Allopurinol and Ethacrynic acid interaction
Allopurinol and Ethacrynic acid: the Allopurinol prescribing label describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Allopurinol label · effective 2026-05-21
Hypersensitivity reactions to allopurinol tablets may be increased in patients with decreased kidney function receiving thiazide diuretics and allopurinol tablets concurrently.
The following drugs may increase the risk of serious skin reactions: bendamustine, thiazide diuretics, ampicillin and amoxicillin.
Drugs Known to Affect the Occurrence of Skin Rash and Hypersensitivity Concomitant use of the following drugs may increase the risk of skin rash, which may be severe: bendamustine, thiazide diuretics, ampicillin and amoxicillin.
Renal impairment may further increase risk with concomitant use of thiazide diuretics [ see Warnings and Precautions ( 5.1 , 5.2 ) and Clinical Pharmacology (12.2) ].
Monitor kidney function and reduce the dose of allopurinol tablets in patients with concomitant thiazide diuretic use and impaired renal function [ see Dosage and Administration ( 2.6 ), Warnings and Precautions ( 5.1 ) ].
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.