Summary

FDA has received reports of allergic-type reactions potentially related to sulfite-containing compounded drugs. FDA is alerting health care professionals, compounders and patients about the risk of potentially serious allergic-type reactions to sulfite-containing compounded drugs. FDA recognizes that health care professionals and patients may be unaware of sulfite allergies or sensitivities. 

FDA encourages patients with known sulfite allergies or sensitivities to discuss them with their health care professional. Patients and health care professionals, using or prescribing compounded drugs, can also ask compounders about the presence of sulfites in the drugs they compound especially when there are concerns about sulfite allergies or sensitivities. FDA also encourages compounders to indicate the presence of sulfites on product labels, and/or include a sulfite warning statement, to minimize the risk of adverse reactions in individuals with a sulfite allergy or sensitivity.

Background

Sulfites are substances that may be added to certain drug products as preservatives, to help prevent the active drug ingredient from breaking down and becoming less effective. Examples of specific sulfites include:

• sodium bisulfite
• sodium metabisulfite
• sodium sulfite
• potassium bisulfite
• potassium metabisulfite

Studies have demonstrated that sulfites may cause allergic-type reactions in susceptible people, especially patients with asthma. Allergic-type reactions may include anaphylactic symptoms and life-threatening or less severe asthmatic episodes in susceptible people.1 

FDA-approved prescription drugs containing sulfites are required to include a warning statement in the product labeling. 

Adverse Event Summary and Risk Discussion

FDA has received adverse event reports indicating allergic or allergic-type reactions potentially related to sulfite-containing compounded drugs, including compounded drugs for ophthalmic routes of administration. These reports include: 

• complaints of conjunctivitis (pink eye)
• itchy eyesswollen eyelids
• respiratory failure (breathing difficulty with low blood oxygen)

Sulfites may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in susceptible people.¹

FDA encourages patients and health care professionals with concerns about sulfite allergies or sensitivities to ask compounders about the presence of sulfites in the drugs they compound to minimize the risk of adverse reactions. FDA also encourages compounders to indicate the presence of sulfites on product labels and/or include a sulfite warning statement, as this could help reduce the risk of adverse reactions in people with sulfite allergies or sensitivities. 

Compounded drugs are not FDA-approved, which means FDA has not evaluated their safety, effectiveness, quality or labeling prior to marketing. 

Individuals with a sulfite allergy or sensitivity may be exposed to sulfites and may risk experiencing an allergic or allergic-type reaction if they are unaware of the presence of sulfites and the presence of sulfites is not indicated on the label of a compounded drug they use. FDA recommends that patients, health care professionals and compounders be aware of potential safety risks associated with the use of sulfite-containing compounded drugs. 

Report Adverse Events to FDA

FDA encourages patients, health care professionals and compounders to report adverse events or quality problems experienced with the use of compounded drugs to FDA’s MedWatch Adverse Event Reporting program:

• Complete and submit the report online at MedWatch: The FDA Safety Information and Adverse Event Reporting Program or
• Download and complete the form, then submit it via fax at 1-800-FDA-0178.

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References

¹ CFR - Code of Federal Regulations Title 21. Sec. 201.22. Prescription drugs containing sulfites. Accessed May 29, 2024. Available at the Code of Federal Regulations website.