Drug interactions
Etonogestrel + Pentobarbital
Severity: Major
Etonogestrel 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
Barbiturates induce hepatic enzymes and can lower etonogestrel concentrations enough to cause contraceptive failure. Unintended pregnancy is the main concern.
What this interaction means in plain words
Etonogestrel 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
Pentobarbital induces CYP3A4, increasing etonogestrel metabolism and reducing its exposure.
What to do
Use a non-hormonal method such as a copper IUD or add a reliable barrier method during treatment and for several weeks after stopping.
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 Etonogestrel
Frequently asked questions
Can I take Etonogestrel with Pentobarbital?
MediHelp rates the interaction as major. Etonogestrel 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. Barbiturates induce hepatic enzymes and can lower etonogestrel concentrations enough to cause contraceptive failure. Unintended pregnancy is the main concern.
How serious is the interaction between Etonogestrel 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: Use a non-hormonal method such as a copper IUD or add a reliable barrier method during treatment and for several weeks after stopping.
What other medicines interact with Etonogestrel?
MediHelp also lists interactions of Etonogestrel with, for example, Amobarbital, Armodafinil, Bosentan. The full list is on the Etonogestrel page.
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