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VOL. 75 (2), 217-231, 2009 (CU)II IN VIVO INTERACTION WITH CEFOTAXIME

that have been analysed. So, the presence of copper is an influential
factor in the concentration of free cefotaxime.

This observation has been supported with the help of a statistical
analysis, here the means of concentrations of free cefotaxime, in
blood, liver, spleen, lung, heart and kidney of rats without copper and
of the rats with it, at 30, 60, 90, 120, 150, 180 and 210 min. after
administration of this cephalosporin, have been compared. This
comparison has been done by means of a T distribution with p < 0.05.

Therefore, in all those times is dismissed the nule hypothesis
and the averages differences of cefotaxime concentrations were
statistically significant. As deduced from these differences between
the free cefotaxime concentration in rats with and without copper
did not happen randomly, so those differences in the concentration
could be due to the formation of antibiotic/metal complex, remaining
a lesser concentration of free cefotaxime.

3.2. Distribution of cefotaxime

Tables 1 and 2 show the greatest concentration of cefotaxime in
blood. In the assayed organs the concentration of this cephalosporin
is decreasing in the sense: Kidney > liver > lung > spleen > heart.
Therefore cefotaxime is mainly stored in kidney. This fact happened
in both groups, so we induced, the metal is not an influential factor
in the distribution of cefotaxime.

Table 1. Average concentrations (mg/mL) of free cefotaxime in rats
without copper

TIME (MIN)

SAMPLES 30 60 90 120 150 180 210

BLOOD 0.80 0.46 0.25 0.14 0.08 0.06 0.02
LIVER 6.03.10–5 2.68.10–5 2.16.10–5 1.71.10–5 1.42.10–5 1.37.10–5 1.24.10–5
SPLEEN 2.70.10–5 1.58.10–5 1.45.10–5 0.53.10–5 0.41.10–5 0.39.10–5 0.38.10–5
KIDNEY 24.2.10–5 18.1.10–5 10.6.10–5 5.90.10–5 5.01.10–5 4.81.10–5 3.17.10–5
LUNG 7.19.10–5 5.26.10–5 3.52.10–5 3.02.10–5 1.33.10–5 1.22.10–5 0.46.10–5
HEART 2.56.10–5 1.87.10–5 1.23.10–5 1.14.10–5 1.08.10–5 0.86.10–5 0.85.10–5

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