Drug interactions
Chlorzoxazone + Midazolam
Severity: Major
Chlorzoxazone and Midazolam: major interaction.
Last updated Sources: UK SmPC
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Midazolam is a potent sedative, and chlorzoxazone adds further CNS depression, increasing the chance of deep sedation, impaired airway reflexes and respiratory depression. The risk is greatest with parenteral dosing or in frail patients.
What this interaction means in plain words
Chlorzoxazone and Midazolam can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Chlorzoxazone belongs to Musculoskeletal; Midazolam belongs to Central Nervous System.
Why it happens
Additive CNS and respiratory depression via GABA-A potentiation and muscle relaxant sedation.
What to do
Reduce midazolam doses and titrate slowly, with continuous monitoring of respiratory rate and oxygen saturation when used for procedural sedation. Avoid outpatient co-use when possible, or counsel on avoiding driving and alcohol.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Chlorzoxazone and Midazolam, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
Other interactions of Chlorzoxazone
Other interactions of Midazolam
- Atazanavir + Midazolam Contraindicated
- Cobicistat + Midazolam Contraindicated
- Darunavir + Midazolam Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Midazolam Contraindicated
- Fosamprenavir + Midazolam Contraindicated
- Indinavir + Midazolam Contraindicated
Frequently asked questions
Can I take Chlorzoxazone with Midazolam?
MediHelp rates the interaction as major. Chlorzoxazone and Midazolam can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Midazolam is a potent sedative, and chlorzoxazone adds further CNS depression, increasing the chance of deep sedation, impaired airway reflexes and respiratory depression. The risk is greatest with parenteral dosing or in frail patients.
How serious is the interaction between Chlorzoxazone and Midazolam?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce midazolam doses and titrate slowly, with continuous monitoring of respiratory rate and oxygen saturation when used for procedural sedation. Avoid outpatient co-use when possible, or counsel on avoiding driving and alcohol.
What other medicines interact with Chlorzoxazone?
MediHelp also lists interactions of Chlorzoxazone with, for example, Alfentanil, Alprazolam, Amobarbital. The full list is on the Chlorzoxazone page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
