Drug interactions
Fosinopril-hydrochlorothiazide + Quinidine
Severity: Moderate
Fosinopril-hydrochlorothiazide and Quinidine: 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
Quinidine may compete with hydrochlorothiazide for renal tubular secretion, but the clinical effect is small. A more relevant concern is that thiazide-induced hypokalemia or hypomagnesemia can increase the QT-prolonging and proarrhythmic risk of quinidine.
What this interaction means in plain words
Fosinopril-hydrochlorothiazide and Quinidine 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.
Fosinopril-hydrochlorothiazide belongs to Cardiovascular; Quinidine belongs to Anti Parasitic.
Why it happens
Thiazide-induced hypokalemia and hypomagnesemia potentiate quinidine QT prolongation, with minor competition for renal tubular cation secretion.
What to do
Monitor serum potassium and magnesium and correct deficits; obtain an ECG if QT-prolonging risk is elevated.
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 Fosinopril-hydrochlorothiazide
- Aliskiren + Fosinopril-hydrochlorothiazide Contraindicated
- Dofetilide + Fosinopril-hydrochlorothiazide Contraindicated
- Fosinopril-hydrochlorothiazide + Protein a column Contraindicated
- Fosinopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aldesleukin + Fosinopril-hydrochlorothiazide Major
- Amifostine + Fosinopril-hydrochlorothiazide Major
Other interactions of Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine Contraindicated
Frequently asked questions
Can I take Fosinopril-hydrochlorothiazide with Quinidine?
MediHelp rates the interaction as moderate. Fosinopril-hydrochlorothiazide and Quinidine 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. Quinidine may compete with hydrochlorothiazide for renal tubular secretion, but the clinical effect is small. A more relevant concern is that thiazide-induced hypokalemia or hypomagnesemia can increase the QT-prolonging and proarrhythmic risk of quinidine.
How serious is the interaction between Fosinopril-hydrochlorothiazide and Quinidine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor serum potassium and magnesium and correct deficits; obtain an ECG if QT-prolonging risk is elevated.
What other medicines interact with Fosinopril-hydrochlorothiazide?
MediHelp also lists interactions of Fosinopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Protein a column. The full list is on the Fosinopril-hydrochlorothiazide page.
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