▁of ▁action ▁Like ▁any ▁other ▁select ive ▁CO X - 2 ▁in hib itor ▁(" co x ib "), ▁et or ico x ib ▁select ively ▁in hib its ▁is o form ▁ 2 ▁of ▁the ▁en zym e ▁cy clo ox y gen ase ▁( CO X - 2 ). ▁It ▁has ▁approximately ▁ 1 0 6 - fold ▁select ivity ▁for ▁CO X - 2 ▁in hib ition ▁over ▁CO X - 1 . ▁ ▁This ▁reduces ▁the ▁generation ▁of ▁prost ag land ins ▁( PG s ) ▁from ▁a rach id onic ▁acid . ▁ ▁Among ▁the ▁different ▁functions ▁ex ert ed ▁by ▁P G s , ▁their ▁role ▁in ▁the ▁infl amm ation ▁cas cade ▁should ▁be ▁highlight ed . ▁ ▁Select ive ▁CO X - 2 ▁in hib itors ▁show ▁less ▁activity ▁on ▁CO X - 1 ▁compared ▁to ▁traditional ▁non - st ero idal ▁anti - infl am mat ory ▁dru gs ▁( NS A ID ). ▁This ▁reduced ▁activity ▁is ▁the ▁cause ▁of ▁reduced ▁g astro int est inal ▁side ▁effects , ▁as ▁demonstrated ▁in ▁several ▁large ▁clin ical ▁tri als ▁performed ▁with ▁different ▁co x ib s . ▁ ▁History ▁Some ▁clin ical ▁tri als ▁and ▁meta - analysis ▁showed ▁that ▁treatment ▁with ▁some ▁co x ib s ▁( in ▁particular ▁ro f ec ox ib ) ▁led ▁to ▁increased ▁inc idence ▁of ▁ad verse ▁card i ov asc ular ▁events ▁compared ▁to ▁place bo . ▁Because ▁of ▁these ▁results , ▁some ▁dru gs ▁were