Comparative Pharmacology
Head-to-head clinical analysis: CHLORZOXAZONE versus ROBAXIN 750.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CHLORZOXAZONE versus ROBAXIN 750.
CHLORZOXAZONE vs ROBAXIN-750
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.
Methocarbamol, the active ingredient in Robaxin-750, is a centrally acting muscle relaxant. Its precise mechanism is not fully understood, but it is believed to cause general central nervous system depression, possibly through inhibition of polysynaptic reflexes at the spinal cord level.
250-500 mg orally 3-4 times daily, maximum 750 mg 4 times daily.
750 mg orally four times daily (total daily dose 3000 mg).
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: 1-2 hours (methocarbamol); clinical context: short half-life necessitates frequent dosing (q6h) and may lead to fluctuating plasma levels.
Primarily hepatic metabolism followed by renal excretion of metabolites; <1% excreted unchanged in urine; minor biliary/fecal elimination.
Renal: 90-95% as metabolites (mainly conjugated), <1% unchanged; biliary/fecal: minor; <2% eliminated in feces.
Category C
Category C
Skeletal Muscle Relaxant
Skeletal Muscle Relaxant
"The metabolism of Sulfisoxazole can be decreased when combined with Chlorzoxazone."