Tidd M J, Ramsay L E, Shelton J R, Palmer R F
Int J Clin Pharmacol Biopharm. 1977 May;15(5):205-10.
Data showing a linear relationship between spironolactone dose and the levels of canrenone in plasma and urine are presented to support the use of canrenone levels as a measure of the bioavailability of spironolactone. The bioavailability of a selected batch of spironolactone 25 mg tablets was compared to that of an oral aqueous suspension of spironolactone in a separate balanced cross-over study involving 10 healthy subjects. The tablets were equivalent to suspension as regards area under the plasma concentration-time curve and total urinary excretion of canrenone, the prinicipal unconjugated metabolite of spironolactone. Peak plasma concentrations of canrenone were higher, and were attained significantly earlier, after treatment with spironolactone in suspension. The results indicate that spironolactone was absorbed more rapidly from the suspension, but that the total absorption did not differ between the two formulations.
有数据表明，螺内酯剂量与血浆及尿液中坎利酮水平之间呈线性关系，以此支持将坎利酮水平作为衡量螺内酯生物利用度的指标。在一项涉及10名健康受试者的单独的平衡交叉研究中，将一批选定的25毫克螺内酯片剂的生物利用度与螺内酯口服水混悬液的生物利用度进行了比较。就血浆浓度-时间曲线下面积以及螺内酯主要的未结合代谢产物坎利酮的总尿排泄量而言，片剂与混悬液相当。服用螺内酯混悬液后，坎利酮的血浆峰值浓度更高，且达到峰值的时间明显更早。结果表明，螺内酯从混悬液中的吸收更快，但两种制剂的总吸收量并无差异。
