Drug interactions
Amobarbital + Levonorgestrel
Severity: Major
Amobarbital and Levonorgestrel: 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
Barbiturates can lower levonorgestrel concentrations and may cause contraceptive failure, including with emergency contraception.
What this interaction means in plain words
Amobarbital and Levonorgestrel 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.
Amobarbital belongs to Central Nervous System; Levonorgestrel belongs to Endocrine.
Why it happens
Barbiturate induction of CYP3A4 accelerates levonorgestrel metabolism.
What to do
Use an additional non-hormonal method or a non-affected method such as a copper IUD; for emergency contraception, consider a copper IUD or a higher levonorgestrel dose per local guidance.
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
Other interactions of Levonorgestrel
Frequently asked questions
Can I take Amobarbital with Levonorgestrel?
MediHelp rates the interaction as major. Amobarbital and Levonorgestrel 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 can lower levonorgestrel concentrations and may cause contraceptive failure, including with emergency contraception.
How serious is the interaction between Amobarbital and Levonorgestrel?
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 an additional non-hormonal method or a non-affected method such as a copper IUD; for emergency contraception, consider a copper IUD or a higher levonorgestrel dose per local guidance.
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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