Adverse Drug Reaction (ADR) can be described as which of the following?

• A. Can be predictable or unpredictable
• B. Always dangerous
• C. Never occurs
• D. Only occurs with certain drugs

Answer: (A)

Adverse drug reactions arise when a medication causes a harmful or unintended effect at normal doses, and they come in two main forms: predictable, dose-related reactions and unpredictable, idiosyncratic reactions. This means some ADRs can be anticipated based on how the drug works and the amount given, while others occur unpredictably in certain individuals regardless of dose. That combination is why the description that ADRs can be predictable or unpredictable is the most accurate. Remember, ADRs aren’t always dangerous—many are mild or dose-dependent—and they don’t occur only with a few drugs; they can happen with a wide range of medications.