Which statement best describes Type B ADRs?

Which statement best describes Type B ADRs?

• A. They are predictable with high doses
• B. They are related to cumulative dose
• C. They are unpredictable and often immunologic or idiosyncratic
• D. They are always dose-related and common

Answer: (C)

Unpredictable and not dose-related. Type B adverse drug reactions arise in a minority of individuals due to immune-mediated processes or unusual, idiosyncratic metabolic factors. They can occur at any dose and may show up after first exposure or after some time, often requiring stopping the drug and managing the reaction. This contrasts with dose-dependent reactions, which are predictable from pharmacology and typically worsen with higher doses, and with reactions tied to cumulative dose. Because of their unpredictable nature and potential severity, these reactions are not common and cannot be reliably anticipated by looking at the dose.

Unpredictable and not dose-related. Type B adverse drug reactions arise in a minority of individuals due to immune-mediated processes or unusual, idiosyncratic metabolic factors. They can occur at any dose and may show up after first exposure or after some time, often requiring stopping the drug and managing the reaction. This contrasts with dose-dependent reactions, which are predictable from pharmacology and typically worsen with higher doses, and with reactions tied to cumulative dose. Because of their unpredictable nature and potential severity, these reactions are not common and cannot be reliably anticipated by looking at the dose.