Dosing and Body Weights

$$ \text{CrCl} = \frac{(140-\text{age})\text{IBW}}{72*\text{SCr}}*0.85; (\text{if female}) $$

$$ \text{IBW}_\text{M} = 50;(kg)+2.3(Ht; (in)-60;(in)) $$

$$ \text{IBW}_\text{F} = 45.5;(kg)+2.3(Ht; (in)-60;(in)) $$

$$ \text{NBW} = \text{IBW} + 0.25(Wt-\text{IBW}) $$

$$ \text{AdjBW} = \text{IBW} + 0.4(Wt-\text{IBW}) $$

$$ \text{BSA} (m^2) = \sqrt \frac{\text{mass} (kg) * \text{height} (cm)}{3600} $$

$$ \text{LBW}_\text{M} = \frac{9270 \times \text{Wt}}{216 \times \text{BMI} + 6680} $$

$$ \text{LBW}_\text{F} = \frac{9270 \times \text{Wt}}{244 \times \text{BMI} + 8780} $$

For CrCL, use Wt if Wt < IBW, LBW if BMI ≥ 40, IBW or AdjBW otherwise

General PK

$$ C_{ss} = \frac{F(D/\tau)}{CL} \text{ (intermittent)} $$

$$ C_{ss} = \frac{\text{Rate}}{CL} \text{ (infusions)} $$

$$ E = \frac{f_\text{unbound}CL_\text{int}}{Q+f_\text{unbound}CL_\text{int}} $$

$$ CL = Q \times E $$

$$ CL = k \times V_d $$

$$ V_d = V_\text{blood} + \frac{f_b}{f_t}V_\text{tissue} $$

$$ F = \frac{\text{AUC}\text{PO}}{\text{Dose}\text{PO}} \div \frac{\text{AUC}\text{IV}}{\text{Dose}\text{IV}} = \frac{D_\text{IV}\text{AUC}\text{PO}}{D\text{PO}\text{AUC}_\text{IV}} $$

1-Compartment Model

$$ \tau_\text{est} = \frac{\ln{(C_\text{max}} / C_\text{min})}{k} + t_\text{inf} $$

$$ MD_\text{est} = \frac{C_\text{max} t_\text{inf} V k \left( 1 - e^{-k\tau} \right)}{\left( 1 - e^{-kt_\text{inf}} \right)} $$

$$ V = \frac{MD \left( 1 - e^{-kt_\text{inf}} \right)}{t_\text{inf}k\left( C_\text{max} - C_\text{min}e^{-kt_\text{inf}} \right)} $$

$$ C_\text{max} = \frac{MD \left( 1 - e^{-kt_\text{inf}} \right)}{t_\text{inf} V k \left( 1 - e^{-k\tau} \right)} $$

$$ C_\text{pk} = C_\text{max} e^{-k(t_\text{pk} - t_\text{max})} $$

$$ C_\text{min} = C_\text{max} e^{-k(\tau - t_\text{inf})} $$

$$ C_\text{min} = C_\text{tr} e^{-k(t_\text{min} - t_\text{tr})} $$

$$ C[b] = C[a] e^{-k (a - b)} $$