Effect of norfloxacin infusion rate on total dose and concentrations of norfloxacin in plasma, brain and CSF at onset of maximum seizure in rats
| Parameter | Infusion Rate2-a (μmol/hr) | |||
|---|---|---|---|---|
| 480 | 960 | 1440 | 1920 | |
| No. of animals | 7 | 8 | 6 | 7 |
| Body weight (g) | 280 ± 14 | 280 ± 8 | 275 ± 14 | 282 ± 11 |
| Infusion time (min) | 69.4 ± 8.9 | 34.5 ± 4.7 | 19.7 ± 2.9 | 12.9 ± 2.3 |
| Total dose (μmol/kg) | 1996 ± 304 | 1966 ± 253 | 1750 ± 275 | 1476 ± 294ab |
| Total plasma concentration (μmol/liter) | 1103 ± 196cd | 1400 ± 2582-d | 1836 ± 335de | 1646 ± 610 |
| Free plasma concentration (μmol/liter) | 862 ± 222de | 1146 ± 169df | 1490 ± 308de | 1277 ± 4372-c |
| CSF concentration (μmol/liter) | 49.2 ± 6.62-c | 48.2 ± 11.92-f | 42.6 ± 7.5 | 50.4 ± 14.72-c |
| Free (unbound) fraction in plasma | 0.82 ± 0.14 | 0.84 ± 0.11 | 0.81 ± 0.07 | 0.81 ± 0.14 |
| CSF/free plasma concentration ratio | 0.063 ± 0.0252-g | 0.042 ± 0.011 | 0.031 ± 0.008 | 0.038 ± 0.008 |
| Brain concentration (μmol/kg) | 87 ± 21 | 113 ± 272-f | 129 ± 132-e | 113 ± 31 |
Results are reported as mean ± SD.
↵2-a Infusion rate had a significant effect (p < .05 by one-way analysis of variance) on infusion time, total dose and concentrations in plasma (total and unbound), but not on CSF and brain concentrations, and unbound fraction in plasma.
2-b Significantly different from corresponding doses at 480 and 960 μmol/hr infusion rates (P < .001 by a Student’st test).
↵2-c n = 6.
↵2-d Significantly different from other infusion rates (P < .05 by a Student’s t test), except for the 1920 μmol/hr infusion rates (Mann-Whitney U test).
↵2-e n = 5.
↵2-f n = 7.
↵2-g Significantly different from corresponding ratio at the 1440 μmol/hr infusion rate (P < .05 by a Student’s ttest).