Orphenadrine

Summary

Orphenadrine (CHEMBL900) is an approved small-molecule NMDA receptor antagonist (ATC M03BC51); indicated across 1 condition.

At a glance

• Status: Approved (max clinical phase 4)
• Modality: Small molecule
• ATC class: M03BC51
• Indications: 1 condition
• Clinical trials: 8
• Chemistry: 269.4 Da · C18H23NO

Identifiers

Drug identity and classification

Field	Value
ChEMBL ID	CHEMBL900
Name	Orphenadrine
Type	Small molecule
Max phase	4
FDA approved	yes
PubChem CID	4601
ChEBI	CHEBI:7789
ATC	M03BC51
Molecular formula	C18H23NO
Molecular weight	269.4
InChIKey	QVYRGXJJSLMXQH-UHFFFAOYSA-N

SMILES: CC1=CC=CC=C1C(C2=CC=CC=C2)OCCN(C)C

IUPAC name: N,N-dimethyl-2-[(2-methylphenyl)-phenylmethoxy]ethanamine

ChEBI definition: A tertiary amino compound which is the phenyl-o-tolylmethyl ether of 2-(dimethylamino)ethanol.

Pharmacological roles (ChEBI): NMDA receptor antagonist, H1-receptor antagonist, antiparkinson drug, parasympatholytic, muscle relaxant, muscarinic antagonist, antidyskinesia agent.

Also known as: Invagesic, Mefenamine, Mialgin, Norgesic, Orfenadrina, Orphenadrin, Orphenadrine, Orphengesic, orphenadrine, SID90341796, SID124880989, SID174006927

Parent form; salt/anhydrous children: CHEMBL1200395, CHEMBL1201023

Patent coverage: 2,345 distinct patent families (8,087 SureChEMBL compound mentions), from 2 matched compound structure(s). One matched structure accounts for 7,778 (96%) of the total. Mentions count patents naming the compound (not distinct inventions), so promiscuous / reference molecules inflate the mention figure — families are the dedup metric.

Targets

Targets

Broader ChEMBL bioactivity targets: 28 (assay-derived). Sample: Solute carrier family 22 member 2, Multidrug and toxin extrusion protein 1, Muscarinic acetylcholine receptor M4, 5-hydroxytryptamine receptor 2B, Alpha-2A adrenergic receptor, Histamine H2 receptor, Alpha-2B adrenergic receptor, Muscarinic acetylcholine receptor M5, D(1A) dopamine receptor, Glutamate [NMDA] receptor.

Bioactivity

ChEMBL activities: 42 potent at pChembl ≥ 5 of 50 total. Top 30 by potency (10 = 0.1 nM, 6 = 1 µM):

Target	pChembl	Type	Value	Unit	Activity ID
CHRM4	7.77	Ki	17	nM	CHEMBL_ACT_7714673
CHRM5	7.7	Ki	20	nM	CHEMBL_ACT_7714675
CHRM5	7.55	IC50	28	nM	CHEMBL_ACT_7714674
CHRM1	7.44	Ki	36	nM	CHEMBL_ACT_7714667
CHRM3	7.43	Ki	37	nM	CHEMBL_ACT_7714671
CHRM4	6.9	IC50	125	nM	CHEMBL_ACT_7714672
HTR2A	6.9	Ki	125	nM	CHEMBL_ACT_7716738
CHRM2	6.87	Ki	134	nM	CHEMBL_ACT_7714669
HRH1	6.84	Ki	144	nM	CHEMBL_ACT_7714639
CHRM1	6.83	IC50	148	nM	CHEMBL_ACT_7714666
P31390	6.79	IC50	162.2	nM	CHEMBL_ACT_12085960
CHRM3	6.76	IC50	175	nM	CHEMBL_ACT_7714670
SLC6A4	6.61	Ki	243	nM	CHEMBL_ACT_7716750
HTR2C	6.55	Ki	280	nM	CHEMBL_ACT_7716742
CHRM2	6.44	AC50	363.6	nM	CHEMBL_ACT_25196171
CHRM2	6.42	IC50	376	nM	CHEMBL_ACT_7714668
CYP2D6	6.4	IC50	400	nM	CHEMBL_ACT_7714598
HTR2A	6.36	IC50	436	nM	CHEMBL_ACT_7716737
SLC6A4	6.34	IC50	458	nM	CHEMBL_ACT_7716749
HTR6	6.28	Ki	521	nM	CHEMBL_ACT_7716748
HTR2C	6.27	IC50	534	nM	CHEMBL_ACT_7716741
ADRA2A	6.09	Ki	809	nM	CHEMBL_ACT_7746717
KCNH2	6.07	IC50	851.1	nM	CHEMBL_ACT_5219030
ADRA2B	6.06	Ki	865	nM	CHEMBL_ACT_7746719
CHRM1	6.01	AC50	977.6	nM	CHEMBL_ACT_25210583
HTR6	5.95	IC50	1121	nM	CHEMBL_ACT_7716747
HRH1	5.91	IC50	1241	nM	CHEMBL_ACT_7714638
ADRA2B	5.72	IC50	1895	nM	CHEMBL_ACT_7746718
DRD3	5.67	AC50	2116	nM	CHEMBL_ACT_25194946
HTR2B	5.67	Ki	2158	nM	CHEMBL_ACT_7716740

Target pathways

No target-pathway data for this drug (no mapped target genes).

Indications & clinical

Indications

1 indication (0 at ChEMBL trial phase 4).

The 1 indication record carries no mapped disease name (EFO/MeSH-only); none shown.

Clinical trials

Total trials: 8.

Phase distribution

Phase	Trials
PHASE4	5
Not specified	2
PHASE3	1

Top trials by phase / activity

NCT	Phase	Status	Title
NCT07109882	PHASE4	RECRUITING	Effectiveness of Chlorzoxazone Versus Orphenadrine Citrate in Alleviating Bruxism Pain
NCT02449369	PHASE4	COMPLETED	Intra-Venous Acetaminophen and Muscle Relaxants After Total Knee
NCT02665286	PHASE4	COMPLETED	Orphenadrine and Methocarbamol for LBP
NCT02958566	PHASE4	UNKNOWN	Multimodal Narcotic Limited Perioperative Pain Control With Colorectal Surgery
NCT05413902	PHASE4	COMPLETED	Multi-Modal Anesthesia Protocol in Pain Management of Patients Undergoing Posterior Lumbar Spinal Fusion Surgery
NCT02423395	PHASE3	RECRUITING	Study of Orphenadrine’ in the Treatment of Muscle Cramps in Patients With Cirrhosis
NCT01263652	Not specified	WITHDRAWN	Patient Preferences, Analgesic Delivery Method and Pain Reduction in Spine Patients
NCT04509336	Not specified	TERMINATED	Orphenadrine Versus Baclofen in Treatment of Muscle Cramps in Cirrhotic Patients

Clinical evidence (CIViC)

No CIViC predictive evidence (expected for non-precision-medicine drugs).

Pharmacology

Pharmacogenomics

No CPIC/DPWG dosing guideline or drug-level clinical/variant annotations in PharmGKB for this molecule.

Related molecules

Related molecules

No competitor molecules sharing a primary target (ChEMBL phase ≥2 or PubChem drug-class).