Drug interactions
Enalapril-hydrochlorothiazide + Quinidine
Severity: Major
Enalapril-hydrochlorothiazide and Quinidine: 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
Quinidine is a cation that may compete with hydrochlorothiazide for renal tubular secretion. More importantly, thiazide-induced hypokalemia or hypomagnesemia increases the risk of QT prolongation and torsades de pointes with quinidine.
What this interaction means in plain words
Enalapril-hydrochlorothiazide and Quinidine 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.
Enalapril-hydrochlorothiazide belongs to Cardiovascular; Quinidine belongs to Anti Parasitic.
Why it happens
Electrolyte depletion from the thiazide potentiates quinidine QT prolongation, with possible competition for renal tubular secretion.
What to do
Check and correct potassium and magnesium before and during therapy, and monitor ECG for QT prolongation. Consider an alternative diuretic or antiarrhythmic if electrolytes cannot be kept normal.
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 Enalapril-hydrochlorothiazide
- Aliskiren + Enalapril-hydrochlorothiazide Contraindicated
- Dofetilide + Enalapril-hydrochlorothiazide Contraindicated
- Enalapril-hydrochlorothiazide + Protein a column Contraindicated
- Enalapril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Amifostine + Enalapril-hydrochlorothiazide Major
- Amiloride + Enalapril-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 Enalapril-hydrochlorothiazide with Quinidine?
MediHelp rates the interaction as major. Enalapril-hydrochlorothiazide and Quinidine 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. Quinidine is a cation that may compete with hydrochlorothiazide for renal tubular secretion. More importantly, thiazide-induced hypokalemia or hypomagnesemia increases the risk of QT prolongation and torsades de pointes with quinidine.
How serious is the interaction between Enalapril-hydrochlorothiazide and Quinidine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check and correct potassium and magnesium before and during therapy, and monitor ECG for QT prolongation. Consider an alternative diuretic or antiarrhythmic if electrolytes cannot be kept normal.
What other medicines interact with Enalapril-hydrochlorothiazide?
MediHelp also lists interactions of Enalapril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Protein a column. The full list is on the Enalapril-hydrochlorothiazide page.
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