The diuretic effect of furosemide in relation to its disposition in man.

Experiments concerning the diuretic effect and disposition of furosemide were performed in nine healthy male volunteers. During the test period, each of subject was given 50 ml of water every half an hour. Under this experimental condition, interesting phenomena, such as almost identical duration of diuretic effect independent of given dose and the so-called clockwise hysteresis of the concentration-effect curve were observed. These phenomena revealed that the body water regulation system had intervened in the pharmacodynamics of furosemide. Based on experimental results, a model and a new equation are presented, which describe the quantitative relationship of the drug disposition, the diuretic response and the body water regulatory function.