Comparative Pharmacology
Head-to-head clinical analysis: ORPHENADRINE CITRATE versus RYANODEX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ORPHENADRINE CITRATE versus RYANODEX.
ORPHENADRINE CITRATE vs RYANODEX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Orphenadrine citrate is a centrally acting muscle relaxant with anticholinergic properties. Its exact mechanism of action is not fully understood, but it is believed to exert its effects by blocking muscarinic acetylcholine receptors and possibly by acting as an NMDA receptor antagonist. It may also have local anesthetic and antihistaminic properties.
Ryanodine receptor agonist; stabilizes the ryanodine receptor (RyR1) channel in skeletal muscle, reducing calcium leakage and improving excitation-contraction coupling.
100 mg orally twice daily. Maximum: 250 mg/day.
Dantrolene sodium: 2.5 mg/kg IV bolus, repeated as needed up to a cumulative dose of 10 mg/kg, then 1 mg/kg IV every 6 hours for 24-48 hours following malignant hyperthermia crisis.
None Documented
None Documented
Terminal elimination half-life is approximately 14 hours (range 11–20 hours) in adults; may be prolonged in elderly or hepatic impairment.
Terminal elimination half-life is approximately 1.5-2 hours in healthy adults; prolonged in patients with hepatic impairment.
Primarily renal excretion of metabolites; less than 10% excreted unchanged. Also undergoes biliary excretion with fecal elimination of conjugates.
Primarily hepatic metabolism; <1% excreted unchanged in urine. Biliary/fecal excretion of metabolites accounts for the majority of elimination.
Category A/B
Category C
Skeletal Muscle Relaxant
Skeletal Muscle Relaxant