Drug interactions
Felodipine + Isoniazid
Severity: Minor
Felodipine 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
Felodipine undergoes extensive CYP3A4 first-pass metabolism, and isoniazid may inhibit this weakly. Felodipine levels could rise, leading to hypotension, flushing, headache and peripheral edema.
What this interaction means in plain words
Felodipine 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.
Felodipine belongs to Cardiovascular; Isoniazid belongs to Anti Bacterial.
Why it happens
Weak CYP3A4 inhibition by isoniazid decreases felodipine metabolism.
What to do
Monitor blood pressure and for edema or dizziness when isoniazid is started. Lower the felodipine dose if hypotension occurs.
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?
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Other interactions of Isoniazid
Other interactions of Felodipine
- Felodipine + Itraconazole Contraindicated
- Aldesleukin + Felodipine Major
- Amifostine + Felodipine Major
- Apalutamide + Felodipine Major
- Atazanavir + Felodipine Major
- Carbamazepine + Felodipine Major
Frequently asked questions
Can I take Felodipine with Isoniazid?
MediHelp rates the interaction as minor. Felodipine 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. Felodipine undergoes extensive CYP3A4 first-pass metabolism, and isoniazid may inhibit this weakly. Felodipine levels could rise, leading to hypotension, flushing, headache and peripheral edema.
How serious is the interaction between Felodipine 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 and for edema or dizziness when isoniazid is started. Lower the felodipine dose if hypotension occurs.
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.
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