TABLE 2.

Pharmacokinetic parameters from the final population pharmacokinetic model for piperaquine^a

Parameter	Population estimateb (% RSE)c	95% CIc	IIV/IOV (% CV)b (% RSE)c	95% CIc
F	1 fixed		38.2 (3.90), 42.8 (2.07)	36.0–42.3, 43.5–47.8
MTT (h)	2.13 (1.11)	2.09–2.18	37.5 (9.83), 44.7 (1.20)	36.1–52.8, 46.2–48.7
CL/F (liter/h)	53.1 (2.77)	50.2–56.1
VC/F (liter)	1,730 (8.04)	1,441–1,991	90.5 (19.8)	31.4–165
Q1/F (liter/h)	282 (5.60)	249–310
VP1/F (liter)	3,290 (5.10)	2,949–3,595	23.4 (24.1)	17.2–39.9
Q2/F (liter/h)	82.9 (2.42)	78.9–86.6	27.1 (11.9)	24.0–36.7
VP2/F (liter)	25,100 (1.77)	24,170–25,925	31.8 (1.01)	32.0–33.3
Dose occasion effect on F	0.237 fixed
AGE50 (yr)	0.575 fixed
Hill	5.51 fixed
σ	0.198 (4.13)	0.167–0.232

^aAbbreviations: F, relative bioavailability; MTT, mean transit time; CL/F, apparent oral clearance; V_C/F, apparent central volume of distribution; Q/F, intercompartmental clearance; V_P/F, apparent peripheral volume of distribution; AGE₅₀, the age to reach 50% of the full maturation of the elimination clearance; Hill, the shape function in the maturation equation; σ, residual unexplained error of drug measurements (variance); IIV, interindividual variability; IOV, interoccasion variability.

^bComputed population mean parameter estimates from NONMEM. Parameter estimates are based on the typical individual in the prior population with a body weight of 54 kg. IIV and IOV were implemented as an exponential function and are presented as the coefficient of variation (%CV), calculated as $100\times \sqrt{\text{exp}\left(\text{estimate}\right)\hspace{0.17em}-\hspace{0.17em}1}$.

^cBased on nonparametric bootstrap diagnostics (n = 1,000). Parameter precision is presented as relative standard deviation (%RSE), calculated as $100\times \frac{\text{standard deviation}}{\text{mean value}}$.