U.S. Department of Health & Human Services Divider Arrow National Institutes of Health Divider Arrow NCATS

Details

Stereochemistry RACEMIC
Molecular Formula C12H15NO3
Molecular Weight 221.2524
Optical Activity ( + / - )
Defined Stereocenters 0 / 1
E/Z Centers 0
Charge 0

SHOW SMILES / InChI
Structure of METAXALONE

SMILES

CC1=CC(OCC2CNC(=O)O2)=CC(C)=C1

InChI

InChIKey=IMWZZHHPURKASS-UHFFFAOYSA-N
InChI=1S/C12H15NO3/c1-8-3-9(2)5-10(4-8)15-7-11-6-13-12(14)16-11/h3-5,11H,6-7H2,1-2H3,(H,13,14)

HIDE SMILES / InChI

Molecular Formula C12H15NO3
Molecular Weight 221.2524
Charge 0
Count
Stereochemistry RACEMIC
Additional Stereochemistry No
Defined Stereocenters 0 / 1
E/Z Centers 0
Optical Activity ( + / - )

Description
Curator's Comment: description was created based on several sources, including: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=da237968-1c52-47c3-986b-4f878bd6b173 http://www.drugbank.ca/drugs/DB00660 https://en.wikipedia.org/wiki/Metaxalone

Metaxalone (marketed by King Pharmaceuticals under the brand name Skelaxin) is a muscle relaxant used to relax muscles and relieve pain caused by strains, sprains, and other musculoskeletal conditions. The mechanism of action of metaxalone in humans has not been established, but may be due to general central nervous system depression. Metaxalone has no direct action on the contractile mechanism of striated muscle, the motor end plate, or the nerve fiber. Skelaxin is available in an 800 mg scored tablet. Metaxalone relatively low incidence of side effects. The most common adverse reactions to Metaxalone tablets include drowsiness, dizziness, headache, and nervousness or “irritability”, nausea, vomiting, gastrointestinal upset.

CNS Activity

Curator's Comment: CNS depressant used for acute musculoskeletal spasmodic pain.

Originator

Curator's Comment: Metaxalone was first discovered in the 1960s, and had been sold under the brand name Skelaxin since 1962 -- first by A.H. Robins Co., then by Elan Pharma, Inc ('Elan'), and finally by King.

Approval Year

Targets

Targets

Primary TargetPharmacologyConditionPotency
Conditions

Conditions

ConditionModalityTargetsHighest PhaseProduct
Secondary
METAXALONE

Approved Use

are indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomforts associated with acute, painful musculoskeletal conditions

Launch Date

-2.20320006E11
Cmax

Cmax

ValueDoseCo-administeredAnalytePopulation
1816 ng/mL
800 mg single, oral
dose: 800 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FASTED
983 ng/mL
400 mg single, oral
dose: 400 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FASTED
1816 ng/mL
800 mg single, oral
dose: 800 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FASTED
3510 ng/mL
800 mg single, oral
dose: 800 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FED
AUC

AUC

ValueDoseCo-administeredAnalytePopulation
15044 ng × h/mL
800 mg single, oral
dose: 800 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FASTED
7479 ng × h/mL
400 mg single, oral
dose: 400 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FASTED
15045 ng × h/mL
800 mg single, oral
dose: 800 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FASTED
20833 ng × h/mL
800 mg single, oral
dose: 800 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FED
T1/2

T1/2

ValueDoseCo-administeredAnalytePopulation
8 h
800 mg single, oral
dose: 800 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FASTED
9 h
400 mg single, oral
dose: 400 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
METAXALONE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: FEMALE / MALE
food status: FASTED
Doses

Doses

DosePopulationAdverse events​
800 mg 4 times / day multiple, oral
Dose: 800 mg, 4 times / day
Route: oral
Route: multiple
Dose: 800 mg, 4 times / day
Co-administed with::
Serotonergic drugs
Sources:
unhealthy
Disc. AE: Serotonin syndrome...
AEs leading to
discontinuation/dose reduction:
Serotonin syndrome
Sources:
AEs

AEs

AESignificanceDosePopulation
Serotonin syndrome Disc. AE
800 mg 4 times / day multiple, oral
Dose: 800 mg, 4 times / day
Route: oral
Route: multiple
Dose: 800 mg, 4 times / day
Co-administed with::
Serotonergic drugs
Sources:
unhealthy
OverviewDrug as perpetrator​

