Template:DoseConcentrationClearance

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Pharmacokinetic metrics

Characteristic Description Symbol Unit Formula Worked example
value
Dose Amount of drug administered. <math>D</math> <math>\mathrm{mol}</math> Design parameter 500 mmol
Dosing interval Time between drug dose administrations. <math>\tau</math> <math>\mathrm{s}</math> Design parameter 24 h
Cmax The peak plasma concentration of a drug after administration. <math>C_\text{max}</math> <math>\mathrm{M}</math> Direct measurement 60.9 mmol/L
tmax Time to reach Cmax. <math>t_\text{max}</math> <math>\mathrm{s}</math> Direct measurement 3.9 h
Cmin The lowest (trough) concentration that a drug reaches before the next dose is administered. <math>C_{\text{min}, \text{ss}}</math> <math>\mathrm{M}</math> Direct measurement 27.7 mmol/L
Volume of distribution The apparent volume in which a drug is distributed (i.e., the parameter relating drug concentration in plasma to drug amount in the body). <math>V_\text{d}</math> <math>\mathrm{m}^3</math> <math>\frac{D}{C_0}</math> 6.0 L
Concentration Amount of drug in a given volume of plasma. <math>C_{0}, C_\text{ss}</math> <math>\mathrm{M}</math> <math>\frac{D}{V_\text{d}}</math> 83.3 mmol/L
Absorption half-life The time required for the concentration of the drug to double its original value for oral and other extravascular routes.[citation needed] <math>t_{\frac{1}{2}a}</math> <math>\mathrm{s}</math> <math>\frac{\ln(2)}{k_\text{a}}</math> 1.0 h
Absorption rate constant The rate at which a drug enters into the body for oral and other extravascular routes. <math>k_\text{a}</math> <math>\mathrm{s}^{-1}</math> <math>\frac{\ln(2)}{t_{\frac{1}{2}a}}</math> 0.693 −1
[[Biological half-life|Elimination half-Template:Zero width joinerlife]] The time required for the concentration of the drug to reach half of its original value. <math>t_{\frac{1}{2}b}</math> <math>\mathrm{s}</math> <math>\frac{\ln(2)}{k_\text{e}}</math> 12 h
Elimination rate constant The rate at which a drug is removed from the body. <math>k_\text{e}</math> <math>\mathrm{s}^{-1}</math> <math>\frac{\ln(2)}{t_{\frac{1}{2}b}} = \frac{CL}{V_\text{d}}</math> 0.0578 h−1
Infusion rate Rate of infusion required to balance elimination. <math>k_\text{in}</math> <math>\mathrm{mol/s}</math> <math>C_\text{ss} \cdot CL</math> 50 mmol/h
Area under the curve The integral of the concentration-time curve (after a single dose or in steady state). <math>AUC_{0 - \infty}</math> <math>\mathrm{M}\cdot\mathrm{s}</math> <math>\int_{0}^{\infty}C\, \operatorname{d}t</math> 1,320 mmol/L·h
<math>AUC_{\tau, \text{ss}}</math> <math>\mathrm{M}\cdot\mathrm{s}</math> <math>\int_{t}^{t + \tau}C\, \operatorname{d}t</math>
Clearance The volume of plasma cleared of the drug per unit time. <math>CL</math> <math>\mathrm{m}^3/\mathrm{s}</math> <math>V_\text{d} \cdot k_\text{e} = \frac{D}{AUC}</math> 0.38 L/h
Bioavailability The systemically available fraction of a drug. <math>f</math> Unitless <math>\frac{AUC_\text{po} \cdot D_\text{iv}}{AUC_\text{iv} \cdot D_\text{po}}</math> 0.8
Fluctuation Peak trough fluctuation within one dosing interval at steady state. <math>\%PTF</math> <math>\%</math> <math>\frac{C_{\text{max}, \text{ss}} - C_{\text{min}, \text{ss}}}{C_{\text{av}, \text{ss}}} \cdot 100\%</math>
where
<math>C_{\text{av},\text{ss}} = \frac{1}{\tau}AUC_{\tau, \text{ss}}</math>
41.8%
Template documentation

See also

References