AVMA Journals Style Pharmacologic Pharmacokinetics Terminology
The following list represents the Journals's preferred format for commonly encountered pharmacologic and pharmacokinetics terms.
Term* | Standard expansion† | Additional information | Typical units‡ |
α | Alpha | Rate constant for the distribution portion of the plasma concentration-versus-time curve, as in: C(t) = A•e^{–α•t} + B•e^{–β•t} | h^{–1} |
β | Beta | Rate constant for the elimination portion of the plasma concentration-versus-time curve, as in: C(t) = A•e^{–α•t} + B•e^{–β•t} | h^{–1} |
λ_{z} | Terminal rate constant | Also: terminal slope of the concentration- versus-time curve | h^{–1} |
AUC | Area under the concentration- versus-time curve | μg•h/mL | |
AUC_{0–last} | Area under the concentration- versus-time curve from time 0 to the last measured concentration | μg•h/mL | |
AUC_{0–∞} | Area under the concentration-versus-time curve from time 0 to infinity | μg•h/mL | |
AUMC | Area under the first moment curve | μg•h^{2}/mL | |
Cl | Clearance | Also: systemic clearance | mL/kg/h |
Cl/F | Clearance corrected for bioavailability | Used for a non-IV dose (also: clearance per fraction absorbed) | mL/kg/h |
C | Concentration | μg/mL | |
C_{0} | Concentration at time 0 | Used for an IV dose | μg/mL |
C_{max} | Maximum observed concentration | Also: maximum serum concentration, maximum plasma concentration, or peak concentration | μg/mL |
C_{min} | Minimum observed concentration | Also: minimum serum concentration or minimum plasma concentration | μg/mL |
C_{ss} | Concentration at steady state | Also: plasma concentration at steady state or serum concentration at steady state | μg/mL |
F | Bioavailability | Also: extent of absorption or fraction of the dose absorbed | No units (expressed as a fraction) or % (F X 100) |
k | Rate constant | h^{–1} | |
k_{01} | Rate constant for absorption into the central compartment | Used for a non-IV dose | h^{–1} |
k_{10} | Rate constant for drug elimination from the central compartment | h^{–1} | |
k_{12} | Rate constant for drug movement from the central to the peripheral compartment | Also: rate constant for drug movement from compartment 1 to compartment 2 | h^{–1} |
k_{21} | Rate constant for drug movement from the peripheral to the central compartment | Also: rate constant for drug movement from compartment 2 to compartment 1 | h^{–1} |
k_{e} or k_{el} | Elimination rate constant | h^{–1} | |
k_{a} or k_{abs} | Absorption rate constant | Used for a non-IV dose | h^{–1} |
MIC | Minimum inhibitory concentration | μg/mL | |
MIC_{50} | Minimum inhibitory concentration for 50% of isolates | μg/mL | |
MIC_{90} | Minimum inhibitory concentration for 90% of isolates | μg/mL | |
MRT | Mean residence time | min | |
t_{1/2} | Half-life | Also: apparent elimination half-life | min |
t_{1/2α} | Distribution half-life | Corresponds to ln2/α | min |
t_{1/2β} | Elimination half-life | Corresponds to ln2/β | min |
t_{1/2λ} | Terminal half-life | Corresponds to ln2/λ | min |
t_{1/2} k_{el} | Half-life for drug elimination | Also: t_{1/2} k_{e} | min |
t_{1/2} k_{a} | Half-life for drug absorption | Used for a non-IV dose (Also: t_{1/2} k_{abs}) | min |
t_{lag} | Time delay between drug administration and first observed concentration |
Also: lag time | min |
t_{max} | Time to maximum concentration | min | |
Vd_{C} | Volume of distribution of the central compartment | Used for an IV dose (equivalent to V_{1}) | L/kg |
Vd | Volume of distribution | L/kg | |
Vd_{area} | Volume of distribution calculated using the AUC method | Used for an IV dose (equivalent to V_{Z}) | L/kg |
Vd/F | Volume of distribution corrected for bioavailability | Also: volume of distribution per fraction absorbed | L/kg |
Vd_{ss} | Volume of distribution at steady state | Used for an IV dose | L/kg |
Vd_{ss}/F | Volume of distribution at steady state corrected for bioavailability | Also: volume of distribution at steady state per fraction absorbed | L/kg |
*The MRT can include a subscript to indicate the data used for calculations (eg, MRT_{0–obs}).
†For C and related parameters, the text should indicate the sample type for which concentrations were evaluated (these may not always be measured in serum or plasma). The variable that the rate constant k pertains to should also be mentioned in the text.
‡Units that are equivalent when conversions are applied are also acceptable (eg, L/kg/h or mL/kg/min for Cl or Cl/F; ng/mL or mg/L for C and related parameters; min^{–1} for k and related parameters; h for t and t_{1/2} related parameters; mg/L for MIC data; mL/kg for Vd and related parameters). Units of mL/kg/h are equivalent to mL•h^{–1}•kg^{–1}; the former term is preferred because of its simplicity.