A centrally acting skeletal muscle relaxant structurally related to tricyclic antidepressants, used for the short-term relief of muscle spasm associated with acute, painful musculoskeletal conditions. Cyclobenzaprine is most effective when used in conjunction with rest and physical therapy. It is not effective for spasticity from upper motor neuron disorders.
Concurrent use of MAO inhibitors or within 14 days
The bottom line
Evidence rating strong. Most-documented uses: short-term relief of acute muscle spasm, improved sleep quality in patients with muscle pain, adjunct to rest and physical therapy. 10 sources indexed (2020–2026), with 1 interaction record on file.
The science
How it works, mechanistically.
Core mechanism
Acts primarily within the brainstem to reduce tonic somatic motor activity by influencing both gamma and alpha motor neurons. It reduces muscle hyperactivity without directly acting on skeletal muscle, the neuromuscular junction, or the spinal cord. The exact mechanism is not fully understood, but it may involve effects on descending serotonergic pathways in the brainstem reticular formation.
Class
Skeletal Muscle Relaxant
Dosing
Dosing & protocol.
Common range
5–10 mg three times daily; recommended for short-term use (2–3 weeks) (as prescribed by your physician)
Recommended form
Tablet or extended-release capsule
Can be taken with or without food; may cause significant drowsiness, take at bedtime if sedation is bothersome
Cyclobenzaprine commonly causes drowsiness, dizziness, and slowed reaction time, and alcohol can intensify those effects. Combining them can increase falls, accidents, impaired driving, confusion, and overdose risk. Older adults are especially vulnerable because skeletal muscle relaxants are poorly tolerated in that group.
Recommendation: Avoid alcohol while taking cyclobenzaprine. If alcohol was used, do not drive, operate tools, or take extra sedatives that day. Contact your prescriber if you need muscle spasm treatment but cannot reliably avoid alcohol.
Al-Qudah AA, Al-Hanaktah M. Short-term efficacy and safety of sublingual cyclobenzaprine for fibromyalgia: A systematic review and meta-analysis. Clinical rheumatology. 2026
Lederman S, Arnold LM, Vaughn B et al.. Pain relief by targeting nonrestorative sleep in fibromyalgia: a phase 3 randomized trial of bedtime sublingual cyclobenzaprine. Pain medicine (Malden, Mass.). 2026
Parmenter ME, Lederman S, Weathers FW et al.. A phase 3, randomized, placebo-controlled, trial to evaluate the efficacy and safety of bedtime sublingual cyclobenzaprine (TNX-102 SL) in military-related posttraumatic stress disorder. Psychiatry research. 2024
Caron J, Kaye R, Wessel T et al.. An assessment of the centrally acting muscle relaxant tolperisone on driving ability and cognitive effects compared to placebo and cyclobenzaprine. Journal of clinical pharmacy and therapeutics. 2020
Tu J, Zhang C, Xie S et al.. Cyclobenzaprine-related adverse events: a comprehensive pharmacovigilance analysis using the FDA Adverse Event Reporting System. Frontiers in medicine. 2025
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