Drug interactions
Drospirenone + Fosamprenavir
Severity: Major
Drospirenone and Fosamprenavir: 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
Fosamprenavir (as amprenavir) alters hormonal contraceptive exposure and can reduce amprenavir levels; combining may compromise contraceptive efficacy and antiretroviral exposure. Hormonal contraceptive concentrations are changed unpredictably, and drospirenone may raise potassium.
What this interaction means in plain words
Drospirenone and Fosamprenavir 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
Fosamprenavir/ritonavir modulates CYP3A4 and other enzymes, altering metabolism of the contraceptive hormones.
What to do
Avoid hormonal contraceptives with fosamprenavir where possible and use non-hormonal or alternative methods. If used, monitor potassium and contraceptive efficacy.
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 Drospirenone
Frequently asked questions
Can I take Drospirenone with Fosamprenavir?
MediHelp rates the interaction as major. Drospirenone and Fosamprenavir 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. Fosamprenavir (as amprenavir) alters hormonal contraceptive exposure and can reduce amprenavir levels; combining may compromise contraceptive efficacy and antiretroviral exposure. Hormonal contraceptive concentrations are changed unpredictably, and drospirenone may raise potassium.
How serious is the interaction between Drospirenone and Fosamprenavir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid hormonal contraceptives with fosamprenavir where possible and use non-hormonal or alternative methods. If used, monitor potassium and contraceptive efficacy.
What other medicines interact with Drospirenone?
MediHelp also lists interactions of Drospirenone with, for example, Belzutifan, Bosentan, Carbamazepine. The full list is on the Drospirenone page.
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