No correlations between the urinary ratio of 6 beta-hydroxycortisol to free cortisol and pharmacokinetics of alprazolam. - Furukori,Y.N.; Kondo,T.; Kubota,T.; Otake,H.; Ohkubo,T.; Nagasaki,T.; Sugawara,K.; Chiba,K.; Otani,K.; Kaneko,S. (Eur J Clin Pharmacol, 2001)