Thiazide diuretic
Hydrochlorothiazide and grapefruit: a real interaction?
Grapefruit is famous as the juice that interacts with medications, and the warning is real for a number of drugs. Whether it matters specifically for Hydrochlorothiazide (Hydrochlorothiazide) at 12.5mg, 25mg, 50mg depends on whether the active ingredient Hydrochlorothiazide is metabolised by CYP3A4 in the gut wall and how much that pathway contributes to first-pass metabolism.
The CYP3A4 mechanism
Grapefruit (and its juice) inhibits CYP3A4 enzymes in the gut wall, increasing the absorbed dose of medications metabolised by that enzyme. For drugs in the Thiazide diuretic class that go through CYP3A4 first-pass metabolism, regular grapefruit consumption can raise plasma levels of Hydrochlorothiazide by a clinically meaningful margin and amplify side effects.
What to do with Hydrochlorothiazide
According to the prescribing information for Hydrochlorothiazide, if grapefruit is flagged as an interaction, the safest practice is to avoid grapefruit entirely or to discuss timing with the prescriber. Hydrochlorothiazide blocks the sodium-chloride symporter in the distal convoluted tubule of the kidney, reducing sodium reabsorption and producing modest diuresis. A small occasional serving may be tolerable; daily large servings around the time of Hydrochlorothiazide dosing are not recommended at 12.5mg, 25mg, 50mg.
Frequently asked questions
Can I eat grapefruit while on Hydrochlorothiazide? ▾
For some Thiazide diuretic medications, grapefruit is best avoided or limited because of CYP3A4 inhibition. Whether Hydrochlorothiazide specifically is affected depends on Hydrochlorothiazide; the prescribing information lists this. When in doubt, ask the pharmacist or check the patient leaflet.
How much grapefruit is too much with Hydrochlorothiazide? ▾
For drugs where the interaction matters, even modest daily grapefruit intake (one whole grapefruit or one large glass of juice) can shift drug levels noticeably. For Hydrochlorothiazide at 12.5mg, 25mg, 50mg, individual tolerance varies; the cautious choice is to avoid grapefruit if any interaction is mentioned.
Products containing Hydrochlorothiazide
More on Hydrochlorothiazide
- With alcoholHydrochlorothiazide and alcohol — is it safe to drink?
- With foodShould Hydrochlorothiazide be taken with food?
- Side effectsHydrochlorothiazide side effects: common, rare and warning signs
- Dosage guideHydrochlorothiazide dosage guide: how much to take and when
- OnsetHow fast does Hydrochlorothiazide start working?
- DurationHow long does Hydrochlorothiazide last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.