Utility and sensitivity of the sore throat pain model: results of a randomized controlled trial on the COX-2 selective inhibitor valdecoxib.

The sore throat pain model was employed in this randomized, placebo-controlled trial to examine the sensitivity of the model in testing the efficacy of valdecoxib as an acute analgesic drug. Changes were made to the study design by employing a different diagnostic index for tonsillo-pharyngitis, a different rating scale (derived from Lasagna's pain thermometer), and alternative analyses, individual responder rates. Under double-blind conditions, 197 patients with painful pharyngitis were randomly allocated to valdecoxib 20 mg bid (n = 65), valdecoxib 40 mg qd (n = 66), or placebo (n = 66) for 24 hours. The expanded Tonsillo-Pharyngitis Assessment and the Lasagna Pain Scale were validated as sensitive study instruments. Both dosage regimens provided significantly greater pain relief compared with placebo on standard efficacy measures over the 24-hour study (all P < .05). Tests for individual response (eg, percentage of patients with at least moderate relief) confirmed these results, and other response rates identified the high sensitivity of the model itself (eg, only 5% of placebo-treated patients achieved >or=50% of maximum total pain relief over 6 hours). These findings indicate that sore throat is a sensitive model to assess analgesic efficacy.