Are allergic effects from medications predictable and dose-related?

Allergic effects from medications are generally not predictable and are not dose-related. Unlike side effects, which often occur at specific doses and can be anticipated based on the pharmacology of the drug, allergic reactions are the result of an individual's immune response to a substance. This means that an allergic reaction can occur in some individuals after exposure to a medication, but others may never experience such a reaction, regardless of dose or duration of exposure.

The unpredictable nature of allergic reactions is due to various factors, including genetic predispositions, previous sensitization to allergens, and the immune system's particular response to specific proteins or compounds in the medication. Consequently, the occurrence of allergic reactions can vary widely among patients, making them distinct from dose-dependent side effects.