Methocarbamol

Methocarbamol
Clinical data
Trade namesRobaxin, Marbaxin, others
AHFS/Drugs.comMonograph
MedlinePlusa682579
License data
Pregnancy
category
  • AU: B2
Routes of
administration		By mouth, intravenous
ATC code
Legal status
Legal status
Pharmacokinetic data
MetabolismLiver
Elimination half-life1.14–1.24 hours[2]
Identifiers
  • (RS)-2-hydroxy-3-(2-methoxyphenoxy)propyl carbamate
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.007.751 Edit this at Wikidata
Chemical and physical data
FormulaC11H15NO5
Molar mass241.243 g·mol−1
3D model (JSmol)
  • O=C(OCC(O)COc1ccccc1OC)N
  • InChI=1S/C11H15NO5/c1-15-9-4-2-3-5-10(9)16-6-8(13)7-17-11(12)14/h2-5,8,13H,6-7H2,1H3,(H2,12,14) checkY
  • Key:GNXFOGHNGIVQEH-UHFFFAOYSA-N checkY
 ☒NcheckY (what is this?)  (verify)

Methocarbamol, sold under the brand name Robaxin among others, is a medication used for short-term musculoskeletal pain.[3][4] It may be used together with rest, physical therapy, and pain medication.[3][5][6] It is less preferred in low back pain.[3] It has limited use for rheumatoid arthritis and cerebral palsy.[3][7] Effects generally begin within half an hour.[3] It is taken by mouth or injection into a vein.[3]

Common side effect include headaches, sleepiness, and dizziness.[3][8] Serious side effects may include anaphylaxis, liver problems, confusion, and seizures.[4] Use is not recommended in pregnancy and breastfeeding.[3][4] Because of risk of injury, skeletal muscle relaxants should generally be avoided in geriatric patients.[3] Methocarbamol is a centrally acting muscle relaxant.[3] How it works is unclear, but it does not appear to affect muscles directly.[3]

Methocarbamol was developed in 1956 in the laboratories of A. H. Robins (later acquired by Pfizer). Studies were directed towards the development of propanediol derivatives which possessed muscle relaxant properties superior to those of mephenesin, which had low potency and a short duration of action.[9] It was approved for medical use in the United States in 1957.[3] It is available as a generic medication.[3][4] In 2022, it was the 126th most commonly prescribed medication in the United States, with more than 5 million prescriptions.[10][11]

  1. ^ "Robaxin-750 - Summary of Product Characteristics (SmPC)". (emc). 8 August 2017. Retrieved 19 April 2020.
  2. ^ Sica DA, Comstock TJ, Davis J, Manning L, Powell R, Melikian A, et al. (1990). "Pharmacokinetics and protein binding of methocarbamol in renal insufficiency and normals". European Journal of Clinical Pharmacology. 39 (2): 193–194. doi:10.1007/BF00280060. PMID 2253675. S2CID 626920.
  3. ^ a b c d e f g h i j k l m "Methocarbamol Monograph for Professionals". Drugs.com. American Society of Health-System Pharmacists.
  4. ^ a b c d British national formulary : BNF 76 (76 ed.). Pharmaceutical Press. 2018. p. 1093. ISBN 9780857113382.
  5. ^ "Robaxin- methocarbamol tablet, film coated". DailyMed. 18 July 2019. Retrieved 19 April 2020.
  6. ^ "Robaxin- methocarbamol injection". DailyMed. 10 December 2018. Retrieved 19 April 2020.
  7. ^ Richards BL, Whittle SL, Buchbinder R (January 2012). "Muscle relaxants for pain management in rheumatoid arthritis". The Cochrane Database of Systematic Reviews. 1: CD008922. doi:10.1002/14651858.CD008922.pub2. PMID 22258993. S2CID 73769165.
  8. ^ "Methocarbamol". LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. National Institute of Diabetes and Digestive and Kidney Diseases. 30 January 2017. PMID 31643609.
  9. ^ Analytical Profiles of Drug Substances and Excipients, pp. 373
  10. ^ "The Top 300 of 2022". ClinCalc. Archived from the original on 30 August 2024. Retrieved 30 August 2024.
  11. ^ "Methocarbamol Drug Usage Statistics, United States, 2013 - 2022". ClinCalc. Retrieved 30 August 2024.