min/kg) Half-life
(Hours) Cmax
(µg/mL) Vdss
(L/kg)
9 Months–
13 years Single-Oral
2 mg/kg 0.40 (38%)
N=14 25.0 2.9 (22%)
N=16 —
9 Months–
13 years Single-Oral
8 mg/kg 0.51 (60%)
N=15 19.5 9.8 (20%)
N=15 —
5–15 years Multiple IV
2 mg/kg 0.49 (40%)
N=4 17.4 5.5 (25%)
N=5 0.722 (36%)
N=4
5–15 years Multiple IV
4 mg/kg 0.59 (64%)
N=5 15.2 11.4 (44%)
N=6 0.729 (33%)
N=5
5–15 years Multiple IV
8 mg/kg 0.66 (31%)
N=7 17.6 14.1 (22%)
N=8 1.069 (37%)
N=7
Clearance corrected for body weight was not affected by age in these studies. Mean body clearance in adults is reported to be 0.23 (17%) mL/min/kg.
In premature newborns (gestational age 26 to 29 weeks), the mean (%cv) clearance within 36 hours of birth was 0.180 (35%, N=7) mL/min/kg, which increased with time to a mean of 0.218 (31%, N=9) mL/min/kg six days later and 0.333 (56%, N=4) mL/min/kg 12 days later. Similarly, the half-life was 73.6 hours, which decreased with time to a mean of 53.2 hours six days later and 46.6 hours 12 days later.
Pharmacokinetics in Elderly
A pharmacokinetic study was conducted in 22 subjects, 65 years of age or older receiving a single 50 mg oral dose of fluconazole. Ten of these patients were concomitantly receiving diuretics. The Cmax was 1.54 mcg/mL and occurred at 1.3 hours post dose. The mean AUC was 76.4 ± 20.3 mcg∙h/mL, and the mean terminal half-life was 46.2 hours. These pharmacokinetic parameter values are higher than analogous values reported for normal young male volunteers. Coadministration of diuretics did not significantly alter AUC or Cmax. In addition, creatinine clearance (74 mL/min), the percent of drug recovered unchanged in urine (0–24 hr, 22%), and the fluconazole renal clearance estimates (0.124 mL/min/kg) for the elderly were generally lower than those of younger volunteers. Thus, the alteration of fluconazole disposition in the elderly appears to be related to reduced renal function characteristic of this group. A plot of each subject's terminal elimination half-life versus creatinine clearance compared with the predicted half-life – creatinine clearance curve derived from normal subjects and subjects with varying degrees of renal insufficiency indicated that 21 of 22 subjects fell within the 95% confidence limit of the predicted half-life – creatinine clearance curves. These results are consistent with the hypothesis that higher values for the pharmacokinetic parameters observed in the elderly subjects compared with normal young male volunteers are due to the decreased kidney function that is expected in the elderly.
Drug Interaction Studies
Oral contraceptives
Oral contraceptives were administered as a single dose both before and after the oral administration of DIFLUCAN 50 mg once daily for 10 days in 10 healthy women. There was no significant difference in ethinyl estradiol or levonorgestrel AUC after the administration of 50 mg of DIFLUCAN. The mean increase in ethinyl estradiol AUC was 6% (range: –47 to 108%) and levonorgestrel AUC increased 17% (range: –33 to 141%).
In a second study, twenty-five normal females received daily doses of both 200 mg DIFLUCAN tablets or placebo for two, ten-day periods. The treatment cycles were