Drug interactions
Hydrochlorothiazide-losartan + Metformin
Severity: Moderate
Hydrochlorothiazide-losartan and Metformin: 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
Thiazides can raise blood glucose and so reduce metformin effectiveness. Volume depletion or reduced kidney function from the diuretic and losartan can also increase metformin accumulation and lactic acidosis risk.
What this interaction means in plain words
Hydrochlorothiazide-losartan and Metformin 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.
Hydrochlorothiazide-losartan belongs to Cardiovascular; Metformin belongs to Endocrine.
Why it happens
Thiazide-induced hyperglycemia opposes metformin, and reduced renal function or tubular competition may raise metformin exposure.
What to do
Monitor blood glucose and renal function, and adjust metformin dose according to eGFR. Hold metformin during dehydrating illness.
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-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 Metformin
Frequently asked questions
Can I take Hydrochlorothiazide-losartan with Metformin?
MediHelp rates the interaction as moderate. Hydrochlorothiazide-losartan and Metformin 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. Thiazides can raise blood glucose and so reduce metformin effectiveness. Volume depletion or reduced kidney function from the diuretic and losartan can also increase metformin accumulation and lactic acidosis risk.
How serious is the interaction between Hydrochlorothiazide-losartan and Metformin?
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 blood glucose and renal function, and adjust metformin dose according to eGFR. Hold metformin during dehydrating illness.
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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