The effect of valdecoxib (40 mg, PO) and placebo on cold- (panel A) and hot (panel B) pain threshold. The pain threshold is expressed in °C (mean ± SD). Time scale indicates the time (in min) after study drug or placebo administration and when the pain measurements were performed. Black columns represent valdecoxib administration; white columns represent placebo administration. The results were compared using the Wilcoxon signed ranks test.