Drug interactions
Amobarbital + Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate
Severity: Major
Amobarbital and Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate: major 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
Enzyme-inducing barbiturates speed the metabolism of contraceptive steroids and may lead to contraceptive failure and breakthrough bleeding. The effect can persist after the inducer is stopped.
What this interaction means in plain words
Amobarbital and Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate 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
Induction of CYP3A4 increases clearance of ethinylestradiol and levonorgestrel.
What to do
Use a non-hormonal or additional barrier method during therapy and for 28 days after stopping amobarbital, or select an alternative contraceptive.
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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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 Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate?
MediHelp rates the interaction as major. Amobarbital and Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate 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. Enzyme-inducing barbiturates speed the metabolism of contraceptive steroids and may lead to contraceptive failure and breakthrough bleeding. The effect can persist after the inducer is stopped.
How serious is the interaction between Amobarbital and Levonorgestrel oral / ethinylestradiol / ferrous bisglycinate?
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 or additional barrier method during therapy and for 28 days after stopping amobarbital, or select an alternative contraceptive.
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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