Effects of randomized treatments on TX biosynthesis in vivo and ex vivo in ET patients. (A-B) Box-whisker plots of urinary TXM excretion values in ET patients before (visit 1) and after (visit 2) 1 week of randomized treatment with etoricoxib 90 mg daily added to low-dose aspirin (A) or low-dose aspirin alone (B). (C-D) Serum TXB₂ values in patients before (visit 1) and after (visit 2) randomization to etoricoxib addition (C) or low-dose aspirin continuation (D). *P < .05 versus visit 1. The horizontal dotted line in each panel represents the median values previously reported by our group in healthy subjects taking 100 mg of aspirin daily,³²  and namely in these subjects serum TXB₂ median was 1.18 [IQR 0.52-2.38] ng/mL (n = 120 determinations), while urinary TXM median was 135.5 [IQR 106-170] pg/mg creatinine (n = 120 determinations).