Effect of caspofungin on the pharmacokinetics of rifampin (study B)a

Rifampin PK parameterGeometric mean onb:Geometric mean ratio (90% CI)
Day 14Day 15Day 28(1st day of coadministration/control)(14th day of coadministration/control)
AUC0-24 (μg · h/ml)35.2533.4437.750.95 (0.80-1.13)1.07 (0.83-1.38)
Cmax (μg/ml)8.868.358.670.94 (0.79-1.13)0.98 (0.78-1.23)
Tmax (h)c2. (−1.5-2.5)0.00 (−2.0-2.0)
  • a Data are from study B, panel 2 (n = 14). Caspofungin (50 mg) was administered IV once daily, and rifampin (600 mg) was administered orally once daily. PK, pharmacokinetics.

  • b Day 14 data are for controls who received rifampin alone. Day 15 was the first day the drugs were coadministered, and day 28 was the 14th day the drugs were coadministered.

  • c For Tmax, the “geometric means” are median values and the “mean ratios” are median differences (coadministration versus control), with 95% CI provided.