Cyclobenzaprine

Mechanism-of-action classes: Monoamine Oxidase Inhibitors; Unknown Cellular or Molecular Interaction.

• Cyclobenzaprine hydrochloride tablets, USP are indicated as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions. Improvement is manifested by relief of muscle spasm and its associated signs and symptoms, namely, pain, tenderness, limitation of motion, and restriction in activities of daily living.

• Hypersensitivity to any component of this product. Concomitant use of monoamine oxidase (MAO) inhibitors or within 14 days after their discontinuation.contraindicated

For most patients, the recommended dose of cyclobenzaprine hydrochloride tablets is 5 mg three times a day. Based on individual patient response, the dose may be increased to 10 mg three times a day. Use of cyclobenzaprine hydrochloride tablets for periods longer than 2 or 3 weeks is not recommended (see INDICATIONS AND USAGE) . Less frequent dosing should be considered for hepatically impaired or elderly patients (see PRECAUTIONS: Impaired Hepatic Function , and Use in the Elderly).

Serotonin Syndrome The development of a potentially life-threatening serotonin syndrome has been reported with cyclobenzaprine hydrochloride when used in combination with other drugs, such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), tramadol, bupropion, meperidine, verapamil, or (MAO) inhibitors. The concomitant use of cyclobenzaprine hydrochloride with MAO inhibitors is contraindicated (see CONTRAINDICATIONS ). Serotonin syndrome symptoms may include mental status changes (e.g., confusion, agitation, hallucinations), autonomic instability (e.g., diaphoresis, tachycardia, labile blood pressure, hyperthermia), neuromuscular abnormalities (e.g., tremor, ataxia, hyperreflexia, clonus, muscle rigidity), and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). Treatment with cyclobenzaprine hydrochloride and any concomitant serotonergic agents should be discontinued immediately if the above reactions occur and supportive symptomatic treatment should be initiated. If concomitant treatment with cyclobenzaprine hydrochloride and other serotonergic drugs is clinically warranted, careful observation is advised, particularly during treatment initiation or dose increases (see PRECAUTIONS: Drug Interactions ). Cyclobenzaprine is closely related to the tricyclic antidepressants, e.g., amitriptyline and imipramine.

Incidence of most common adverse reactions in the two double-blind*, placebo-controlled 5 mg studies (incidence of > 3% on cyclobenzaprine hydrochloride 5 mg): Cyclobenzaprine Hydrochloride 5 mg Cyclobenzaprine Hydrochloride 10 mg Placebo N = 464 N = 249 N = 469 Drowsiness 29% 38% 10% Dry Mouth 21% 32% 7% Fatigue 6% 6% 3% Headache 5% 5% 8% *Note: Cyclobenzaprine hydrochloride 10 mg data are from one clinical trial. Cyclobenzaprine hydrochloride 5 mg and placebo data are from two studies. Adverse reactions which were reported in 1% to 3% of the patients were: abdominal pain, acid regurgitation, constipation, diarrhea, dizziness, nausea, irritability, mental acuity decreased, nervousness, upper respiratory infection, and pharyngitis. The following list of adverse reactions is based on the experience in 473 patients treated with cyclobenzaprine hydrochloride 10 mg in additional controlled clinical studies, 7,607 patients in the postmarketing surveillance program, and reports received since the drug was marketed. The overall incidence of adverse reactions among patients in the surveillance program was less than the incidence in the controlled clinical studies. The adverse reactions reported most frequently with cyclobenzaprine were drowsiness, dry mouth and dizziness.

Although rare, deaths may occur from overdosage with cyclobenzaprine. Multiple drug ingestion (including alcohol) is common in deliberate cyclobenzaprine overdose. As management of overdose is complex and changing, it is recommended that the physician contact a poison control center for current information on treatment . Signs and symptoms of toxicity may develop rapidly after cyclobenzaprine overdose; therefore, hospital monitoring is required as soon as possible. The acute oral LD 50 of cyclobenzaprine is approximately 338 and 425 mg/kg in mice and rats, respectively. Manifestations The most common effects associated with cyclobenzaprine overdose are drowsiness and tachycardia. Less frequent manifestations include tremor, agitation, coma, ataxia, hypertension, slurred speech, confusion, dizziness, nausea, vomiting, and hallucinations. Rare but potentially critical manifestations of overdose are cardiac arrest, chest pain, cardiac dysrhythmias, severe hypotension, seizures, and neuroleptic malignant syndrome. Changes in the electrocardiogram, particularly in QRS axis or width, are clinically significant indicators of cyclobenzaprine toxicity.

