Population pharmacokinetics and limited sampling strategy for therapeutic drug monitoring of mycophenolate mofetil in Japanese patients with lupus nephritis

Table 2 Parameter estimates and bootstrap results of the final model

Parameter	Final model		1000 Bootstrap Results
Parameter	Estimate	RSE (%)	Estimate	95% LLCI	95% ULCI
Population mean
V₁ (L)	22.95	17.71	21.99	13.43	32.75
CL (L/h)	13.15	7.87	12.88	9.49	15.12
Ka (h⁻¹)	2.98	8.90	2.96	2.23	3.87
V₂ (L)	336.03	26.11	350.24	162.42	668.78
Q (L/h)	26.44	7.90	26.56	22.07	30.97
MTT (h)	0.45	12.32	0.46	0.34	0.60
Effect CLcr on CL	0.78	20.22	0.81	0.46	1.28
Effect Alb on CL	-0.88	16.10	-0.92	-1.34	-0.51
Interindividual variability
IIV V₁ (CV%)	86.96	28.18	87.80	22.85	152.75
IIV CL (CV%)	32.23	25.61	32.06	23.70	40.42
IIV MTT (CV%)	58.50	33.37	57.13	31.81	82.45
Residual variability
Proportional error (CV%)	34.09	6.92	33.86	29.86	38.55

RSE relative standard error, 95% LLCI lower limit of the 95% confidence interval, 95% ULCI upper limit of the 95% confidence interval, V₁ central volume of distribution, CL central compartment clearance, Ka absorption rate constant, V₂ peripheral volume of distribution, Q inter-compartmental clearance, MTT mean transit time, CLcr creatinine clearance, Alb serum albumin, IIV interindividual variability
CL (L/h) = 13.15 × (\(\frac{\mathrm{CLcr}}{{\mathrm{CLcr}}_{\mathrm{median}}}\))^0.78 × (\(\frac{\mathrm{Alb}}{{\mathrm{Alb}}_{\mathrm{median}}}\))^−0.88 × exp(ηCL)
CLcr_median was 6.2 L/h, Alb_median was 3.6 g/dL
V1 (L) = 22.95 × exp(ηV)

ISSN: 2055-0294