration: Collect a thorough medical history. The patient's health history is needed to identify the cause of the muscle spasms; cyclobenzaprine is only effective for muscle spasms of local origin. Obtain baseline vital signs. Obtain the patient's current or most recent drug history to help avoid any possible drug interactions.
Use of all muscle relaxants is contraindicated in patients with which condition?
Hepatic disease
Interventions and Evaluation for Cyclobenzaprine
It is imperative that the nurse administering cyclobenzaprine be aware of the interventions needed to maintain patient safety during the administration and/or evaluation of cyclobenzaprine. Interventions: Record the patient's vital signs prior to administration and report any abnormal results. Observe the patient for any CNS side effects or CNS depression (e.g., dizziness, hypotension, or decreased respirations). Assist the patient with ambulation if necessary to prevent falls. Administer the medication with food or milk if GI upset occurs. Evaluation: Evaluate the effectiveness of the medication by using a pain scale to determine whether the patient's muscular pain and/or spasms have diminished. Be alert to both verbal and non-verbal indications of pain and/or pain relief. Evaluate the patient for decreased stiffness and swelling, increased joint mobility, reduced joint tenderness, and improved grip strength.
Which lab values would need to be monitored based on the metabolism of cyclobenzaprine?
Liver function tests
A patient is complaining of gastrointestinal symptoms when taking a prescribed muscle relaxant. What should the patient drink to help with these symptoms?
Milk
Case Study
Ms. Wilson is a 22-year-old female who is seen in the pain clinic with complaints of stiffness in her neck, limited cervical range of motion, and shooting pains down her right arm accompanied by some numbness and tingling in the index finger of her right hand. She has experienced this discomfort for approximately 3 weeks and has participated in physical therapy twice weekly without any relief. The health care provider prescribes cyclobenzaprine 5 mg po TID prn for muscle spasms, as well as ibuprofen 600 mg po TID. An MRI of the cervical spine has been ordered, and Ms. Wilson has been instructed to return to the clinic after the MRI to meet with the health care provider for follow up.
Overview of Skeletal Muscle Relaxants
Muscle relaxants are medications used to relieve muscular spasms and the pain associated with these spasms. Muscle spasms may be attributed to traumatic injuries or chronic debilitating diseases (e.g., MS, CVA, cerebral palsy, or head or spinal cord injuries). Spasticity can result from either increased muscle tone caused by increased CNS stimulation from cerebral neurons or from a lack of inhibition in the spinal cord or the skeletal muscles. Muscle relaxants depress neuronal action in the spinal cord or brain and may even augment neuronal inhibition in the skeletal muscles.
Summary
Muscle relaxants have sedative effects and should not be taken with other CNS depressants, such as alcohol, prescription narcotics, and barbiturates. Because muscle relaxants can cause marked sedation, CNS depression, and dizziness, patients should use extreme caution when taking these medications. The most commonly used muscle relaxant is cyclobenzaprine. It is important to note that cyclobenzaprine use is contraindicated in children and in patients concurrently taking MAOI therapy, as well as individuals with spinal cord injuries, cerebral palsy, hyperthyroidism, paralytic ileus, and heart disease. It is the nurse's job to provide patient teaching and instruct the patient to avoid alcohol and other CNS depressants when using muscle relaxants. The nurse should stress the fact that when muscle relaxants are used concomitantly with these items, CNS effects may be intensified. The nurse should provide the patient with proper and accurate teaching regarding correct dosages and administration techniques for muscle relaxants and advise the patient of specific adverse effects that can result from muscle relaxant use. Cyclobenzaprine can be effective in treating muscle spasms, but patients must use caution and comply with the instructions given in order to prevent adverse drug effects.
What causes dizziness and fainting in patients taking muscle relaxants?
Orthostatic (postural) hypotension
Patient Teaching for Cyclobenzaprine
Patient teaching regarding cyclobenzaprine helps ensure patient safety and prevent adverse effects from this medication. General Teaching Teach the patient that the muscle relaxant should not be abruptly stopped and that it should be tapered over 1 week to avoid rebound muscle spasms. Advise the patient not to drive, operate heavy machinery, or make important legally-binding decisions when taking muscle relaxants. These medications have sedative effects and may cause drowsiness. Inform the patient that most centrally acting muscle relaxants for acute spasms are usually taken for no longer than a few weeks. Teach the patient to avoid combining muscle relaxants with alcohol and CNS depressants. If muscle relaxants are taken concomitantly, CNS effects may be intensified. Advise the patient that these drugs must be used cautiously in pregnant women and nursing mothers. Side Effects Encourage the patient to report side effects of the muscle relaxant, including nausea, vomiting, dizziness, fainting, headache, and diplopia. Diet Advise the patient to take muscle relaxants with food to avoid GI upset.
