Drug interactions
Chlorthalidone + Fosinopril-hydrochlorothiazide
Severity: Major
Chlorthalidone and Fosinopril-hydrochlorothiazide: 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
Chlorthalidone is a thiazide-like diuretic, so adding it to a regimen containing hydrochlorothiazide duplicates therapy. This increases the risk of hypokalemia, hyponatremia, hypomagnesemia, volume depletion and hyperuricemia with little added benefit.
What this interaction means in plain words
Chlorthalidone and Fosinopril-hydrochlorothiazide 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; Fosinopril-hydrochlorothiazide belongs to Cardiovascular.
Why it happens
Duplicate inhibition of the sodium-chloride cotransporter in the distal tubule causing additive diuresis and electrolyte loss.
What to do
Avoid using two thiazide-type diuretics together and keep a single agent. Check electrolytes and renal function if the overlap has occurred.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Chlorthalidone and Fosinopril-hydrochlorothiazide, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
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 Chlorthalidone
Frequently asked questions
Can I take Chlorthalidone with Fosinopril-hydrochlorothiazide?
MediHelp rates the interaction as major. Chlorthalidone and Fosinopril-hydrochlorothiazide 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 regimen containing hydrochlorothiazide duplicates therapy. This increases the risk of hypokalemia, hyponatremia, hypomagnesemia, volume depletion and hyperuricemia with little added benefit.
How serious is the interaction between Chlorthalidone and Fosinopril-hydrochlorothiazide?
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 using two thiazide-type diuretics together and keep a single agent. Check electrolytes and renal function if the overlap has occurred.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
