Drug interactions
Captopril-hydrochlorothiazide + Potassium phosphates
Severity: Major
Captopril-hydrochlorothiazide and Potassium phosphates: 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
Potassium phosphates, particularly intravenous, can rapidly raise serum potassium, and captopril reduces potassium excretion. Severe hyperkalemia with cardiac effects may occur, especially in renal impairment.
What this interaction means in plain words
Captopril-hydrochlorothiazide and Potassium phosphates 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.
Why it happens
Exogenous potassium load combined with ACE inhibitor-induced reduction in aldosterone and renal potassium excretion.
What to do
Monitor serum potassium and ECG when given intravenously, and use slow infusion rates with dose reduction in renal impairment. Check potassium and phosphate regularly during oral use.
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 Captopril-hydrochlorothiazide
- Aliskiren + Captopril-hydrochlorothiazide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aceclofenac + Captopril-hydrochlorothiazide Major
- Aldesleukin + Captopril-hydrochlorothiazide Major
- Amifostine + Captopril-hydrochlorothiazide Major
Frequently asked questions
Can I take Captopril-hydrochlorothiazide with Potassium phosphates?
MediHelp rates the interaction as major. Captopril-hydrochlorothiazide and Potassium phosphates 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. Potassium phosphates, particularly intravenous, can rapidly raise serum potassium, and captopril reduces potassium excretion. Severe hyperkalemia with cardiac effects may occur, especially in renal impairment.
How serious is the interaction between Captopril-hydrochlorothiazide and Potassium phosphates?
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 ECG when given intravenously, and use slow infusion rates with dose reduction in renal impairment. Check potassium and phosphate regularly during oral use.
What other medicines interact with Captopril-hydrochlorothiazide?
MediHelp also lists interactions of Captopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Sacubitril / valsartan. The full list is on the Captopril-hydrochlorothiazide page.
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