Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
REVONTO vs CHLORZOXAZONE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Remimazolam is a benzodiazepine that acts as a positive allosteric modulator of GABA-A receptors, enhancing the effects of GABA to produce sedation and anxiolysis.
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.
Induction and maintenance of procedural sedation,General anesthesia induction and maintenance
Adjunct for relief of acute painful musculoskeletal conditions associated with muscle spasm
4 mg orally twice daily, with or without food.
250-500 mg orally 3-4 times daily, maximum 750 mg 4 times daily.
Terminal elimination half-life is approximately 18–20 hours in healthy adults, allowing once-daily dosing.
Terminal elimination half-life approximately 1–2 hours; clinically relevant for muscle relaxant effect duration.
Rapidly hydrolyzed by nonspecific carboxylesterases in the blood and liver to an inactive metabolite (CNS7054); not significantly metabolized by CYP450 enzymes.
Hepatic, primarily via CYP2E1, also CYP1A2 and CYP3A4
Renal excretion of unchanged drug accounts for <1% of the dose; fecal excretion via biliary elimination is the primary route (≈90%), with the remainder as metabolites.
Primarily hepatic metabolism followed by renal excretion of metabolites; <1% excreted unchanged in urine; minor biliary/fecal elimination.
Highly protein-bound (>99%), primarily to albumin and α1-acid glycoprotein.
Approximately 90–95% bound, primarily to albumin.
Volume of distribution is approximately 1.5–2.0 L/kg, indicating extensive extravascular distribution.
0.46–0.64 L/kg; indicates distribution into total body water.
Oral bioavailability is approximately 30–40% due to first-pass metabolism.
Oral: nearly complete; rapidly absorbed with extensive first-pass metabolism; systemic bioavailability approximately 30–50% due to first-pass effect.
No dose adjustment required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). Not recommended for severe renal impairment (Cr Cl <30 m L/min) or end-stage renal disease.
No specific guidelines; use with caution in severe renal impairment (GFR <30 m L/min) due to potential accumulation of active metabolite.
Mild hepatic impairment (Child-Pugh A): no dose adjustment. Moderate (Child-Pugh B): reduce dose to 2 mg twice daily. Severe (Child-Pugh C): not recommended.
Contraindicated in hepatic impairment; avoid use in Child-Pugh class B or C due to risk of hepatotoxicity.
Safety and efficacy not established. Use is not recommended in pediatric patients.
Not established; safety and efficacy not studied in pediatric patients.
No specific dose adjustment recommended; monitor renal function and consider age-related decline in renal function.
Initiate at lower end of dosing range (250 mg 3-4 times daily); monitor for CNS effects (dizziness, drowsiness) and liver function.
None
None
Respiratory depression and apnea,Hypotension and bradycardia,Risk of sedation and respiratory depression in elderly or debilitated patients,Potential for physical dependence and abuse,Need for continuous monitoring of vital signs
May cause drowsiness, dizziness, or impaired coordination. Caution in patients with hepatic impairment. Discontinue if hypersensitivity reactions occur. Avoid concurrent use with alcohol or other CNS depressants.
Hypersensitivity to remimazolam or benzodiazepines,Acute narrow-angle glaucoma,Severe hepatic impairment (Child-Pugh class C)
Hypersensitivity to chlorzoxazone or any component of the formulation; impaired hepatic function
Avoid high-fat meals as they can significantly increase drug absorption and risk of adverse effects. Grapefruit and grapefruit juice should be avoided due to potential CYP3A4 inhibition affecting metabolism. Limit caffeine intake as combination may exacerbate side effects like anxiety and palpitations.
No significant food interactions. Take with or without food. Grapefruit juice may increase drug levels; avoid large quantities.
First trimester: Neural tube defects, cardiovascular malformations, and oral clefts reported in animal studies; human data limited. Second trimester: Increased risk of fetal growth restriction and preterm birth. Third trimester: Potential for neonatal respiratory depression, hypotonia, and withdrawal syndrome if used near term.
Teratogenic risk in humans is not well-studied. No major teratogenic effects have been reported in animal studies. However, as with all medications, use during pregnancy only if clearly needed and after weighing risks vs. benefits. Avoid during first trimester unless necessary.
Excreted in breast milk; M/P ratio approximately 0.85. Not recommended due to risk of infant sedation, poor feeding, and potential long-term neurodevelopmental effects. Consider alternative therapies.
