Drug interactions
Elvitegravir / cobicistat / emtricitabine / tenofovir df + Ethinyl estradiol-drospirenone
Severity: Major
Elvitegravir / cobicistat / emtricitabine / tenofovir df 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
Cobicistat inhibits CYP3A4, and drospirenone is partly CYP3A4 metabolized, so its exposure and the potassium-raising effect may increase. Ethinyl estradiol levels may also change, affecting contraceptive reliability.
What this interaction means in plain words
Elvitegravir / cobicistat / emtricitabine / tenofovir df 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.
Why it happens
Cobicistat inhibits CYP3A4, reducing drospirenone clearance, with variable effects on ethinyl estradiol.
What to do
Consider an alternative contraceptive, as labeling advises against drospirenone with this regimen because of the hyperkalemia risk. If used, monitor serum potassium and use a backup method.
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
Frequently asked questions
Can I take Elvitegravir / cobicistat / emtricitabine / tenofovir df with Ethinyl estradiol-drospirenone?
MediHelp rates the interaction as major. Elvitegravir / cobicistat / emtricitabine / tenofovir df 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. Cobicistat inhibits CYP3A4, and drospirenone is partly CYP3A4 metabolized, so its exposure and the potassium-raising effect may increase. Ethinyl estradiol levels may also change, affecting contraceptive reliability.
How serious is the interaction between Elvitegravir / cobicistat / emtricitabine / tenofovir df 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: Consider an alternative contraceptive, as labeling advises against drospirenone with this regimen because of the hyperkalemia risk. If used, monitor serum potassium and use a backup method.
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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