Drug interactions
Chlorthalidone + Hydrochlorothiazide-losartan
Severity: Major
Chlorthalidone and Hydrochlorothiazide-losartan: 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
Chlorthalidone is a thiazide-like diuretic, so adding it to a product that already contains hydrochlorothiazide duplicates therapy. This increases the risk of hypokalemia, hyponatremia, hypotension, hyperuricemia and renal impairment.
What this interaction means in plain words
Chlorthalidone and Hydrochlorothiazide-losartan 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.
Chlorthalidone belongs to Cardiovascular; Hydrochlorothiazide-losartan belongs to Cardiovascular.
Why it happens
Duplicate inhibition of the distal tubular sodium-chloride cotransporter with additive electrolyte loss and volume depletion.
What to do
Avoid combining two thiazide-type diuretics; use one agent. If used deliberately, monitor sodium, potassium, and renal function closely.
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 Hydrochlorothiazide-losartan
- Aliskiren + Hydrochlorothiazide-losartan Contraindicated
- Dofetilide + Hydrochlorothiazide-losartan Contraindicated
- Hydrochlorothiazide-losartan + Sparsentan Contraindicated
- Aceclofenac + Hydrochlorothiazide-losartan Major
- Aldesleukin + Hydrochlorothiazide-losartan Major
- Amifostine + Hydrochlorothiazide-losartan Major
Other interactions of Chlorthalidone
Frequently asked questions
Can I take Chlorthalidone with Hydrochlorothiazide-losartan?
MediHelp rates the interaction as major. Chlorthalidone and Hydrochlorothiazide-losartan 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. Chlorthalidone is a thiazide-like diuretic, so adding it to a product that already contains hydrochlorothiazide duplicates therapy. This increases the risk of hypokalemia, hyponatremia, hypotension, hyperuricemia and renal impairment.
How serious is the interaction between Chlorthalidone and Hydrochlorothiazide-losartan?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining two thiazide-type diuretics; use one agent. If used deliberately, monitor sodium, potassium, and renal function closely.
What other medicines interact with Hydrochlorothiazide-losartan?
MediHelp also lists interactions of Hydrochlorothiazide-losartan with, for example, Aliskiren, Dofetilide, Sparsentan. The full list is on the Hydrochlorothiazide-losartan page.
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