Not recommended during breastfeeding due to potential for sedation in the infant. No M/P ratio data available.
Increased clearance during pregnancy may necessitate dose adjustment; therapeutic drug monitoring recommended to maintain target trough concentrations. Postpartum, dose reduction may be required due to altered pharmacokinetics.
No dosage adjustment specific to pregnancy is required based on pharmacokinetic data; however, clinical response should be monitored.
REVONTO is a proprietary formulation not recognized in standard medical literature. Verify with pharmacist for active ingredient(s) and dosing. If it contains naltrexone-bupropion combination (brand name Contrave), use with caution in patients with seizure history or eating disorders. Monitor blood pressure regularly due to possible hypertensive effects. Contraindicated with concomitant MAOIs or during abrupt opioid withdrawal.
Chlorzoxazone is a centrally acting muscle relaxant used for acute musculoskeletal pain. Onset of action is within 1 hour; peak effect at 1-2 hours. Monitor for hepatotoxicity, especially with prolonged use or high doses. Can cause drowsiness and impair motor skills; avoid concurrent use with alcohol or other CNS depressants. Tablets may be crushed for patients with swallowing difficulties.
Take with a low-fat meal to reduce gastrointestinal side effects and improve tolerability.,Avoid alcoholic beverages as they may increase the risk of seizures and hepatotoxicity.,Report any signs of allergic reaction (rash, itching, swelling) or mood changes immediately.,Do not discontinue abruptly; taper under medical supervision to avoid withdrawal symptoms.,Store at room temperature away from moisture and heat.
Take exactly as prescribed; do not increase dose or frequency.,May cause drowsiness or dizziness; avoid driving or operating machinery until you know how it affects you.,Avoid alcohol and other CNS depressants while taking this medication.,Report signs of liver problems: dark urine, yellowing of eyes/skin, persistent nausea, abdominal pain.,Do not suddenly stop taking if used long-term; taper under medical supervision to avoid withdrawal.
No interactions on record
"Lumacaftor is a strong inducer of cytochrome P450 (CYP) 3A4 and other drug-metabolizing enzymes, including CYP2E1. Chlorzoxazone is primarily metabolized by CYP2E1 to its inactive metabolite. Concomitant use increases CYP2E1 activity, leading to accelerated chlorzoxazone clearance and reduced systemic exposure, potentially diminishing its therapeutic effect as a muscle relaxant."
"Chlorzoxazone, a centrally acting muscle relaxant, inhibits the metabolism of diltiazem, a calcium channel blocker, via competitive inhibition of CYP3A4. This leads to increased plasma concentrations of diltiazem, potentially causing enhanced negative chronotropic and vasodilatory effects, resulting in bradycardia, hypotension, or atrioventricular block. Patients may experience dizziness, syncope, or exacerbate heart failure symptoms."
"Butalbital, a barbiturate, induces hepatic cytochrome P450 enzymes (particularly CYP2E1), accelerating the metabolism of chlorzoxazone, a centrally acting muscle relaxant primarily metabolized by CYP2E1. This results in reduced plasma concentrations of chlorzoxazone, leading to diminished therapeutic efficacy and potential loss of symptom control. Clinically, patients may experience inadequate muscle relaxation, requiring dose adjustments or alternative therapy."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about REVONTO vs CHLORZOXAZONE, answered by our medical review team.
REVONTO is a Skeletal Muscle Relaxant that works by Remimazolam is a benzodiazepine that acts as a positive allosteric modulator of GABA-A receptors, enhancing the effects of GABA to produce sedation and anxiolysis.. CHLORZOXAZONE is a Skeletal Muscle Relaxant that works by 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.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between REVONTO and CHLORZOXAZONE depend on the specific clinical indication. These are both Skeletal Muscle Relaxant agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of REVONTO is: 4 mg orally twice daily, with or without food.. The standard adult dose of CHLORZOXAZONE is: 250-500 mg orally 3-4 times daily, maximum 750 mg 4 times daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between REVONTO and CHLORZOXAZONE in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. REVONTO is classified as Category C. First trimester: Neural tube defects, cardiovascular malformations, and oral clefts reported in animal studies; human data limited. Second trimester: Increased risk of fetal growth. CHLORZOXAZONE is classified as Category C. Teratogenic risk in humans is not well-studied. No major teratogenic effects have been reported in animal studies. However, as with all medications, use during pregnancy only if cl. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.