TABLE 2.

Summary of population pharmacokinetic parameter estimates^a

Parameter	Fixed effect (RSE)	IIV (RSE)
CL (liters/h)	4.84 (2.38)	50.4 (11.8)
PMA50	50.2 (3.34)
Hill coefficient	3.52 (14.8)
Power creatinine	−0.692 (5.28)
VC (liters)	39.9 (8.15)	232 (17.2)
Q (liters/h)	3.85 (17.3)
VP (liters)	37.8 (10.2)
RUV	0.243 (4.85)
ηCL-ηVC	0.535 (11.2)

^aCL, elimination clearance; V_C, central compartment distribution volume; Q, intercompartmental clearance; V_P, peripheral compartment distribution volume; PMA₅₀, postnatal age half-maximum organ maturation; power creatinine, exponent on creatinine function; RUV, additive residual variability on log-transformed data; ηCL-ηV_C, correlation between variability on clearance and central compartment distribution volume. Clearance and volume parameters were centralized around a 70-kg patient using 0.632, 0.75, and 1 as power functions for CL, Q, and the distribution volumes (V_C and V_P), respectively. IIV, interindividual variability ($100\hspace{0.17em}\times \sqrt{e^{\mathrm{\eta }}\hspace{0.17em}-\hspace{0.17em}1}$); RSE, relative standard errors derived from 962 (out of 1,000) converged nonparametric bootstraps in NONMEM as 100 × (SD/means).