Patients who are allergic to sulfa and require a diuretic (“water”) pill have several options.
In general, the sulfa contained in antibiotic drugs has a slightly different chemical structure than the sulfa compounds found in diuretics. As a result, people who are allergic to sulfa antibiotics may be able to take a sulfa-containing diuretic without experiencing a reaction. For patients who are allergic to sulfa-containing diuretics, doctors sometimes prescribe triamterene, spironolactone, amiloride, or ethacrynic acid. These diuretic medications do not contain sulfa. The first three may require monitoring of blood potassium levels, especially when given in combination with other blood pressure medications.