Drug interactions
Grapefruit + Hydrochlorothiazide-losartan
Severity: Minor
Grapefruit and Hydrochlorothiazide-losartan: minor 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
Grapefruit inhibits intestinal CYP3A4, which could slightly reduce formation of losartan's active metabolite. Because CYP2C9 is the main activating pathway, the effect on blood pressure is generally small.
What this interaction means in plain words
Grapefruit and Hydrochlorothiazide-losartan have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Inhibition of CYP3A4 reduces conversion of losartan to its active carboxylic acid metabolite.
What to do
No routine change is needed; monitor blood pressure if large amounts of grapefruit juice are consumed regularly.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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
Frequently asked questions
Can I take Grapefruit with Hydrochlorothiazide-losartan?
MediHelp rates the interaction as minor. Grapefruit and Hydrochlorothiazide-losartan have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Grapefruit inhibits intestinal CYP3A4, which could slightly reduce formation of losartan's active metabolite. Because CYP2C9 is the main activating pathway, the effect on blood pressure is generally small.
How serious is the interaction between Grapefruit and Hydrochlorothiazide-losartan?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine change is needed; monitor blood pressure if large amounts of grapefruit juice are consumed regularly.
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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