Lack of interaction between levofloxacin and oxycodone: pharmacokinetics and drug disposition

Previous studies have demonstrated a significant reduction in the oral bioavailability of trovafloxacin and ciprofloxacin when administered concomitantly with an intravenous opiate such as morphine. This decrease in absorption results in a 36% and 50% lower AUC for trovafloxacin and ciprofloxacin, respectively, which could cause clinical failures. The authors investigated the possibility of a similar interaction between oxycodone and levofloxacin. Eight healthy volunteers were randomized in an open-label, two-way crossover study to receive oxycodone, 5 mg p.o. Q4H, and levofloxacin, 500 mg p.o. 1 hour after starting the oxycodone or levofloxacin 500 mg p.o. alone. Blood samples were drawn at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 18, and 24 hours for Cmax, tmax, and AUC determinations. There was not a significant difference (p > 0.05) in AUC (48.59 +/- 8.52 vs. 49.9 +/- 9.93), Cmax (7.73 +/- 2.6 vs. 6.6 +/- 2.0), and tmax (1.1 +/- 0.6 vs. 1.6 +/- 1.1) for levofloxacin versus levofloxacin/oxycodone regimens. It was concluded that oral oxycodone and levofloxacin can be administered concomitantly without a significant decrease in AUC, Cmax, or tmax.