Sources/Uses
Used as preservatives in foods, beverages, and medications; Drugs containing sulfites may include parenteral steroids, antibiotics, cardiovascular drugs, and other intravenous medications; also peritoneal dialysis solutions, local anesthetics, radiocontrast dyes, and other drugs; Sulfites used as preservatives include sulfur dioxide, potassium metabisulfite, sodium sulfite, sodium metabisulfite, sodium bisulfite, and potassium bisulfite. [Ellenhorn, p. 1074]
Comments
An estimated 5% of patients with asthma are sulfite sensitive. Following sensitization, type-I immediate hypersensitivity reactions occur after ingestion. Reactions in asthmatics may occur without evidence of type-I, Ig-E mediation. Patients may present with one or more of the following: flushing, fainting, sneezing, urticaria, angioedema, abdominal distress, bronchospasm, and anaphylaxis. [Ellenhorn, p. 1074] Occupational asthma confirmed in a water plant worker and food workers exposed to sulfites in dust or solution used as a preservative; [Malo] Metabisulfites are preservatives used in wines, salad bars, fruits, juices, and shrimp. Onset of symptoms is within minutes. Common symptoms are flushing, low blood pressure, and bronchospasm. [Goldfrank, p. 676] Sulfites are among the drugs and toxins that cause bronchospasm (Table I-3) and anaphylactoid-like reactions (Table I-17). [Olson, p. 8, 28] Sulfites are not classifiable as to carcinogenicity to humans. [IARC] See "Potassium metabisulfite" for a documented case of occupational asthma. See agents in the category, "Sulfites."
Restricted
In 1987, the FDA withdrew approval for the use of sulfites in fresh vegetables. Prescription drugs containing sulfites and packaged foods containing sulfites >10 ppm must be labeled. [Ellenhorn, p. 1074]