Contraindications of Cyclobenzaprine
Patients can display signs of sedation from use of cyclobenzaprine, so it should be used with great caution. The nurse should collect a thorough medical history to determine the presence of any contraindications to cyclobenzaprine. Cyclobenzaprine use is contraindicated in patients with certain cardiovascular disorders (e.g., acute myocardial infarction, AV block, bradycardia, bundle-branch block, cardiac arrhythmia, hypokalemia, HTN, QT prolongation on EKG, or heart failure), hyperthyroidism, and hepatic impairment and in patients taking MAOIs. Cyclobenzaprine and orphenadrine use are contraindicated in patients with narrow-angle glaucoma or myasthenia gravis. Cyclobenzaprine use is contraindicated in children and in individuals with spinal cord injuries, cerebral palsy, or paralytic ileus. Caution should be used in individuals with seizure disorders, glaucoma, prostatic hypertrophy, urinary retention, or hepatic disease and with patients who breastfeed, drive or operate machinery, concurrently ingest alcohol or other CNS depressants, are older adults, or have regular sunlight or UV light exposure.
Muscle Spasms
Several muscle relaxants can be prescribed in an effort to decrease pain associated with muscle spasms and increase range of motion. Many of these medications are known to have a sedative effect and should not be taken in addition to CNS depressants such as alcohol, prescription narcotics, or barbiturates. Many of these medications, with the exception of cyclobenzaprine, may also lead to drug dependence. Vertigo and drowsiness are common side effects of these medications. Carisoprodol, chlorzoxazone, cyclobenzaprine, metaxalone, methocarbamol, and orphenadrine citrate are all examples of centrally acting muscle relaxants.
Spasticity
Skeletal muscle spasticity is a form of muscular hyperactivity that causes painful contractions of the muscles, resulting in limited mobility. Centrally acting muscle relaxants act on the spinal muscles. Baclofen, dantrolene, and tizanidine are all examples of centrally acting muscle relaxants used to treat spasticity. Diazepam, a benzodiazepine, has also been successfully used to treat muscle spasticity.
Patients should change positions purposefully and slowly when taking muscle relaxants to prevent which condition?
Syncope or dizziness
The nurse plans on providing patient teaching to Ms. Wilson regarding cyclobenzaprine. Which would be considered appropriate information for the nurse to share with Ms. Wilson?
Teach Ms. Wilson to avoid concomitant use with alcohol and other CNS depressants.
Centrally Acting Muscle Relaxants
The actual mechanism of action of muscle relaxants is not entirely known. Centrally acting muscle relaxants are prescribed in cases of spasticity to repress hyperactive reflexes. They are also prescribed for muscle spasms that are resistant to antiinflammatory medications, physical therapy, or other treatment modalities.
Pharmacodynamics
The exact mechanism of action of cyclobenzaprine is unknown, but it is believed to block nerve impulses at the brainstem level.
Adverse Effects of Cyclobenzaprine
The main adverse effects of muscle relaxants result from their effects on the CNS and skeletal muscles. Feelings of euphoria, lightheadedness, dizziness, drowsiness, fatigue, confusion, and muscle weakness may be experienced early in treatment. Many of these adverse side effects are transient and will subside as patients grow tolerant to the medications and their side effects over time. Less common adverse effects include diarrhea, GI upset, headache, slurred speech, muscle stiffness, constipation, sexual difficulties in males, hypotension, tachycardia, and weight gain. To reduce GI upset, it is recommended that patients take the medications with food or milk. Serious adverse reactions include allergic reaction, angioedema, myocardial infarction, seizures, and ileus.
Pharmacokinetics
The pharmacokinetics of cyclobenzaprine are as follows: Onset of action: 1 hour Peak plasma concentration: 3-8 hours Duration of action: 12-24 hours Absorption: PO, well absorbed Distribution: 93% protein bound Metabolism: In liver, half-life of 8-37 hours Excretion: In urine
What is the rationale in teaching a patient that the muscle relaxant should not be abruptly stopped?
To avoid rebound spasms.
Why should a patient taking cyclobenzaprine report any side effects to the health care provider?
To prevent respiratory depression
