Nursing care
Muscle Relaxants: what to check before you give it
Written and reviewed by Dana Whitfield, RN, MSN · 5 min read · Updated September 2026
Short answer
Muscle relaxants such as cyclobenzaprine and baclofen treat spasticity and musculoskeletal spasm, but nearly all of them sedate the central nervous system, which raises fall risk in every setting. Baclofen carries an added rule: abrupt discontinuation in a patient with spasticity can trigger withdrawal seizures, hallucinations, or a life-threatening rebound in muscle tone, so it is always tapered.
What it does and why it is prescribed
Muscle relaxants fall into two broad groups. Antispasmodics like cyclobenzaprine treat short-term musculoskeletal spasm — the kind that follows a back strain or acute injury — by acting centrally on the brainstem rather than on the muscle itself. Antispastics like baclofen treat spasticity from chronic neurological conditions such as multiple sclerosis or spinal cord injury, where muscle tone stays pathologically increased.
That distinction matters because the two groups are prescribed for different timelines and different mechanisms of harm. Cyclobenzaprine is typically ordered for days to a few weeks alongside rest and physical therapy. Baclofen is often long-term, sometimes delivered via an intrathecal pump for severe spasticity, and stopping it is never a simple matter of missing a dose or two — the body has adapted to it in a way that makes withdrawal dangerous.
Nursing considerations before giving it
Check for other central nervous system depressants on the medication list — opioids, benzodiazepines, alcohol — before administering, since the sedative effect of a muscle relaxant compounds with anything else that slows the brain. This combination is the single biggest driver of falls and respiratory depression in patients on these drugs, and it deserves a deliberate check every time, not just at admission.
Confirm renal and hepatic function where relevant, since cyclobenzaprine is metabolised hepatically and baclofen is cleared renally, and impairment in either organ prolongs drug effect and increases toxicity risk. For a patient already on an intrathecal baclofen pump, verify the pump's programmed rate and reservoir status are documented and current before any oral dose adjustment, since abrupt gaps in either delivery route carry the same withdrawal risk.
What to monitor
Sedation level and fall risk sit at the top of every monitoring plan for this drug class. Assess orientation, gait, and grip strength before letting an ambulatory patient walk unassisted after a new dose or dose increase, and keep the call bell within reach. In an older adult, even a standard dose can produce disproportionate drowsiness, so reassess more frequently in this population.
Watch respiratory rate and level of consciousness closely if the patient is also receiving an opioid or benzodiazepine, since additive CNS depression can progress to respiratory failure. For baclofen specifically, track the degree of spasticity itself, not just sedation — worsening rigidity, new spasms, or autonomic instability (fever, tachycardia, altered mental status) can signal early withdrawal even before a dose has been technically missed, particularly in patients on an intrathecal pump with a mechanical failure.
Side effects versus adverse effects
Drowsiness, dizziness, dry mouth, and mild weakness are expected side effects across nearly every muscle relaxant and do not usually require the drug to be held, though they should be documented and factored into fall precautions. These are the effects a patient should be warned about in advance so they are not alarmed by them.
Adverse effects are a different category: respiratory depression, significant hypotension, urinary retention, or signs of hepatotoxicity with cyclobenzaprine. For baclofen, the adverse effect that defines this drug class is withdrawal syndrome — seizures, hyperthermia, rebound spasticity so severe it mimics malignant hyperthermia, and altered mental status progressing to hallucinations. These findings are not a reason to simply document and continue; they require provider notification and, often, immediate intervention.
What to hold for and when to call
Hold the dose and notify the provider for marked sedation with difficulty rousing the patient, a respiratory rate below the threshold set by facility protocol (commonly below 12 per minute), or a significant drop in blood pressure with dizziness or syncope. These findings suggest the CNS depressant load has exceeded what the patient can safely tolerate.
Call immediately, rather than simply holding the dose, if a patient on baclofen has missed several doses, has a malfunctioning intrathecal pump, or presents with new fever, tachycardia, worsening spasticity, or altered mental status. This picture points to baclofen withdrawal, which is a medical emergency and needs rapid re-establishment of the drug, not a wait-and-see approach.
Patient teaching
Teach every patient starting a muscle relaxant not to drive or operate machinery until they know how the drug affects them, and not to combine it with alcohol or other sedatives. Reinforce basic fall precautions at home — clearing walkways, using a call system if hospitalised, standing up slowly — since the sedation risk does not disappear once the patient leaves a monitored setting.
For anyone on baclofen, the teaching point that matters most is that this medication is never stopped abruptly, even if the patient feels well or wants to see if their spasticity has improved. Doses are only reduced under medical supervision, on a taper. Patients on an intrathecal pump should be taught the early warning signs of withdrawal — increasing stiffness, sweating, itching, or a fast heartbeat — and told to seek care immediately rather than waiting for a scheduled follow-up.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our pharmacology practice questions are the closest set to what this page covers.
One question from the pharmacology set
A client with heart failure is started on furosemide 40 mg PO daily. Which findings should the nurse report to the provider before administering the next dose? Select all that apply.
Rationale
Furosemide is a loop diuretic, so the two things you are watching are potassium and kidney function. A potassium of 2.9 mEq/L is below the 3.5–5.0 reference range and puts the client at risk for dysrhythmia — hold and report. Muscle cramps with palpitations are the clinical face of that same hypokalemia, so they are reported together, not separately. A creatinine that doubles signals the diuresis has outrun renal perfusion. A blood pressure of 132/78 and a 1 kg loss are the expected response to the drug working, not reasons to hold it.
Answer: A, D, E
Common questions
Can you stop baclofen suddenly if it isn't working?
No. Abrupt discontinuation of baclofen in a patient with spasticity can trigger withdrawal seizures, hallucinations, high fever, and a dangerous rebound in muscle tone. Any dose change is made gradually under medical supervision, and this applies to both oral baclofen and intrathecal pump therapy.
What is the biggest nursing concern with cyclobenzaprine?
Sedation, and the fall risk that comes with it, especially in older adults or anyone also taking opioids or benzodiazepines. Assess gait and orientation before letting a patient ambulate unassisted after a dose.
How do I tell a normal side effect from something that needs reporting?
Drowsiness, dry mouth, and mild dizziness are expected and usually just require documentation and fall precautions. Marked sedation, a slowed respiratory rate, significant hypotension, or — with baclofen — signs of withdrawal such as fever and worsening spasticity need immediate provider notification.
What are the early signs of baclofen withdrawal?
Increasing muscle stiffness or spasm, sweating, itching, a fast heart rate, and low-grade fever are early signs, which can progress to seizures, hallucinations, and severe hyperthermia if untreated. Patients on an intrathecal pump need to know these signs specifically, since a pump malfunction can cause withdrawal even when they haven't missed an oral dose.
Why do muscle relaxants matter so much for fall risk in hospital?
Nearly all muscle relaxants act on the central nervous system, producing sedation and reduced coordination that compounds with age, other medications, and an unfamiliar hospital environment. This is why gait and orientation checks before ambulation, and call bell access, are standard practice after starting or increasing a dose.
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