Screening of Antipyretic Drugs

Definition, scope & rationale

• What is screened — an experimental / methodology topic — antipyretic screening is the in-vivo evaluation of a candidate compound's ability to lower an artificially raised (febrile) core temperature toward normal, without lowering normothermic temperature (which would flag a non-specific hypothermic, not antipyretic, action).
• Two obligatory steps — every assay has (i) induction of experimental pyrexia by injecting a pyrogen, then (ii) measurement of the antipyretic time-course — the fall in rectal/core temperature after the test drug versus a febrile untreated control.
• Rationale — antipyretic activity is one arm of the classical NSAID analgesic–antipyretic–anti-inflammatory triad; for an anti-inflammatory candidate, demonstrable antipyresis is regarded as a confirmatory positive side-effect expected of a COX-inhibiting molecule, so the assay is routinely run alongside analgesic and anti-inflammatory screens.
• Topic boundary — this covers antipyretic screening only — induction of fever and its pharmacological reversal; analgesic (nociceptive-threshold) and anti-inflammatory (oedema/exudate) screens are separate assays referenced here only where the shared reagent (brewer's yeast) or COX/PGE₂ mechanism links them.