clearance


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clear·ance

(klēr'ants),
1. Removal of a substance from the blood, for example, by renal excretion, expressed in terms of the volume flow of arterial blood or plasma that would contain the amount of substance removed per unit of time; measured in mL/min. Renal clearance of any substance except urea or free water is calculated as the urine flow in mL/min multiplied by the urinary concentration of the substance divided by the arterial plasma concentration of the substance; normal human values are commonly expressed per 1.73 m2 body surface area.
2. A condition in which bodies may pass each other without hindrance, or the distance between bodies.
3. Removal of something from some place; for example, esophageal acid clearance refers to removal from the esophagus of some acid that has refluxed into it from the stomach, evaluated by the time taken for restoration of a normal pH in the esophagus.

clearance

/clear·ance/ (klēr´ans)
1. the act of clearing.
2. a quantitative measure of the rate at which a substance is removed from the blood, as by the kidneys, the liver, or hemodialysis; the volume of plasma cleared per unit time. Symbol C.
3. the space between opposed structures.

blood-urea clearance  urea c.
creatinine clearance  the volume of plasma cleared of creatinine after parenteral administration of a specified amount of the substance.
inulin clearance  an expression of the renal efficiency in eliminating inulin from the blood.
mucociliary clearance  the clearance of mucus and other materials from the airways by the cilia of the epithelial cells.
urea clearance  the volume of the blood cleared of urea per minute by either renal clearance or hemodialysis.

clearance

(klîr′əns)
n.
1. A space cleared; a clearing.
2.
a. The removal by the kidneys of a substance from blood plasma.
b. Renal clearance.

clearance (C)

[klir′əns]
Etymology: L, clarus, clear
the removal of a substance from the blood via the kidneys. Kidney function can be tested by measuring the amount of a specific substance excreted in the urine in a given length of time.
FDAspeak See Marketing clearance
Occupational medicine The amount of space above a worker’s head
Pharmacology A measure of the elimination of a drug, therapeutic agent, or other substance from the body or other biologic system; clearance is expressed as a hypothetical volume that is completely removed in a given unit of time
Pharmacokinetics The product of the volume of distribution and the elimination rate constant; much of a drug’s elimination is via the kidneys and clearance is commonly expressed in mL/min or L/hr
Physiology
(1) The removal of a substance from the blood by metabolism or excretion
(2) A quantitative measure of such a removal
Vox populi The amount of space between 2 closely related substances

clearance

Pharmacology The elimination of a drug, therapeutic agent, or other substance from the body or other biologic system; clearance is expressed as a hypothetical volume that is completely removed in a given unit of time; in terms of pharmacokinetics, clearance is the product of the volume of distribution and the elimination rate constant; much of a drug's elimination is via the kidneys and clearance is commonly expressed in mL/min or L/hr. See Hepatic clearance, Renal clearance, Therapeutic drug monitoring, Total body clearance Physiology
1. The removal of a substance from the blood by metabolism or excretion. See Nasal mucociliary clearance.
2. A quantitative measure of item 1.

clear·ance

(klēr'ăns)
1. Indicated as C with a subscript to show the substance removed: removal of a substance from the blood, e.g., by renal excretion, expressed in terms of the volume flow of arterial blood or plasma that would contain the amount of substance removed per unit time; measured in mL per minute; normal values in humans are commonly expressed per 1.73 m2 body surface area.
2. A condition in which bodies may pass each other without hindrance, or the distance between bodies.
3. Removal of something from some place; e.g., "esophageal acid clearance" refers to removal from the esophagus of acid that has refluxed into it from the stomach, evaluated by the time taken for restoration of a normal pH in the esophagus.

clearance

1. The removal of a substance from the blood, usually by the kidneys.
2. The rate of such removal.

clear·ance

(klēr'ăns)
Removal of something from an area.

clearance

the act of clearing; it is a primary pharmacokinetic parameter which describes irreversible removal of a drug from the body by all processes and is made up of renal clearance and metabolic clearance.

blood-urea clearance
the volume of the blood cleared of urea per minute by renal elimination.
Bromsulphalein clearance
see sulfobromophthalein clearance test.
creatinine clearance
inulin clearance
see inulin clearance.
clearance time
the time required for a drug to be eliminated after administration. Eliminated means to the point where it can no longer be detected. Of most importance in avoiding drug residues in food animals and charges of doping in sports animals.
urea clearance
blood-urea clearance.
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