Question:

I am being treated for high blood pressure. I use Dynacirc, Lisinopril, and Toprol. Are there any diuretics available which are not related to Thiazides or Lasix, as I am allergic to sulfa drugs?

Answer:

Patients who report a “sulfa” allergy are generally referring to a previous reaction to a sulfonamide antibiotic drug. Other sulfonamide drug classes such as diuretics have different chemical structures.

The incidence of cross allergenicity between these classes of sulfonamides is low due to the chemical differences in the drugs as well as differences in drug processing or metabolism in the body. This means if you had a previous allergy to a sulfonamide antibiotic drug you may not have an allergy to a sulfonaminde nonantibiotic drug.

If your reaction to sulfonamide antibiotic was mild with rash and itching, another sulfonamide drug class can probably be used. If your reaction to the sulfonamide antibiotic was serious or if you have many allergies, using another sulfonamide drug is probably not advisable.

The Food and Drug Administration (FDA) recommends that fursemide be used with caution in a patient with a sulfonamide allergy. The FDA advises that hydrochlorothiazide is contraindicated in a sulfonamide allergic patient. Some sources recommend a reduced dose be given under medical supervision.

Ethacrynic acid (Edecrin) is a diuretic that doesn’t contain a sulfa group and is a possible alternative.

Please discuss your sulfa allergy and your concerns about the diruetics with you family physician.

Reference:  The Pharmacist’s Letter
                 Jeff M.Jellin PharmD,  Editor
                 detail document 211113

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