metaxalone 🐶 Veterinary Use | Indications/Contra | FAERs-F | FAERs-M | Orange Bk | BioActivity |

Stem definition	Drug id	CAS RN
	1722	1665-48-1

Description:

Molecule	Description
Molfile Inchi Smiles Synonyms: metaxalone metaxalon metazalone metazolone skelaxin zorane AHR 438	muscle spasm relaxant; structure Molecular weight: 221.26 Formula: C12H15NO3 CLOGP: 2.15 LIPINSKI: 0 HAC: 4 HDO: 1 TPSA: 47.56 ALOGS: -2.24 ROTB: 3 Status: OFP Legend: OFP - off patent OFM - off market ONP - on patent

Molecule

Description

Molfile Inchi Smiles

Synonyms:

metaxalone
metaxalon
metazalone
metazolone
skelaxin
zorane
AHR 438

muscle spasm relaxant; structure

Molecular weight: 221.26
Formula: C12H15NO3
CLOGP: 2.15
LIPINSKI: 0
HAC: 4
HDO: 1
TPSA: 47.56
ALOGS: -2.24
ROTB: 3

Status: OFP

Legend:
OFP - off patent
OFM - off market
ONP - on patent

Drug dosage:

None

ADMET properties:

Property	Value	Reference
BDDCS (Biopharmaceutical Drug Disposition Classification System)	2	Benet LZ, Broccatelli F, Oprea TI
S (Water solubility)	0.30 mg/mL	Benet LZ, Broccatelli F, Oprea TI
EoM (Fraction excreted unchanged in urine)	2 %	Benet LZ, Broccatelli F, Oprea TI
MRTD (Maximum Recommended Therapeutic Daily Dose)	206.61 µM/kg/day	Contrera JF, Matthews EJ, Kruhlak NL, Benz RD

Approvals:

Date	Agency	Company	Orphan
Aug. 13, 1962	FDA	KING PHARMS

FDA Adverse Event Reporting System (Female)

MedDRA adverse event term	Likelihood ratio	Likelihood ratio threshold	Patients taking drug having adverse event	Patients taking drug not having adverse event	Patients not taking drug having adverse event	Patients not taking drug not having adverse event
Accidental death	242.73	14.31	59	11435	1917	63475611
Completed suicide	226.79	14.31	197	11297	145476	63332052
Drug hypersensitivity	185.37	14.31	253	11241	310434	63167094
Toxicity to various agents	170.02	14.31	216	11278	247034	63230494
Serotonin syndrome	61.81	14.31	47	11447	28635	63448893
Deep vein thrombosis	43.40	14.31	64	11430	83736	63393792
Anxiety	40.54	14.31	108	11386	217433	63260095
Overdose	38.24	14.31	72	11422	115006	63362522
Depression	38.08	14.31	99	11395	196393	63281135
Purpura senile	35.97	14.31	10	11484	553	63476975
Clonus	34.99	14.31	17	11477	4619	63472909
Tarsal tunnel syndrome	31.26	14.31	9	11485	565	63476963
Drug ineffective	27.07	14.31	98	11396	1044667	62432861
Off label use	26.80	14.31	51	11443	674411	62803117
Injury	25.78	14.31	47	11447	73200	63404328
Ankle fracture	25.38	14.31	23	11471	17832	63459696
Intervertebral disc protrusion	25.15	14.31	26	11468	23683	63453845
Muscle rigidity	25.11	14.31	19	11475	11481	63466047
Foot fracture	24.96	14.31	26	11468	23888	63453640
Resorption bone increased	24.21	14.31	9	11485	1265	63476263
Neck pain	23.79	14.31	44	11450	69274	63408254
Autonomic nervous system imbalance	23.30	14.31	11	11483	2807	63474721
Vestibular disorder	23.19	14.31	9	11485	1422	63476106
Infusion related reaction	22.79	14.31	8	11486	245513	63232015
Suicidal behaviour	20.89	14.31	10	11484	2629	63474899
Fibromyalgia	20.38	14.31	45	11449	80375	63397153
Vertigo positional	20.17	14.31	10	11484	2839	63474689
Joint swelling	19.93	14.31	18	11476	327648	63149880
Migraine	19.91	14.31	52	11442	103294	63374234
Treatment failure	19.32	14.31	6	11488	199037	63278491
Drug withdrawal syndrome	18.96	14.31	24	11470	27170	63450358
Respiratory arrest	18.45	14.31	26	11468	32619	63444909
Muscle spasms	18.29	14.31	66	11428	156084	63321444
Product use issue	17.56	14.31	9	11485	220511	63257017
Synovitis	17.49	14.31	6	11488	186912	63290616
Neutropenia	17.48	14.31	5	11489	175000	63302528
Systemic lupus erythematosus	17.43	14.31	8	11486	208910	63268618
Concussion	17.42	14.31	14	11480	9230	63468298
Spinal stenosis	16.98	14.31	17	11477	14908	63462620
Myocardial infarction	16.98	14.31	48	11446	99845	63377683
Temporomandibular joint syndrome	16.78	14.31	10	11484	4079	63473449
Drug abuse	16.62	14.31	39	11455	72479	63405049
Drug intolerance	16.44	14.31	19	11475	308642	63168886
Mydriasis	16.21	14.31	15	11479	11941	63465587
Coronary artery disease	15.71	14.31	24	11470	32353	63445175
Alopecia	15.70	14.31	23	11471	337513	63140015
Cerebrovascular accident	14.69	14.31	48	11446	107976	63369552
Respiratory depression	14.47	14.31	15	11479	13700	63463828
Fear	14.44	14.31	16	11478	15750	63461778

