tokens: Positive linear correlations were found when the AUC ( 0 - 12 ) ( r = 0 . 68 ; P less than 0 . 01 ) , the maximum plasma concentration ( r = 0 . 34 ; P less than 0 . 01 ) , the minimum plasma concentration ( r = 0 . 55 ; P less than 0 . 01 ) , and the elimination t1 / 2 ( r = 0 . 46 ; P less than 0 . 01 ) were regressed with age .