What is an example of a Type C ADR?

• A. Adrenal suppression with corticosteroids
• B. Anaphylaxis to penicillin
• C. Carcinogenesis and teratogenesis
• D. Bleeding risk with anticoagulants

Answer: (A)

Type C adverse drug reactions are chronic toxic effects that appear after long-term exposure to a drug. The classic example is adrenal suppression that develops with prolonged systemic corticosteroid therapy. When corticosteroids are used for an extended period, they suppress the hypothalamic-pituitary-adrenal axis, reducing endogenous cortisol production. This reflects damage or dysfunction that accumulates over time due to sustained exposure, not an immediate, dose-related reaction or an acute immune response. If the drug is stopped abruptly, there can be a risk of adrenal insufficiency, illustrating why chronic exposure leads to this kind of adverse effect.

Anaphylaxis from penicillin is an immediate, immune-mediated reaction—not a chronic effect. Bleeding risk with anticoagulants is a predictable, often dose-related effect that can occur acutely. Carcinogenesis and teratogenesis are long-term risks, but adrenal suppression remains the clearest example of a Type C chronic effect tied to sustained use of a drug like corticosteroids.