In medicine, the clearance is a measurement of the renal excretion ability. Although clearance may also involve other organs than the kidney, it is almost synonymous with renal clearance or renal plasma clearance. Each substance has a specific clearance that depends on its filtration characteristics. Clearance is a function of glomerular filtration, secretion from the peritubular capillaries to the nephron, and reabsorption from the nephron back to the peritubular capillaries. Clearance is constant in first-order kinetics because a constant fraction of the drug is eliminated per unit time, but it is variable in zero-order kinetics, because a constant amount of drug is eliminated per unit time.
Other articles related to "clearance":
... Renal clearancecan be measured with a timed collection of urine and an analysis of its composition with the aid of the following equation (which follows directly from the ... Inulin clearanceis also used to estimate glomerular filtration rate ...