Drug interactions
Fludrocortisone + Isoniazid
Severity: Minor
Fludrocortisone and Isoniazid: minor 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
Isoniazid might slightly reduce fludrocortisone clearance via CYP3A4 inhibition, enhancing mineralocorticoid effects. Fluid retention, hypokalemia and hypertension could follow, though this is unlikely at usual doses.
What this interaction means in plain words
Fludrocortisone and Isoniazid have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Fludrocortisone belongs to Endocrine; Isoniazid belongs to Anti Bacterial.
Why it happens
Weak CYP3A4 inhibition by isoniazid may raise fludrocortisone exposure.
What to do
Monitor blood pressure, edema and serum potassium. Adjust the fludrocortisone dose if signs of excess effect appear.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Fludrocortisone and Isoniazid, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Isoniazid
Other interactions of Fludrocortisone
Frequently asked questions
Can I take Fludrocortisone with Isoniazid?
MediHelp rates the interaction as minor. Fludrocortisone and Isoniazid have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Isoniazid might slightly reduce fludrocortisone clearance via CYP3A4 inhibition, enhancing mineralocorticoid effects. Fluid retention, hypokalemia and hypertension could follow, though this is unlikely at usual doses.
How serious is the interaction between Fludrocortisone and Isoniazid?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure, edema and serum potassium. Adjust the fludrocortisone dose if signs of excess effect appear.
What other medicines interact with Isoniazid?
MediHelp also lists interactions of Isoniazid with, for example, Bacillus calmette-guerin substrain tice, Benzhydrocodone / acetaminophen, Carbamazepine. The full list is on the Isoniazid page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
