Drug interactions
Hydrochlorothiazide-telmisartan + Quinidine
Severity: Major
Hydrochlorothiazide-telmisartan and Quinidine: major 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
Hydrochlorothiazide can cause hypokalemia and hypomagnesemia, which increase the risk of QT prolongation and torsades de pointes with quinidine. Thiazide-induced alkalinization of urine may also reduce quinidine excretion.
What this interaction means in plain words
Hydrochlorothiazide-telmisartan 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.
Hydrochlorothiazide-telmisartan belongs to Cardiovascular; Quinidine belongs to Anti Parasitic.
Why it happens
Diuretic-induced electrolyte depletion potentiates quinidine's QT-prolonging effect.
What to do
Monitor serum potassium and magnesium and correct deficits promptly. Obtain ECG monitoring for QT interval, especially at initiation.
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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Other interactions of Hydrochlorothiazide-telmisartan
- Aliskiren + Hydrochlorothiazide-telmisartan Contraindicated
- Dofetilide + Hydrochlorothiazide-telmisartan Contraindicated
- Hydrochlorothiazide-telmisartan + Sparsentan Contraindicated
- Aldesleukin + Hydrochlorothiazide-telmisartan Major
- Amifostine + Hydrochlorothiazide-telmisartan Major
- Amiloride + Hydrochlorothiazide-telmisartan 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 Hydrochlorothiazide-telmisartan with Quinidine?
MediHelp rates the interaction as major. Hydrochlorothiazide-telmisartan 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. Hydrochlorothiazide can cause hypokalemia and hypomagnesemia, which increase the risk of QT prolongation and torsades de pointes with quinidine. Thiazide-induced alkalinization of urine may also reduce quinidine excretion.
How serious is the interaction between Hydrochlorothiazide-telmisartan 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: Monitor serum potassium and magnesium and correct deficits promptly. Obtain ECG monitoring for QT interval, especially at initiation.
What other medicines interact with Hydrochlorothiazide-telmisartan?
MediHelp also lists interactions of Hydrochlorothiazide-telmisartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-telmisartan page.
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