Hypersensitivity reactions to anthranilic acid derivatives

Area of Science:

• Pharmacology
• Immunology
• Drug Hypersensitivity

Background:

• Anthranilic acid derivatives, including glafenine and fenamates, are nonsteroidal anti-inflammatory drugs (NSAIDs).
• Adverse drug reactions can range from mild to severe, necessitating careful diagnosis and management.
• Understanding drug hypersensitivity is crucial for patient safety and therapeutic efficacy.

Observation:

• A patient experienced immediate adverse reactions to glafenine and meclofenamate sodium.
• Skin testing revealed positive intradermal reactions to glafenine and meclofenamate bound to human serum albumin (HSA).
• Oral challenge confirmed hypersensitivity to glafenine, meclofenamate, and mefenamic acid, while tolerating other NSAIDs.

Findings:

• The patient exhibited selective hypersensitivity to specific anthranilic acid derivatives.
• Intradermal tests with drug-HSA conjugates were positive, suggesting an immune-mediated response.
• Leukocyte histamine release and RAST assays were negative, indicating a non-anaphylactic immunologic mechanism.

Implications:

• This case highlights a rare instance of selective NSAID hypersensitivity.
• The findings suggest an immunologic mechanism and potential cross-reactivity among anthranilic acid derivatives.
• Further research is needed to elucidate the specific mechanisms underlying such selective drug reactions.