Comparative Pharmacology
Head-to-head clinical analysis: CHLORZOXAZONE versus ORPHENADRINE CITRATE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CHLORZOXAZONE versus ORPHENADRINE CITRATE.
CHLORZOXAZONE vs ORPHENADRINE CITRATE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Chlorzoxazone acts centrally on the spinal cord and subcortical areas of the brain to inhibit multisynaptic reflex arcs involved in producing and maintaining muscle spasm. It may also have some sedative effects.
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.
250-500 mg orally 3-4 times daily, maximum 750 mg 4 times daily.
100 mg orally twice daily. Maximum: 250 mg/day.
None Documented
None Documented
Clinical Note
moderateChlorzoxazone + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Chlorzoxazone is combined with Fluticasone propionate."
Clinical Note
moderateChlorzoxazone + Haloperidol
"The metabolism of Haloperidol can be decreased when combined with Chlorzoxazone."
Clinical Note
moderateChlorzoxazone + Tenofovir disoproxil
"The metabolism of Tenofovir disoproxil can be decreased when combined with Chlorzoxazone."
Clinical Note
moderateChlorzoxazone + Sulfisoxazole
Terminal elimination half-life approximately 1–2 hours; clinically relevant for muscle relaxant effect duration.
Terminal elimination half-life is approximately 14 hours (range 11–20 hours) in adults; may be prolonged in elderly or hepatic impairment.
Primarily hepatic metabolism followed by renal excretion of metabolites; <1% excreted unchanged in urine; minor biliary/fecal elimination.
Primarily renal excretion of metabolites; less than 10% excreted unchanged. Also undergoes biliary excretion with fecal elimination of conjugates.
Category C
Category A/B
Skeletal Muscle Relaxant
Skeletal Muscle Relaxant
"The metabolism of Sulfisoxazole can be decreased when combined with Chlorzoxazone."