Comparative Pharmacology
Head-to-head clinical analysis: CHLORZOXAZONE versus RELA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: CHLORZOXAZONE versus RELA.
CHLORZOXAZONE vs RELA
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.
RELA (Carisoprodol) is a centrally acting muscle relaxant that modulates GABA-A receptor activity and blocks interneuronal activity in the descending reticular formation and spinal cord, resulting in muscle relaxation without directly affecting the neuromuscular junction. Its metabolite, meprobamate, contributes to anxiolytic and sedative effects.
250-500 mg orally 3-4 times daily, maximum 750 mg 4 times daily.
Adults: 250-350 mg orally 3-4 times daily.
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 approximately 20–30 hours; prolonged in elderly and renal impairment
Primarily hepatic metabolism followed by renal excretion of metabolites; <1% excreted unchanged in urine; minor biliary/fecal elimination.
Primarily renal excretion of unchanged drug and metabolites; 70% to 80% eliminated via urine, remainder biliary/fecal
Category C
Category C
Skeletal Muscle Relaxant
Skeletal Muscle Relaxant
"The metabolism of Sulfisoxazole can be decreased when combined with Chlorzoxazone."