Allergic reactions to small-molecule drugs: Will we move from reaction to prediction?

This primer provides background and an update on immune mechanisms which allow small-molecule drugs to trigger drug allergy.

For many years, understanding of drug allergy was limited. The hapten model of drug allergy applies only to a subset of drugs known to cause allergic reactions. More recently, the understanding of immune reactions has expanded to include pharmacologic interactions with the molecules involved in immune identity and surveillance. These insights are presented and discussed here.

Greater understanding of allergic reactions to drugs offers the promise to move from a position of reacting to immune reactions to a more proactive model. This may translate to new opportunities to characterize risk in drug development, confirm the nature of reactions in clinical settings, enhance the targeting of alerts, and ultimately to allow patient-specific prediction.