Drug interactions
Morphine + Pentobarbital
Severity: Major
Morphine and Pentobarbital: 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 barbiturate produces additive central nervous system and respiratory depression. Profound sedation, hypotension, respiratory failure, coma or death can result, particularly at higher doses or in frail patients.
What this interaction means in plain words
Morphine and Pentobarbital 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.
Why it happens
Additive CNS and respiratory depression through opioid receptor agonism and enhanced GABA-A receptor activity.
What to do
Avoid the combination where possible; if needed, use the lowest effective doses and monitor sedation level and respiratory rate closely. Ensure resuscitation equipment is available when given parenterally.
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 Morphine
- Alvimopan + Morphine Contraindicated
- Isocarboxazid + Morphine Contraindicated
- Morphine + Olanzapine / samidorphan Contraindicated
- Morphine + Phenelzine Contraindicated
- Morphine + Tranylcypromine Contraindicated
- Alfentanil + Morphine Major
Frequently asked questions
Can I take Morphine with Pentobarbital?
MediHelp rates the interaction as major. Morphine and Pentobarbital 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 barbiturate produces additive central nervous system and respiratory depression. Profound sedation, hypotension, respiratory failure, coma or death can result, particularly at higher doses or in frail patients.
How serious is the interaction between Morphine and Pentobarbital?
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 needed, use the lowest effective doses and monitor sedation level and respiratory rate closely. Ensure resuscitation equipment is available when given parenterally.
What other medicines interact with Morphine?
MediHelp also lists interactions of Morphine with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Morphine page.
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