Half life: Difference between revisions
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Elimination half-life, written as t<sub>1/2</sub>, is the time needed for the concentration of a substance (usually a drug, [[Metabolite|metabolite]] or [[Hormone|hormone]]) to half in the [[blood plasma|blood plasma]].'''<br> ''' | |||
*The t<sub>1/2</sub> or rate of decay (dC/dt) proportional to [[Concentration|concentration]] is exponential so when trying to measure half-life graphs are usually plotted on a [[semi-logarithmic scale|semi-logarithmic scale]] in order to get a straight line which is easier to manipulate. | |||
*Half-life is important in [[Pharmacokinetics|pharmacokinetics]] and depends on how quickly the substance is [[Drug elimination|eliminated]] ie. the clearance as well as on [[Volume distribution|volume distribution]]. | |||
*The t<sub>1/2</sub> or rate of decay (dC/dt) proportional to [[Concentration|concentration | |||
*Half-life is important in [[Pharmacokinetics|pharmacokinetics | |||
*Half-life is important when determining how frequently drugs should be administered. | *Half-life is important when determining how frequently drugs should be administered. | ||
Latest revision as of 07:13, 14 November 2011
Elimination half-life, written as t1/2, is the time needed for the concentration of a substance (usually a drug, metabolite or hormone) to half in the blood plasma.
- The t1/2 or rate of decay (dC/dt) proportional to concentration is exponential so when trying to measure half-life graphs are usually plotted on a semi-logarithmic scale in order to get a straight line which is easier to manipulate.
- Half-life is important in pharmacokinetics and depends on how quickly the substance is eliminated ie. the clearance as well as on volume distribution.
- Half-life is important when determining how frequently drugs should be administered.