Influence of piperacillin on pharmacokinetics of etimicin in healthy volunteers

AIM: To investigate the influence of piperacillin on the pharmacokinetics of etimicin. METHODS: Ten healthy male volunteers subjects were administered randomly with 200 mg of etimicin alone or in combination with 2000 mg of piperacillin. After two weeks washout period, the subjects were crossed over to the second regimen. Blood and urinary samples were collected at specified time intervals. Etimicin concentration was analyzed using microbioassay method with Bacillus pumillus as the tested strain. Pharmacokinetic Parameters were determined from serum concentration time data with the 3p87-software package. RESULTS: Maximum serum concentrations of etimicin alone was (21 +/- 5) mg/L compared with (19 +/- 4) mg/L for the combination. The elimination half-lives were (1.9 +/- 0.4) h and (1.9 +/- 0.2) h for etimicin alone and in combination, respectively. The area under the concentration-time curve of etimicin alone was (38 +/- 7) mg(.)h(.)L(-1) as opposed to (41 +/- 8) mg(.)h(.)L(-1) in combination. Twelve hours after administration, urinary recovery rates of etimicin were (56 +/- 8) % and (56 +/- 6) % for etimicin alone and with piperacillin, respectively. CONCLUTION: The results indicated that the pharmacokinetics of etimicin was not affected by concurrent administration of piperacillin in healthy male volunteers. No modification in dosing regimen is necessary when two drugs were co-administered.