Petereit L B, Meikle A W
Clin Pharmacol Ther. 1977 Dec;22(6):912-6. doi: 10.1002/cpt1977226912.
The effects of diphenylhydantoin (DPH) on the clearance of prednisolone from plasma, its bioavailability, and its biologic effectiveness were studied in 5 persons before and after daily DPH therapy for more than 3 wek. DPH decreased the mean half-time of disappearance of prednisolone from plasma by 45% and increased its metabolic clearance rate by an average of 77%. The gastrointestinal absorption of prednisolone and its first-pass clearance through splanchnic tissues were not significantly altered by DPH. The mean oral midnight dose of prednisolone required to suppress the 8 A.M. plasma level of cortisol to 5 microgram/dl was doubled following treatment of DPH. The increment in dose of prednisolone varied from 58% to 260% in the five individuals.
在5名受试者中，研究了苯妥英（DPH）对泼尼松龙从血浆中的清除率、生物利用度及其生物学效应的影响，这些受试者在每日接受DPH治疗超过3周前后进行了相关研究。DPH使泼尼松龙从血浆中消失的平均半衰期缩短了45%，并使其代谢清除率平均提高了77%。DPH对泼尼松龙的胃肠道吸收及其通过内脏组织的首过清除率没有显著影响。在接受DPH治疗后，将上午8点的皮质醇血浆水平抑制至5微克/分升所需的泼尼松龙平均口服午夜剂量增加了一倍。在这5名个体中，泼尼松龙剂量的增加幅度从58%到260%不等。
