Description

Simple

A muscle relaxant used to treat muscle spasms.

Clinical

A skeletal muscle relaxant that works on the brainstem to treat muscle spasms of local origin.

Overview

Cyclobenzaprine, a centrally-acting muscle relaxant, was first synthesized in 1961[11] and has been available for human use since 1977.[10] It was initially studied for use as antidepressant given its structural similarity to tricyclic antidepressants - it differs from [Amitriptyline] by only a single double bond.[11,10] Since its approval, it has remained relatively popular as an adjunctive, short-term treatment for acute skeletal muscle spasms secondary to musculoskeletal injury.

Pharmacology

Indication

Cyclobenzaprine is indicated as a short-term (2-3 weeks) adjunct therapy, along with rest and physical therapy, for relief of muscle spasm associated with acute, painful musculoskeletal conditions. It has not been found effective in the treatment of spasticity originating from cerebral or spinal cor... Read more

Pharmacodynamic

Cyclobenzaprine is a skeletal muscle relaxant that works on areas of the brainstem to reduce skeletal muscle spasm, though its exact pharmacodynamic behaviour is currently unclear.[15, Read more

Mechanism of action

The exact mechanism of action of cyclobenzaprine has not been fully elucidated in humans, and much of the information available regarding its mechanism has been ascertained from early animal studies. There is some evidence that cyclobenzaprine exerts its effects at the supraspinal level, specificall... Read more

Absorption

The oral bioavailability of cyclobenzaprine has been estimated to be between 0.33 and 0.55.[ Read more

Protein binding

Cyclobenzaprine is approximately 93% protein bound in plasma.[ Read more

Volume of distribution

The volume of distribution of cyclobenzaprine is approximately 146 L.[ Read more

Clearance

The approximate plasma clearance of cyclobenzaprine is 0.7 L/min.[ Read more

Half life

The effective half-life of cyclobenzaprine in young healthy subjects is approximately 18 hours.[ Read more

Route of elimination

After administration of a radio-labeled dose of cyclobenzaprine, 38-51% of radioactivity was excreted in the urine while 14-15% was excreted in the feces.[16] Cyclobenzaprine is highly metabolized, with... Read more

Toxicity

The oral LD50 of cyclobenzaprine in mice and rats is 338 mg/kg and 425 mg/kg, respectively. Signs of overdose may develop rapidly after ingestion and commonly include significant drowsiness and tachycardia, with less common manifestations including tremor, agitation, ataxia, GI upset, and... Read more

Adverse Effects

Contraindications

  • Route:
    • Oral
  • Hypersensitivity:
    • true
  • Regions: US
  • Route:
    • Oral
  • Time Period: During MAO-I therapy or within 14 days after their discontinuation
  • Regions: US
  • With Categories Coadmin:
      • Name: Monoamine Oxidase Inhibitors
      • Drugbank Id: DBCAT001004
      • Mesh Id: D008996
  • Route:
    • Oral
  • Regions: US
  • Patient Conditions:
      • Name: Arrhythmias
      • Drugbank Id: DBCOND0031410
  • Route:
    • Oral
  • Regions: US
  • Patient Conditions:
      • Name: Acute recovery phase of myocardial infarction
      • Drugbank Id: DBCOND0107607
  • Route:
    • Oral
  • Regions: US
  • Patient Conditions:
      • Name: Conduction Disturbances
      • Drugbank Id: DBCOND0071211
  • Route:
    • Oral
  • Regions: US
  • Patient Conditions:
      • Name: Heart Block
      • Drugbank Id: DBCOND0032425
  • Route:
    • Oral
  • Regions: US
  • Patient Conditions:
      • Name: Hyperthyroidism
      • Drugbank Id: DBCOND0009048
  • Route:
    • Oral
  • Regions: US
  • Patient Conditions:
      • Name: Congestive Heart Failure
      • Drugbank Id: DBCOND0029751

Food Interactions

  • Avoid alcohol.
  • Take with food to reduce irritation.

