In vitro antimicrobial interactions of arthemeter with some 4-quinolones

Bacterial infections often co-exist with acute malarial attacks. The effect of combining arthemeter (a new antimalarial) with some commonly used 4-quinolones (ciprofloxacin, pefloxacin, norfloxacin and nalidixic acid) was investigated in-vitro with a view to providing data for the design of drug regimens for the treatment of such infections. While arthemeter demonstrated no antibacterial activity whatsoever against any of the test microorganisms (E. coli and Staph. aereus), the 4-quinolones shared marked activity. Comparative analyses of the activity of each quinolone alone and in combination with arthemeter showed 0% 43.8%, 44.9% and -12.2% change in the minimum inhibitory concentration (MIC) of nalidixic acid pefloxacin, ciprofloxacin and norfloxacin respectively against E. coli and -17.5%, 22.3% 35.8% and 50.9% change in the MICs of the same respective drugs against Staph. aureus. These changes in MIC were statistically significant (Pf0.05). With respect to infections caused by E. coli and E. coli, the combination of artemether with ciprofloxacin or pefloxacin proves to be a rational chemotherapeutic regimen when such infection co-exist with malaria.