• Feb 29, 1988ANDAANDA071611Actavis Labs Fl Inc
• Apr 19, 2006ANDAANDA077563Jubilant Cadista
• Feb 1, 2007NDANDA021777Teva Pharms Intl
• Feb 28, 2007ANDAANDA077797Prinston Inc
• Apr 18, 2008ANDAANDA078218Chartwell Rx
• May 12, 2008ANDAANDA078722Sun Pharm Inds Ltd
• Sep 26, 2008ANDAANDA078643Aurobindo Pharma
• Aug 15, 2025NDANDA219428Tonix

1. 1Pain5,02010%
2. 2Fatigue3,9538.0%
3. 3Drug Ineffective3,5597.2%
4. 4Nausea3,4407.0%
5. 5Headache3,4187.0%
6. 6Off Label Use2,8595.8%
7. 7Chronic Kidney Disease2,7675.6%
8. 8Diarrhoea2,5455.2%
9. 9Fall2,4064.9%
10. 10Arthralgia2,3994.9%
11. 11Toxicity To Various Agents2,3304.7%
12. 12Dyspnoea2,1834.4%
13. 13Constipation2,1304.3%
14. 14Back Pain2,1104.3%
15. 15Dizziness2,0304.1%

The 10 most recently updated of 61 ClinicalTrials.gov registrations naming Cyclobenzaprine as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• A Study to Evaluate TNX-102 SL Monotherapy Versus Placebo in Participants With Major Depressive Disorder (MDD)
  Recruiting · Phase 2 · Interventional · 360 enrolled · Tonix Pharmaceuticals, Inc.
  NCT07621237updated 2026-06-02
• Multimodal Analgesia vs. Routine Care Pain Management for Lumbar Spine Fusion Surgery: A Prospective Randomized Study
  Terminated · Phase 4 · Interventional · 50 enrolled · OrthoCarolina Research Institute, Inc.
  NCT02202369updated 2026-05-22
• Pharmacokinetics and Safety of Commonly Used Drugs in Lactating Women and Breastfed Infants
  Recruiting · Observational · 1,600 enrolled · Duke University
  NCT03511118updated 2026-04-24
• Prevention/Reduction of ASRs and PTSD to Sustain Civilian Performance With Sublingual Cyclobenzaprine HCl (TNX-102 SL)
  Recruiting · Phase 2 · Interventional · 180 enrolled · University of North Carolina, Chapel Hill
  NCT06636786updated 2026-04-13
• A Single-Dose, Randomized, Open-Label, 2-Way Crossover Study to Evaluate the Dose-Proportionality, Safety, and Tolerability of TNX-102 SL (Cyclobenzaprine HCl Sublingual Tablets) in Healthy Japanese and Chinese Subjects
  Completed · Phase 1 · Interventional · 20 enrolled · Tonix Pharmaceuticals, Inc.
  NCT07464535updated 2026-03-11
• Comparing Adjuvant Treatments for High Tone Pelvic Floor Dysfunction
  Recruiting · Phase 2 · Phase 3 · Interventional · 60 enrolled · University of Michigan
  NCT07404397updated 2026-02-20
• A Phase 1, Open-Label, Parallel-Group, Single-Dose Study To Compare The Pharmakokinetics Of TNX-102 SL (Cyclobenzaprine Hydrochloride Sublingual Tablet) In Non-Elderly Versus Elderly Participants
  Active not recruiting · Phase 1 · Interventional · 50 enrolled · Tonix Pharmaceuticals, Inc.
  NCT07413367updated 2026-02-17
• Multimodal Analgesia Effect on Post Surgical Patient
  Active not recruiting · Phase 4 · Interventional · 60 enrolled · University of California, Davis
  NCT04240626updated 2025-08-08
• A Comparative Study of EMG Biofeedback and Pharmacotherapy for the Treatment of Masticatory Muscle Hyperactivity in Bruxism Patients
  Not yet recruiting · Interventional · 30 enrolled · Beni-Suef University
  NCT06894472updated 2025-03-25
• Repeat of: A Study to Evaluate Efficacy and Safety of Sublingual TNX-102 SL Tablet Taken at Bedtime in Patients With Fibromyalgia
  Terminated · Phase 3 · Interventional · 51 enrolled · Tonix Pharmaceuticals, Inc.
  NCT02829814updated 2025-02-25

Ranked by 2D fingerprint (Tanimoto) similarity over PubChem structures. Structural proximity only — not a claim of therapeutic equivalence.

• AmitriptylineTricyclic Antidepressant84%

Frequently asked questions

How does Cyclobenzaprine work?

Mechanism-of-action classes: Monoamine Oxidase Inhibitors; Unknown Cellular or Molecular Interaction.

What is Cyclobenzaprine used for?

According to FDA labeling, Cyclobenzaprine carries indications including: Cyclobenzaprine hydrochloride tablets, USP are indicated as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions. Improvement is manifested by relief of muscle spasm and its associated signs and symptoms, namely, pain, tenderness, limitation of motion, and restriction in activities of daily living.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Cyclobenzaprine?

Cyclobenzaprine is classified as Other centrally acting agents, Muscle Relaxant, Monoamine Oxidase Inhibitors, Unknown Cellular or Molecular Interaction, Centrally-mediated Muscle Relaxation, Decreased Central Nervous System Organized Electrical Activity, Striated Muscle Metabolic Alteration.

What are the brand names for Cyclobenzaprine?

Cyclobenzaprine is marketed under brand names including Amrix, Fexmid, Tonmya.

What are the contraindications for Cyclobenzaprine?

Cyclobenzaprine labeling lists contraindications including: Hypersensitivity to any component of this product. Concomitant use of monoamine oxidase (MAO) inhibitors or within 14 days after their discontinuation.. Always consult the full prescribing information and a clinician.