Interactions

Type in a drug name to check for interaction with Cyclobenzaprine
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  • Paracetamol(acetaminophen)
  • Paxil(paroxetine)
  • Pamelor(nortriptyline)
  • Panadol(acetaminophen)
  • Patanol(olopatadine ophthalmic)
  • Pataday(olopatadine ophthalmic)
  • Parnate(tranylcypromine)
  • Pazeo(olopatadine ophthalmic)
2,4-thiazolidinedione
Cyclobenzaprine may decrease the hypoglycemic activities of 2,4-thiazolidinedione.
2,5-Dimethoxy-4-ethylthioamphetamine
The risk or severity of CNS depression can be increased when 2,5-Dimethoxy-4-ethylthioamphetamine is combined with Cyclobenzaprine.
4-Bromo-2,5-dimethoxyamphetamine
The risk or severity of CNS depression can be increased when 4-Bromo-2,5-dimethoxyamphetamine is combined with Cyclobenzaprine.
4-Bromo-2,5-dimethoxyphenethylamine
The risk or severity of hypertension can be increased when Cyclobenzaprine is combined with 4-Bromo-2,5-dimethoxyphenethylamine.
4-Methoxyamphetamine
The risk or severity of CNS depression can be increased when Cyclobenzaprine is combined with 4-Methoxyamphetamine.
5-methoxy-N,N-dimethyltryptamine
The risk or severity of CNS depression can be increased when Cyclobenzaprine is combined with 5-methoxy-N,N-dimethyltryptamine.
6-Deoxyerythronolide B
The metabolism of Cyclobenzaprine can be decreased when combined with 6-Deoxyerythronolide B.
7-ethyl-10-hydroxycamptothecin
The metabolism of Cyclobenzaprine can be decreased when combined with 7-ethyl-10-hydroxycamptothecin.
7-Nitroindazole
The risk or severity of CNS depression can be increased when Cyclobenzaprine is combined with 7-Nitroindazole.
7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline
Cyclobenzaprine may increase the serotonergic activities of 7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline.
8-azaguanine
The metabolism of 8-azaguanine can be decreased when combined with Cyclobenzaprine.
8-chlorotheophylline
The metabolism of 8-chlorotheophylline can be decreased when combined with Cyclobenzaprine.
9-aminocamptothecin
The metabolism of Cyclobenzaprine can be decreased when combined with 9-aminocamptothecin.
9-Deazaguanine
The metabolism of 9-Deazaguanine can be decreased when combined with Cyclobenzaprine.
9-Methylguanine
The metabolism of 9-Methylguanine can be decreased when combined with Cyclobenzaprine.
Abatacept
The metabolism of Cyclobenzaprine can be increased when combined with Abatacept.
Abediterol
The risk or severity of hypertension can be increased when Cyclobenzaprine is combined with Abediterol.
Abiraterone
The serum concentration of Cyclobenzaprine can be increased when it is combined with Abiraterone.
Acalabrutinib
The metabolism of Cyclobenzaprine can be decreased when combined with Acalabrutinib.
Acarbose
Cyclobenzaprine may decrease the hypoglycemic activities of Acarbose.
16 References
  1. 1 . Wang RW, Liu L, Cheng H: Identification of human liver cytochrome P450 isoforms involved in the in vitro metabolism of cyclobenzaprine. Drug Metab Dispos. 1996 Jul;24(7):786-91.PubMed: 8818577
