Orphenadrine

Category: pharmacological

Aliases: Norflex

Pharmacological Mechanism

Anticholinergic + NMDA antagonist + weak NET inhibitor — centrally-acting muscle relaxant for acute musculoskeletal pain. Anticholinergic burden similar to cyclobenzaprine; Beers-list problematic.

Half-Life (t½)

PO: 16.5h, IV: 16.5h

Dosing Guidelines

• PO: Typical 100 mg (Range: 100–200 mg)

Target Organ Systems

• nervous
• musculoskeletal

Pathways It Modulates

• Acetylcholine synthesis + degradation (inhibitor) — muscarinic M1 + NMDA antagonist
• Muscarinic ACh receptor subtypes (inhibitor) — M1 + NMDA antagonist (skeletal muscle relaxant)

Chemical Identifiers

• PubChem CID: 4601
• Formula: C18H23NO
• Molecular weight: 269.39 g/mol
• InChIKey: QVYRGXJJSLMXQH-UHFFFAOYSA-N
• SMILES: CC1=CC=CC=C1C(C2=CC=CC=C2)OCCN(C)C

References

• PMID 7056281