Drug interactions
Amobarbital + Phenobarbital
Severity: Major
Amobarbital and Phenobarbital: 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
Two barbiturates together produce additive CNS and respiratory depression. Phenobarbital also induces enzymes, adding to the effect on other drugs.
What this interaction means in plain words
Amobarbital and Phenobarbital 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 GABA-A mediated CNS depression.
What to do
Avoid unintended duplicate barbiturate therapy. If both are needed, monitor sedation and respiratory status and reduce doses.
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 Amobarbital
- Amobarbital + Calcium / magnesium / potassium / sodium oxybates Contraindicated
- Amobarbital + Doravirine Contraindicated
- Amobarbital + Elbasvir / grazoprevir Contraindicated
- Amobarbital + Isavuconazonium Contraindicated
- Amobarbital + Isocarboxazid Contraindicated
- Amobarbital + Lonafarnib Contraindicated
Frequently asked questions
Can I take Amobarbital with Phenobarbital?
MediHelp rates the interaction as major. Amobarbital and Phenobarbital 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. Two barbiturates together produce additive CNS and respiratory depression. Phenobarbital also induces enzymes, adding to the effect on other drugs.
How serious is the interaction between Amobarbital and Phenobarbital?
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 unintended duplicate barbiturate therapy. If both are needed, monitor sedation and respiratory status and reduce doses.
What other medicines interact with Amobarbital?
MediHelp also lists interactions of Amobarbital with, for example, Calcium / magnesium / potassium / sodium oxybates, Doravirine, Elbasvir / grazoprevir. The full list is on the Amobarbital page.
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