TABLE 1.
Estimates of population pharmacokinetic parameters of clarithromycin and 14(R)-hydroxy-clarithromycin
| Parameter (abbreviation, units) | Point estimate | 95% confidence interval | % Relative standard error of estimated variance |
|---|---|---|---|
| Weibull absorption rate constant (kw, h−1) | 0.56 | 0.42-0.69 | |
| Weibull shape parameter (λ) | 2.23 | 1.67-2.77 | |
| Apparent vol of distribution of clarithromycin (Vp, liters) | 172 | 145-198 | |
| Apparent total clearance of clarithromycin (CLp, liters/h) | 60 | 40-80 | |
| Noninhibited fraction of clarithromycin clearance (FCLp) | 0.10 | 0.02-0.17 | |
| Transfer rate constant into and from inhibition compartment (ki, h−1) | 2.01 | 0.09-3.93 | |
| Concn in inhibition compartment yielding 50% inhibition of maximum clearance (IC50, μg/ml) | 0.77 | 0.23-1.28 | |
| Apparent total clearance of 14-OH-clarithromycin (CLmet, liters/h) | 50.2 | 42.3-58.1 | |
| Apparent vol of distribution of 14-OH-clarithromycin (Vmet, liters) | 34 | 12-56 | |
| Between-subject variability (%) in: | |||
| kw | 45.3 | 7.93 | |
| Vp | 25.3 | 2.83 | |
| CLp | 17.4 | 1.15 | |
| CLmet | 27.9 | 2.11 | |
| Residual variability | |||
| Additive error of clarithromycin (μg/ml) | 0.12 | 2.40 | |
| Additive error of 14-OH-clarithromycin (μg/ml) | 0.01 | 0.18 |