FDA Adverse Event Reporting System (Male)

MedDRA adverse event term	Likelihood ratio	Likelihood ratio threshold	Patients taking drug having adverse event	Patients taking drug not having adverse event	Patients not taking drug having adverse event	Patients not taking drug not having adverse event
Completed suicide	91.13	19.93	75	3256	98093	34855507
Toxicity to various agents	87.36	19.93	101	3230	200261	34753339
Accidental death	64.83	19.93	19	3312	2437	34951163
Drug hypersensitivity	46.09	19.93	47	3284	80482	34873118
Coronary artery disease	38.72	19.93	34	3297	48271	34905329
Back pain	26.40	19.93	44	3287	121745	34831855
Overdose	25.46	19.93	37	3294	91022	34862578
Drug withdrawal syndrome	24.50	19.93	18	3313	19816	34933784
Depression	23.65	19.93	37	3294	97061	34856539
Body height decreased	23.45	19.93	10	3321	3833	34949767
Back injury	22.97	19.93	10	3321	4031	34949569
Cerebral vasoconstriction	21.74	19.93	5	3326	246	34953354
Emotional distress	21.70	19.93	15	3316	15011	34938589
Myocardial infarction	21.39	19.93	40	3291	121045	34832555
Anxiety	20.31	19.93	35	3296	99393	34854207

FDA Adverse Event Reporting System (Geriatric)

MedDRA adverse event term	Likelihood ratio	Likelihood ratio threshold	Patients taking drug having adverse event	Patients taking drug not having adverse event	Patients not taking drug having adverse event	Patients not taking drug not having adverse event
Completed suicide	366.58	15.06	292	11013	245475	79487608
Accidental death	296.61	15.06	77	11228	4214	79728869
Toxicity to various agents	261.23	15.06	309	10996	421231	79311852
Drug hypersensitivity	222.05	15.06	241	11064	298675	79434408
Serotonin syndrome	76.49	15.06	58	11247	44969	79688114
Overdose	73.17	15.06	109	11196	184097	79548986
Anxiety	54.20	15.06	113	11192	248399	79484684
Coronary artery disease	46.97	15.06	52	11253	65422	79667661
Depression	45.42	15.06	97	11208	216693	79516390
Clonus	41.52	15.06	20	11285	6820	79726263
Deep vein thrombosis	40.22	15.06	66	11239	120853	79612230
Injury	35.31	15.06	49	11256	77447	79655636
Purpura senile	34.15	15.06	9	11296	521	79732562
Tarsal tunnel syndrome	34.05	15.06	9	11296	527	79732556
Myocardial infarction	32.51	15.06	77	11228	184052	79549031
Off label use	31.65	15.06	50	11255	907165	78825918
Drug withdrawal syndrome	31.00	15.06	31	11274	34687	79698396
Hyperlipidaemia	30.39	15.06	27	11278	26066	79707017
Emotional distress	29.10	15.06	32	11273	39937	79693146
Muscle rigidity	28.12	15.06	23	11282	19859	79713224
Neutropenia	27.56	15.06	4	11301	287706	79445377
Hyperreflexia	26.79	15.06	16	11289	8369	79724714
Intervertebral disc protrusion	26.64	15.06	24	11281	23597	79709486
Resorption bone increased	25.07	15.06	9	11296	1466	79731617
Respiratory arrest	24.16	15.06	35	11270	57515	79675568
Vertigo positional	24.11	15.06	11	11294	3319	79729764
Vestibular disorder	23.93	15.06	10	11295	2445	79730638
Back injury	23.46	15.06	16	11289	10507	79722576
Cardio-respiratory arrest	22.05	15.06	48	11257	108462	79624621
Mydriasis	22.04	15.06	19	11286	17624	79715459
Poisoning	21.53	15.06	22	11283	25250	79707833
Gastrooesophageal reflux disease	21.05	15.06	46	11259	104200	79628883
Muscle spasms	20.64	15.06	63	11242	174667	79558416
Migraine	20.46	15.06	41	11264	87452	79645631
Infusion related reaction	20.28	15.06	4	11301	230233	79502850
Spinal stenosis	19.71	15.06	17	11288	15774	79717309
Bronchitis	19.23	15.06	51	11254	130593	79602490
Body height decreased	19.02	15.06	13	11292	8567	79724516
Thrombocytopenia	18.88	15.06	7	11298	265252	79467831
Neck pain	18.43	15.06	36	11269	75381	79657702
Chest pain	18.39	15.06	84	11221	282220	79450863
Febrile neutropenia	18.39	15.06	5	11300	230994	79502089
Suicidal behaviour	18.22	15.06	9	11296	3238	79729845
Drug abuser	17.99	15.06	11	11294	6002	79727081
Cerebrovascular accident	17.42	15.06	55	11250	155237	79577846
Drug dependence	17.41	15.06	25	11280	40744	79692339
Back pain	16.57	15.06	86	11219	304094	79428989
Road traffic accident	16.10	15.06	25	11280	43639	79689444
Angina unstable	15.20	15.06	15	11290	16512	79716571

