Objective   To explore the pharmacokinetic differences of levofloxacin by intravenous injection and oral administration in the prostate of rat model of prostatitis.   Methods   A total of 60 rats were inflicted with 0.1 ml 1.8×10

7

cfu/ml E. coli injection in their prostates to establish prostatitis model. On the basis of previous oral administration experiment

these 60 rats with bacterial prostatitis were injected levofloxacin (44 mg/kg)

then the tissue of prostate was collected in 1

3

7.5

15

30

60

120

240

480 and 720 min after administration and made into homogenate. The concentration of levofloxacin was detected by HPLC

and pharmacokinetic parameters were calculated with 3p97 software program. The results were compared with data from previous oral administration.   Results   The concentration curves based on drug-time of intravenous injection was presented by two-compartments model. The main pharmacokinetic parameters were: t

1/2β

2.1±0.7 h

t

max

0.6±0.2 h

C

max

72.3±23.3 μg/g and AUC

0-12

253.7±91.7 μg/（h·g）. Compared with data from previous oral administration

t

1/2β

t

max

C

max

and AUC

0-12

had significant differences among the 2 different ways of administration (P0.01).   Conclusion   Intravenous injection can significantly increase the concentration of levofloxacin in the tissue of prostatitis

while oral administration can significantly prolong its half life in the tissue of prostatitis.