idiosyncratic reaction

English

Noun

idiosyncratic reaction (plural idiosyncratic reactions)

  1. (pharmacy, medicine) A reaction to a medication that is unusual and unpredictable, specific to a particular person. Unlike allergy, it can occur on first exposure to the medication; unlike a side effect, it affects only very few individuals.
    • 2001, Margaret Fordham, “The Standard of Care Applicable to Practitioners of Alternative Medicine: Shakoor v Situ”, in Singapore Journal of Legal Studies[1], page 4:
      The conclusion was that Mr Shakoor had experienced a rare and unpredictable idiosyncratic reaction to them.