Drug interactions
Clonazepam + Codeine
Severity: Major
Clonazepam and Codeine: major interaction.
Last updated Sources: US FDA label
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
Combining an opioid with a benzodiazepine produces additive central nervous system and respiratory depression. This can cause profound sedation, respiratory failure, coma and death, and regulators have issued boxed warnings for the combination.
What this interaction means in plain words
Clonazepam and Codeine 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.
Clonazepam belongs to Central Nervous System; Codeine belongs to Musculoskeletal.
Why it happens
Additive CNS and respiratory depression through opioid receptor agonism and GABA-A potentiation.
What to do
Avoid the combination where possible; if it is necessary, use the lowest effective doses for the shortest duration and monitor for sedation and respiratory depression. Counsel patients and caregivers to avoid alcohol and driving.
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?
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References
Other interactions of Codeine
- Alvimopan + Codeine Contraindicated
- Codeine + Isocarboxazid Contraindicated
- Codeine + Olanzapine / samidorphan Contraindicated
- Codeine + Phenelzine Contraindicated
- Codeine + Tranylcypromine Contraindicated
- Alfentanil + Codeine Major
Other interactions of Clonazepam
- Calcium / magnesium / potassium / sodium oxybates + Clonazepam Contraindicated
- Clonazepam + Sodium oxybate Contraindicated
- Alfentanil + Clonazepam Major
- Alprazolam + Clonazepam Major
- Amobarbital + Clonazepam Major
- Belladonna and opium + Clonazepam Major
Frequently asked questions
Can I take Clonazepam with Codeine?
MediHelp rates the interaction as major. Clonazepam and Codeine 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. Combining an opioid with a benzodiazepine produces additive central nervous system and respiratory depression. This can cause profound sedation, respiratory failure, coma and death, and regulators have issued boxed warnings for the combination.
How serious is the interaction between Clonazepam and Codeine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible; if it is necessary, use the lowest effective doses for the shortest duration and monitor for sedation and respiratory depression. Counsel patients and caregivers to avoid alcohol and driving.
What other medicines interact with Codeine?
MediHelp also lists interactions of Codeine with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Codeine page.
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