Drug interactions
Levonorgestrel + Pentobarbital
Severity: Moderate
Levonorgestrel and Pentobarbital: moderate interaction.
Last updated
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 reduce levonorgestrel concentrations, risking contraceptive failure. The concern is greatest with oral and emergency dosing and with prolonged barbiturate use.
What this interaction means in plain words
Levonorgestrel and Pentobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Barbiturate-mediated induction of CYP3A4 increases levonorgestrel metabolism.
What to do
Use a non-hormonal or additional barrier method while on pentobarbital and for several weeks after stopping. For emergency contraception, consider a copper IUD.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Levonorgestrel
Frequently asked questions
Can I take Levonorgestrel with Pentobarbital?
MediHelp rates the interaction as moderate. Levonorgestrel and Pentobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Barbiturates induce hepatic enzymes and can reduce levonorgestrel concentrations, risking contraceptive failure. The concern is greatest with oral and emergency dosing and with prolonged barbiturate use.
How serious is the interaction between Levonorgestrel and Pentobarbital?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-hormonal or additional barrier method while on pentobarbital and for several weeks after stopping. For emergency contraception, consider a copper IUD.
What other medicines interact with Levonorgestrel?
MediHelp also lists interactions of Levonorgestrel with, for example, Amobarbital, Apalutamide, Belzutifan. The full list is on the Levonorgestrel page.
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