Drug as perpetrator​

TargetModalityActivityMetaboliteClinical evidence
no
no
no
no
no
no
no
no
no
no
no
no
Drug as victim
Sourcing

Sourcing

Vendor/AggregatorIDURL
PubMed

PubMed

TitleDatePubMed
Polydrug fatality involving metaxalone.
2003 Mar
Auditory hallucinations elicited by combined meclizine and metaxalone use at bedtime.
2004 Nov
Quantification of metaxalone in human plasma by liquid chromatography coupled to tandem mass spectrometry.
2006 May
High throughput LC-MS/MS method for simultaneous quantification of lamivudine, stavudine and nevirapine in human plasma.
2007 Jun 15
Synthesis of poly(ethylene glycol)-metaxalone conjugates and study of its controlled release in vitro.
2007 Mar 6
Steady state bioequivalence of generic and innovator formulations of stavudine, lamivudine, and nevirapine in HIV-infected Ugandan adults.
2008
Choosing a skeletal muscle relaxant.
2008 Aug 1
HPLC-ESI-MS/MS validated method for simultaneous quantification of zopiclone and its metabolites, N-desmethyl zopiclone and zopiclone-N-oxide in human plasma.
2008 Mar 15
Development of a list of potentially inappropriate drugs for the korean elderly using the delphi method.
2010 Dec
Pediatric metaxalone ingestions reported to Texas poison control centers, 2000-2007.
2010 Jan
Pharmaceutical formulation facilities as sources of opioids and other pharmaceuticals to wastewater treatment plant effluents.
2010 Jul 1
Patents

Sample Use Guides

The recommended dose for adults and children over 12 years of age is one 800 mg tablet three to four times a day.
Route of Administration: Oral
In Vitro Use Guide
Unknown
Substance Class Chemical
Created
by admin
on Fri Dec 15 17:17:02 UTC 2023
Edited
by admin
on Fri Dec 15 17:17:02 UTC 2023
Record UNII
1NMA9J598Y
Record Status Validated (UNII)
Record Version
  • Download
Name Type Language
METAXALONE
HSDB   INN   MART.   MI   ORANGE BOOK   USAN   USP-RS   VANDF   WHO-DD  
INN   USAN  
Official Name English
SKELAXIN
Brand Name English
metaxalone [INN]
Common Name English
METAXALONE [MART.]
Common Name English
NSC-170959
Code English
METAXALONE [VANDF]
Common Name English
2-OXAZOLIDINONE, 5-((3,5-DIMETHYLPHENOXY)METHYL)-
Systematic Name English
METAXALONE [USP-RS]
Common Name English
FLEXURA
Brand Name English
METAXALONE [ORANGE BOOK]
Common Name English
Metaxalone [WHO-DD]
Common Name English
AHR-438
Code English
METAXALONE [USAN]
Common Name English
METAXALONE [MI]
Common Name English
METAXALONE [USP MONOGRAPH]
Common Name English
ZORANE
Brand Name English
5-[(3,5-Xylyloxy)methyl]-2-oxazolidinone
Systematic Name English
METAXALONE [HSDB]
Common Name English
Classification Tree Code System Code
NDF-RT N0000175730
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
LIVERTOX NBK548838
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
NDF-RT N0000175737
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
NCI_THESAURUS C29696
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
Code System Code Type Description
ECHA (EC/EINECS)
216-777-6
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
EVMPD
SUB08817MIG
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
PUBCHEM
15459
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
DRUG CENTRAL
1722
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
WIKIPEDIA
METAXALONE
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
EPA CompTox
DTXSID3023269
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
MERCK INDEX
m322
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY Merck Index
HSDB
3236
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
CAS
105801-80-7
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
SUPERSEDED
FDA UNII
1NMA9J598Y
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
CAS
1665-48-1
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
IUPHAR
7609
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
RS_ITEM_NUM
1396149
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
DAILYMED
1NMA9J598Y
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
MESH
C011301
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
INN
1027
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
ChEMBL
CHEMBL1079604
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
NSC
170959
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
RXCUI
59078
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY RxNorm
DRUG BANK
DB00660
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
SMS_ID
100000081199
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
NCI_THESAURUS
C47606
Created by admin on Fri Dec 15 17:17:02 UTC 2023 , Edited by admin on Fri Dec 15 17:17:02 UTC 2023
PRIMARY
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