Abstract
We measured serum concentrations of Oxatomide, M-11 (active metabolite of Oxatomide), and M-5 (inactive metabolite of Oxatomide) by HPLC in 6 asthmatic patients medicated with 1mg/kg/day twice daily of Oxatomide, and examined the relationship between their concentrations and the clinical efficacy of Oxatomide. Serum concentrations of Oxatomide, M-11, and M-5 after 2-4 hours of medication were 5.5-16.0ng/ml, 4.5-44.3ng/ml, and 0.5-44.2ng/ml, respectively. There were significant negative correlations between the serum concetration of M-11 or the sum of serum concetrations of Oxatomide and M-11, and the clinical asthma score, respectively. However, there were no significant correlations between the serum concentrations of Oxatomide and M-5, and the clinical asthma score, respectively. It might be useful to examine the serum concentrations of active forms of Oxatomide in vivo, M-11 and Oxatomide, simultaneously, when the clinical effect of Oxatomide in asthmatic patients is estimated.
