TABLE 3.

Steady-state pharmacokinetics of pyrazinamide and ethambutola

ParameterValue at rifampin dose (mg):600-mg/450-mg ratio (geometric mean + 95% CIb)P value
600 (n = 23)450 (n = 24)
Pyrazinamide
    AUC0-24 (mg·h/liter)514.5 (266.4-775.3)472.8 (258.9-705.1)1.04 (0.93-1.27)0.269c
    Cmax (mg/liter)46.0 (23.3-71.8)43.8 (19.2-62.1)1.05 (0.91-1.21)0.493c
    Tmax (h) [median (range)]2.5 (2-6)2.75 (1-6)0.897d
    t1/2 (h)6.9 (4.1-11.7)6.6 (3.9-12.7)1.04 (0.89-1.22)0.593c
Ethambutol
    AUC0-24 (mg·h/liter)14.7 (10.0-23.4)14.4 (9.6-22.5)1.02 (0.88-1.17)0.830c
    Cmax (mg/liter)2.3 (1.2-5.6)2.4 (1.1-4.9)0.98 (0.77-1.24)0.863c
    Tmax (h) [median (range)]2.5 (1.5-4)2.5 (1.5-6)0.397d
    t1/2 (h)4.6 (1.8-6.8)4.2 (2.6-5.5)1.09 (0.95-1.24)0.217c
  • a After daily administration of 1,500 mg (30 mg/kg) and 750 mg (15 mg/kg) (geometric mean plus range, unless stated otherwise).

  • b CI, confidence interval.

  • c Independent t test on log-transformed data.

  • d Wilcoxon rank sum test.