Screening Methods for Anti-inflammatory & Analgesic Drugs

Scope, rationale & general principles

• What is screened — an experimental / methodology topic — the deliverable is the preclinical screening cascade used to detect & quantify analgesic, anti-inflammatory and antipyretic activity of a candidate molecule, NOT the clinical pharmacology of the drug classes.
• Two groups screened — (a) the narcotic / opioid (morphine) group — analgesia by a central CNS action; (b) the analgesic–antipyretic / NSAID group — central + peripheral action. Most NSAIDs are simultaneously analgesic, anti-inflammatory & antipyretic, so one candidate is run through all three axes.
• Cascade logic — preliminary in-vitro assays (receptor binding, enzyme inhibition, cell-based readouts) identify a lead → confirmed in in-vivo whole-animal models of acute, subacute & chronic inflammation / pain → only then clinical translation.
• Golden rule of analgesic testing — the drug is given before the noxious stimulus, so the assay measures its power to raise the threshold / minimal stimulus needed to elicit a nociceptive response, rather than reproducing established pathological pain.
• Translation caveat — Seok et al. (2013, PNAS) showed mouse inflammatory-disease models correlate poorly with human conditions → revised guidance favours rat over mouse, and findings should be reproduced in >1 mammalian species before extrapolation to man.