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Intermediate Technical IVT

paradoxical reaction

Unexpected opposite response to medication, such as increased agitation from sedatives in elderly or brain-injured patients.

Full Definition

Paradoxical reaction refers to an unexpected therapeutic response that is opposite to the intended pharmacological effect of a medication. This phenomenon is particularly common in neuropsychiatric populations, especially elderly patients, those with dementia, or individuals with brain injury. Examples include increased agitation or disinhibition from benzodiazepines intended to provide sedation, or hyperactivity from antihistamines meant to cause drowsiness. These reactions may be dose-dependent and can significantly complicate treatment planning. Clinical documentation must carefully distinguish paradoxical reactions from treatment failure or underlying disease progression to guide appropriate medication adjustments.

Usage

Usage note: Specify the medication and unexpected response; distinguish from treatment failure or disease progression.

In Context

  • "The elderly patient experienced a paradoxical reaction to lorazepam, becoming more agitated rather than sedated." — Medication adjustment documentation
  • "Given the patient's history of paradoxical reactions to benzodiazepines, alternative anxiolytics were considered." — Treatment planning notes

Also known as

paradoxical drug response

Contrasted with

expected therapeutic response

Don't confuse with

treatment failure disease progression

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