Drug interactions
Furosemide + Hydrochlorothiazide
Severity: Moderate
Furosemide and Hydrochlorothiazide: moderate 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
Combining a thiazide with a loop diuretic produces sequential nephron blockade, giving a strong diuretic response. This can cause marked hypokalemia, hyponatremia, hypomagnesemia, volume depletion and renal impairment.
What this interaction means in plain words
Furosemide and Hydrochlorothiazide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Furosemide belongs to Cardiovascular; Hydrochlorothiazide belongs to Cardiovascular.
Why it happens
Blockade of sodium reabsorption at both the loop of Henle and the distal tubule increases distal sodium delivery and potassium and magnesium excretion.
What to do
Monitor electrolytes, renal function, weight and blood pressure closely, particularly in the first days of combined therapy. Replace potassium and magnesium and reduce diuretic doses if volume depletion develops.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Hydrochlorothiazide
Other interactions of Furosemide
- Amifostine + Furosemide Major
- Amikacin + Furosemide Major
- Carbenoxolone + Furosemide Major
- Cephaloridine + Furosemide Major
- Cisplatin + Furosemide Major
- Digoxin + Furosemide Major
Frequently asked questions
Can I take Furosemide with Hydrochlorothiazide?
MediHelp rates the interaction as moderate. Furosemide and Hydrochlorothiazide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Combining a thiazide with a loop diuretic produces sequential nephron blockade, giving a strong diuretic response. This can cause marked hypokalemia, hyponatremia, hypomagnesemia, volume depletion and renal impairment.
How serious is the interaction between Furosemide and Hydrochlorothiazide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor electrolytes, renal function, weight and blood pressure closely, particularly in the first days of combined therapy. Replace potassium and magnesium and reduce diuretic doses if volume depletion develops.
What other medicines interact with Hydrochlorothiazide?
MediHelp also lists interactions of Hydrochlorothiazide with, for example, Dofetilide, Amifostine, Amiodarone. The full list is on the Hydrochlorothiazide page.
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