FDA Adverse Event Reporting System (Pediatric)

None

Pharmacologic Action:

Source	Code	Description
MeSH PA	D009465	Neuromuscular Agents
MeSH PA	D018373	Peripheral Nervous System Agents
FDA PE	N0000175730	Centrally-mediated Muscle Relaxation
FDA EPC	N0000175737	Muscle Relaxant

Drug Use | Suggest Off label Use Form| |View source of the data|

Disease	Relation	SNOMED_ID	DOID
Spasticity	indication	221360009
Acute nephropathy	contraindication	58574008
Hepatic failure	contraindication	59927004
Hemolytic anemia	contraindication	61261009	DOID:583
Acute hepatic failure	contraindication	197270009
Chronic Hepatic Disease	contraindication

🐶 Veterinary Drug Use

None

🐶 Veterinary products

None

Acid dissociation constants calculated using MoKa v3.0.0

Dissociation level	Dissociation constant	Type (acidic/basic)
pKa1	13.45	acidic

Orange Book patent data (new drug applications)

Formulation strength	Trade name	Applicant	Application number	Approval date	Type	Dose form	Route	Patent number	Patent expiration date	Patent use
800MG	SKELAXIN	KING PHARMS	N013217	Aug. 30, 2002	DISCN	TABLET	ORAL	7122566	Feb. 6, 2026	TREATMENT OF MUSCULOSKELETAL CONDITIONS

Orange Book exclusivity data (new drug applications)

None

Bioactivity Summary:

None

External reference:

ID	Source
4018807	VUID
N0000147110	NUI
D00773	KEGG_DRUG
4018807	VANDF
C0163055	UMLSCUI
CHEBI:6797	CHEBI
CHEMBL1079604	ChEMBL_ID
DB00660	DRUGBANK_ID
15459	PUBCHEM_CID
C011301	MESH_SUPPLEMENTAL_RECORD_UI
7609	IUPHAR_LIGAND_ID
1027	INN_ID
1NMA9J598Y	UNII
204315	RXNORM
1680	MMSL
172287	MMSL
5062	MMSL
d00964	MMSL
001673	NDDF
404863006	SNOMEDCT_US
87599003	SNOMEDCT_US

Pharmaceutical products:

Product	Category	Ingredients	NDC	Form	Quantity	Route	Marketing	Label
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0115-1745	TABLET	400 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0115-1745	TABLET	400 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0115-1745	TABLET	400 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0115-1748	TABLET	800 mg	ORAL	NDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0185-0448	TABLET	800 mg	ORAL	ANDA	17 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0185-0448	TABLET	800 mg	ORAL	ANDA	17 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0276-0508	TABLET	400 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0527-1435	TABLET	800 mg	ORAL	ANDA	19 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0527-1435	TABLET	800 mg	ORAL	ANDA	19 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0591-2341	TABLET	800 mg	ORAL	ANDA	19 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0904-6831	TABLET	800 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	0904-6831	TABLET	800 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	10544-002	TABLET	800 mg	ORAL	NDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	10544-144	TABLET	800 mg	ORAL	ANDA	20 sections
SKELAXIN	HUMAN PRESCRIPTION DRUG LABEL	1	10544-524	TABLET	800 mg	ORAL	NDA	20 sections
SKELAXIN	HUMAN PRESCRIPTION DRUG LABEL	1	16590-207	TABLET	800 mg	ORAL	NDA	20 sections
METAXALONE	HUMAN PRESCRIPTION DRUG LABEL	1	16590-346	TABLET	800 mg	ORAL	NDA	20 sections
Skelaxin	HUMAN PRESCRIPTION DRUG LABEL	1	21695-123	TABLET	800 mg	ORAL	NDA	21 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	21695-585	TABLET	800 mg	ORAL	ANDA	19 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	33261-724	TABLET	800 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	42254-040	TABLET	800 mg	ORAL	NDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	42291-587	TABLET	800 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	42494-449	TABLET	400 mg	ORAL	ANDA	21 sections
METAXALONE	HUMAN PRESCRIPTION DRUG LABEL	1	42549-650	TABLET	800 mg	ORAL	NDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	45865-942	TABLET	800 mg	ORAL	ANDA	19 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	45865-985	TABLET	800 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	50090-3174	TABLET	800 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	50090-3650	TABLET	800 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	50090-3650	TABLET	800 mg	ORAL	ANDA	20 sections
Metaxalone	HUMAN PRESCRIPTION DRUG LABEL	1	50090-3670	TABLET	800 mg	ORAL	ANDA	19 sections