Drug interactions
Efavirenz + Ethinyl estradiol-drospirenone
Severity: Major
Efavirenz and Ethinyl estradiol-drospirenone: 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
Efavirenz can alter contraceptive hormone levels and is associated with reduced efficacy of hormonal contraceptives, including implants. Efavirenz is also teratogenic in some circumstances.
What this interaction means in plain words
Efavirenz and Ethinyl estradiol-drospirenone 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.
Efavirenz belongs to Anti Virals; Ethinyl estradiol-drospirenone belongs to Endocrine.
Why it happens
Efavirenz induces CYP3A4 and alters metabolism of contraceptive hormones.
What to do
Use a reliable non-hormonal method or an IUD in addition to or instead of combined hormonal pills. Consult HIV guidelines for contraception choice.
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 Ethinyl estradiol-drospirenone
- Ethinyl estradiol-drospirenone + Fezolinetant Contraindicated
- Ethinyl estradiol-drospirenone + Ombitasvir / paritaprevir / ritonavir Contraindicated
- Ethinyl estradiol-drospirenone + Ombitasvir / paritaprevir / ritonavir and dasabuvir Contraindicated
- Ethinyl estradiol-drospirenone + Tranexamic acid Contraindicated
- Aminocaproic acid + Ethinyl estradiol-drospirenone Major
- Amobarbital + Ethinyl estradiol-drospirenone Major
Other interactions of Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Efavirenz with Ethinyl estradiol-drospirenone?
MediHelp rates the interaction as major. Efavirenz and Ethinyl estradiol-drospirenone 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. Efavirenz can alter contraceptive hormone levels and is associated with reduced efficacy of hormonal contraceptives, including implants. Efavirenz is also teratogenic in some circumstances.
How serious is the interaction between Efavirenz and Ethinyl estradiol-drospirenone?
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 reliable non-hormonal method or an IUD in addition to or instead of combined hormonal pills. Consult HIV guidelines for contraception choice.
What other medicines interact with Ethinyl estradiol-drospirenone?
MediHelp also lists interactions of Ethinyl estradiol-drospirenone with, for example, Fezolinetant, Ombitasvir / paritaprevir / ritonavir, Ombitasvir / paritaprevir / ritonavir and dasabuvir. The full list is on the Ethinyl estradiol-drospirenone page.
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