Drug interactions
Hydrocortisone + Terfenadine
Severity: Moderate
Hydrocortisone and Terfenadine: moderate 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
Terfenadine is withdrawn or contraindicated with CYP3A4 inhibitors because of QT prolongation and torsades de pointes. Hydrocortisone is not a significant CYP3A4 inhibitor, and the main concern is corticosteroid-related hypokalemia increasing arrhythmia risk.
What this interaction means in plain words
Hydrocortisone and Terfenadine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Corticosteroid-induced hypokalemia may add to the QT-related risk of terfenadine.
What to do
Prefer a non-sedating antihistamine without QT liability, such as fexofenadine, and check potassium if systemic steroids are used.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Hydrocortisone
- Hydrocortisone + Mifepristone Contraindicated
- Hydrocortisone + Poliovirus vaccine live oral trivalent Contraindicated
- Hydrocortisone + Smallpox vaccine live Contraindicated
- Adenovirus types 4 and 7 live + Hydrocortisone Major
- Aldesleukin + Hydrocortisone Major
- Aspirin + Hydrocortisone Major
Frequently asked questions
Can I take Hydrocortisone with Terfenadine?
MediHelp rates the interaction as moderate. Hydrocortisone and Terfenadine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Terfenadine is withdrawn or contraindicated with CYP3A4 inhibitors because of QT prolongation and torsades de pointes. Hydrocortisone is not a significant CYP3A4 inhibitor, and the main concern is corticosteroid-related hypokalemia increasing arrhythmia risk.
How serious is the interaction between Hydrocortisone and Terfenadine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer a non-sedating antihistamine without QT liability, such as fexofenadine, and check potassium if systemic steroids are used.
What other medicines interact with Hydrocortisone?
MediHelp also lists interactions of Hydrocortisone with, for example, Mifepristone, Poliovirus vaccine live oral trivalent, Smallpox vaccine live. The full list is on the Hydrocortisone page.
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