What type of reaction results from intense effects on target organs?

A toxic reaction occurs when a drug causes harmful effects that are severe or intense enough to result in damage to target organs. This type of reaction typically involves a greater magnitude of response than simply interfering with normal function, leading to significant physiological changes or damage. Toxic reactions can arise from an overdose, incorrectly prescribed dosages, or individual susceptibility to a particular medication, making them serious occurrences that require immediate attention.

In contrast, allergic effects, while potentially serious, result from an individual's immune response to a drug rather than direct damage to target organs. Side effects are generally milder, unintended responses to medication that do not necessarily cause harm or injury. Adverse reactions encompass a broader category that includes unwanted side effects as well as more severe responses, but they do not always indicate the intense, harmful nature that defines a toxic reaction.