Combined use of quinolones with other antibiotics in treatment of experimental plague infection

: The efficacy of combinations of fluoroquinolones (ciprofloxacin and pefloxacin) with betalactams (ampicillin, azlocillin and cefotaxime), aminoglycosides (amikacin) and rifampicin was studied on albino mice infected subcutaneously with plague. The drugs were used in deliberately ineffective or insufficiently effective doses. Synergism was observes with the use of ciprofloxacin and pefloxacin in combinations with amikacin, cefotaxime or rifampicin. The combinations of ciprofloxacin with ampicillin or azlocillin had no synergistic action though the therapeutic effect was not lower. With using the specifically determined doses the efficacy of the combinations could be increased by comparison with that of the drugs used alone.