Cyclobenzaprine
Cyclobenzaprine is a centrally-acting muscle relaxant used for short-term relief of painful musculoskeletal conditions involving muscle spasms. It works by reducing muscle hyperactivity through its effects on the brainstem and spinal cord. This medication is typically prescribed alongside rest, physical therapy, and other treatments for conditions such as back pain, neck pain, and fibrositis.
A short-term muscle relaxant used to relieve muscle spasms associated with acute musculoskeletal pain.
Key facts at a glance
- ATC
- M03BX08
- RxNorm
- 21949
- Generic
- Cyclobenzaprine
- Class
- atc-m03
- Brands
- Tonmya, Fexmid, Amrix
- Availability
- rx
- Lactation
- unknown
- Routes
- oral, sublingual
- Forms
- capsule, tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
8 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second third trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring and uterine activity
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingdiscontinue breastfeeding or avoid drug
cyclobenzaprine is excreted in breast milk; avoid use while breastfeeding
monitor infant for excessive drowsiness
Use of this medication in this population requires careful consideration of risks and benefits.
geriatric
elderlyreduce dose and increase interval
use lower starting dose (5mg); monitor for sedation, dizziness, and anticholinergic effects
regular assessment of cognitive function and fall risk
Use with caution and monitor for adverse effects.
pediatric_age
adolescents 15 18standard adult dosing
use with caution; not recommended for prolonged use
monitor for adverse effects
Use with caution and monitor for adverse effects.
pediatric_age
children under 15not recommended
not recommended for children under 15 years of age
not applicable
Use of this medication in this population requires careful consideration of risks and benefits.
renal_impairment
severe renal impairmentreduce dose or increase dosing interval
use with caution; may require dose reduction in severe impairment
monitor renal function and drug accumulation
Use with caution and monitor for adverse effects.
hepatic_impairment
severe hepatic impairmentavoid use
avoid in severe hepatic impairment due to extensive hepatic metabolism
liver function tests
Use of this medication in this population requires careful consideration of risks and benefits.
Statistics and clinical data
Drug class
Cyclobenzaprine is classified as a centrally acting muscle relaxant
Common uses
Primary therapeutic indication
FDA approval year
Initial FDA approval date for cyclobenzaprine
Mechanism of action
Pharmacological mechanism
Cyclobenzaprine is used to treat acute musculoskeletal conditions with muscle spasms, including back pain, neck pain, and other traumatic or inflammatory conditions. It is typically prescribed as part of a comprehensive treatment plan that includes rest, physical therapy, and other measures.
Cyclobenzaprine acts on the central nervous system, primarily in the brainstem, to reduce tonic somatic motor activity. While its exact mechanism is not fully understood, it is structurally related to tricyclic antidepressants and appears to inhibit ascending pain pathways and reduce muscle hyperactivity.
This medication is intended for short-term use (typically 2-3 weeks maximum) as prolonged use has not been studied. Common side effects include drowsiness, dry mouth, and dizziness. It should not be used in patients with hyperthyroidism, heart failure, arrhythmias, recent myocardial infarction, or those taking MAO inhibitors. Patients should avoid operating machinery or driving until they know how the medication affects them.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 24, 2026. · Read our editorial policy