  2. 2 . Lu D, Xie Q, Wu B: N-glucuronidation catalyzed by UGT1A4 and UGT2B10 in human liver microsomes: Assay optimization and substrate identification. J Pharm Biomed Anal. 2017 Oct 25;145:692-703. doi: 10.1016/j.jpba.2017.07.037. Epub 2017 Aug 4.PubMed: 28803208
  3. 3 . Kobayashi H, Hasegawa Y, Ono H: Cyclobenzaprine, a centrally acting muscle relaxant, acts on descending serotonergic systems. Eur J Pharmacol. 1996 Sep 5;311(1):29-35.PubMed: 8884233
  4. 4 . Honda M, Nishida T, Ono H: Tricyclic analogs cyclobenzaprine, amitriptyline and cyproheptadine inhibit the spinal reflex transmission through 5-HT(2) receptors. Eur J Pharmacol. 2003 Jan 1;458(1-2):91-9.PubMed: 12498911
  5. 5 . Mestres J, Seifert SA, Oprea TI: Linking pharmacology to clinical reports: cyclobenzaprine and its possible association with serotonin syndrome. Clin Pharmacol Ther. 2011 Nov;90(5):662-5. doi: 10.1038/clpt.2011.177. Epub 2011 Oct 5.PubMed: 21975349
  6. 6 . Hutchinson MR, Loram LC, Zhang Y, Shridhar M, Rezvani N, Berkelhammer D, Phipps S, Foster PS, Landgraf K, Falke JJ, Rice KC, Maier SF, Yin H, Watkins LR: Evidence that tricyclic small molecules may possess toll-like receptor and myeloid differentiation protein 2 activity. Neuroscience. 2010 Jun 30;168(2):551-63. doi: 10.1016/j.neuroscience.2010.03.067. Epub 2010 Apr 8.PubMed: 20381591
  7. 7 . Obach RS, Huynh P, Allen MC, Beedham C: Human liver aldehyde oxidase: inhibition by 239 drugs. J Clin Pharmacol. 2004 Jan;44(1):7-19.PubMed: 14681337
  8. 8 . Winchell GA, King JD, Chavez-Eng CM, Constanzer ML, Korn SH: Cyclobenzaprine pharmacokinetics, including the effects of age, gender, and hepatic insufficiency. J Clin Pharmacol. 2002 Jan;42(1):61-9. doi: 10.1177/0091270002042001007.PubMed: 11808825
  9. 9 . Calandre EP, Rico-Villademoros F, Slim M: An update on pharmacotherapy for the treatment of fibromyalgia. Expert Opin Pharmacother. 2015 Jun;16(9):1347-68. doi: 10.1517/14656566.2015.1047343.PubMed: 26001183
  10. 10 . Cimolai N: Cyclobenzaprine: a new look at an old pharmacological agent. Expert Rev Clin Pharmacol. 2009 May;2(3):255-63. doi: 10.1586/ecp.09.5.PubMed: 24410704
  11. 11 . Brioschi TM, Schramm SG, Kano EK, Koono EE, Ching TH, Serra CH, Porta V: Pharmacokinetics and bioequivalence evaluation of cyclobenzaprine tablets. Biomed Res Int. 2013;2013:281392. doi: 10.1155/2013/281392. Epub 2013 Sep 16.PubMed: 24151591
  12. 12 . Baig MH, Rahman S, Rabbani G, Imran M, Ahmad K, Choi I: Multi-Spectroscopic Characterization of Human Serum Albumin Binding with Cyclobenzaprine Hydrochloride: Insights from Biophysical and In Silico Approaches. Int J Mol Sci. 2019 Feb 3;20(3). pii: ijms20030662. doi: 10.3390/ijms20030662.PubMed: 30717459
  13. 13 . Hucker HB, Stauffer SC, Balletto AJ, White SD, Zacchei AG, Arison BH: Physiological disposition and metabolism of cyclobenzaprine in the rat, dog, rhesus monkey, and man. Drug Metab Dispos. 1978 Nov-Dec;6(6):659-72.PubMed: 33029
  14. 14 . CaymenChem: Cyclobenzaprine hydrochloride MSDS Link
  15. 15 . FDA Approved Drugs: Cyclobenzaprine Link
  16. 16 . DPD Approved Drugs: Cyclobenzaprine Link