From the Guidelines
Yes, several of the medications mentioned are sulfa drugs, including thiazide and loop diuretics, glyburide, glipizide, dapsone, and sulfasalazine, which all contain a sulfonamide chemical structure that can cause allergic reactions in susceptible individuals. According to the most recent and highest quality study, 1, these medications contain sulfonamide groups, which are responsible for their therapeutic effects but can also cause allergic reactions. The study notes that sulfonamide antimicrobials are structurally different from nonantimicrobial sulfonamides due to the presence of an aromatic amine group at the N4 position.
Some key points to consider when prescribing these medications include:
- Thiazide and loop diuretics, such as hydrochlorothiazide, chlorthalidone, furosemide, and bumetanide, contain sulfonamide groups, as do the oral hypoglycemic medications glyburide and glipizide, as reported in 1 and 1.
- Dapsone and sulfasalazine are also sulfa drugs, as noted in 1 and 1.
- Patients with sulfa allergies may experience reactions ranging from mild rashes to severe conditions like Stevens-Johnson syndrome when taking these medications.
- Cross-reactivity between different types of sulfa drugs varies, and healthcare providers should carefully evaluate a patient's specific allergy history before prescribing any sulfa-containing medication, as recommended in 1.
- Alternative treatments should be considered for those with documented severe sulfa allergies, as suggested in 1.
From the FDA Drug Label
The sulfonamides bear certain chemical similarities to some goitrogens, diuretics (acetazolamide and the thiazides), and oral hypoglycemic agents Sulfa drugs include sulfasalazine, and based on the chemical similarities, it can be inferred that:
- Diuretics such as acetazolamide and the thiazides are chemically similar to sulfa drugs.
- Oral hypoglycemic agents are also chemically similar to sulfa drugs, which may include glyburide and glipizide.
- There is no direct information about dapsone being a sulfa drug in this context, but it is known to be a sulfone antibiotic, which is related to sulfonamides. 2
From the Research
Diuretics and Sulfa Drugs
- The provided studies 3, 4, 5 discuss the use of diuretics in hypertension and their effectiveness, but do not mention whether diuretics are sulfa drugs.
- There is no information in the studies about glyburide, glipizide, dapsone, or sulfasalazine being classified as sulfa drugs in relation to diuretics.
Sulfa Drugs Classification
- The studies do not provide a classification of sulfa drugs or discuss the relationship between diuretics and sulfa drugs.
- It can be inferred that the studies focus on the clinical use and effectiveness of diuretics, rather than their chemical classification or relationship to sulfa drugs.