Drug interactions
Fludrocortisone + Rifampin
Severity: Major
Fludrocortisone and Rifampin: major interaction.
Last updated Sources: US FDA label
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
Rifampin induces CYP3A4 and can lower fludrocortisone exposure. In patients with adrenal insufficiency this can cause loss of mineralocorticoid effect, with hypotension, hyponatremia and hyperkalemia, and adrenal crisis has been reported with rifampin and corticosteroid replacement.
What this interaction means in plain words
Fludrocortisone and Rifampin 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
Rifampin induces CYP3A4 and other hepatic enzymes, accelerating fludrocortisone metabolism.
What to do
Monitor blood pressure, sodium, potassium and plasma renin, and increase the fludrocortisone dose as needed while on rifampin. Re-check the dose after rifampin is stopped.
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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References
Other interactions of Fludrocortisone
Frequently asked questions
Can I take Fludrocortisone with Rifampin?
MediHelp rates the interaction as major. Fludrocortisone and Rifampin 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. Rifampin induces CYP3A4 and can lower fludrocortisone exposure. In patients with adrenal insufficiency this can cause loss of mineralocorticoid effect, with hypotension, hyponatremia and hyperkalemia, and adrenal crisis has been reported with rifampin and corticosteroid replacement.
How serious is the interaction between Fludrocortisone and Rifampin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure, sodium, potassium and plasma renin, and increase the fludrocortisone dose as needed while on rifampin. Re-check the dose after rifampin is stopped.
What other medicines interact with Fludrocortisone?
MediHelp also lists interactions of Fludrocortisone with, for example, Mifepristone, Aldesleukin, Amphotericin b. The full list is on the Fludrocortisone page.
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