Category: signaling
Skeletal muscle relaxants split by mechanism. Centrally-acting (act on spinal cord + brainstem to reduce reflex spasm + spasticity): cyclobenzaprine (TCA-related, 5-HT2 antagonism + central anticholinergic), methocarbamol (mechanism unclear, possibly central depressant via NMDA or carbamate effects), carisoprodol (prodrug → meprobamate, GABA-A allosteric — abuse potential), orphenadrine (NMDA + H1 + muscarinic antagonist — also covered in CNS-4), tizanidine (α2-adrenergic agonist, similar to clonidine — covered conceptually in adrenergic but distinct indication), baclofen (GABA-B agonist — covered in gaba_a_receptor_signaling). Direct-acting on muscle: dantrolene blocks RYR1 → reduces Ca²⁺ release from SR → malignant hyperthermia antidote + chronic spasticity (MS, SCI).