Abstract:
The objective of this study was to observe the drug interaction between levofloxacin and omeprazole using
urinary excretion data. Levofloxacin tablet and omeprazole capsule were administered separately as well as in
combination in fasting condition with a wash out period of two weeks after each administration. Urine was
collected at different time intervals of 0, 0-2, 2-4, 4-8, 8-12, 12-24, 24-36 and 36-48 hr post-dose and analyzed
using a validated HPLC with UV detection. Different pharmacokinetic parameters for both drugs were
determined using non-compartmental method. The maximum rate of excretion (Rmax) of levofloxacin was not
decreased significantly when co-administered with omeprazole (p>0.05). Similarly no significant difference (p
= 0.350) was observed for Rmax of omeprazole when co-administered with levofloxacin. Again the fraction of
levofloxacin excreted (fe/f) was not changed significantly (p = 0.953) due to the co-administration of
omeprazole. Similarly fraction of omeprazole excreted (fe/f) also remained unaffected (p = 0.672) when coadministered with levofloxacin. No significant change was observed for the area under the rate of excretion
versus midpoint of time interval curve from zero to 48 hours (AURC0-48) for levofloxacin and omeprazole (p =
0.816 and 0.792 respectively) when administered separately and co-administered with each other. The study
clearly revealed that levofloxacin and omeprazole do not undergo any kind of interactions when administered
together. So it can be concluded that these two drugs can be prescribed together to achieve optimum therapeutic activity.
