Effects of isolation housing and timing of drug administration on amikacin kinetics in mice.

To study the influences of social condition and drug administration time on amikacin metabolism in mice. Forty Male ICR mice were randomly assigned into 4 groups according to 1) housing condition: individual housing (I, one mouse in a cage) or aggregated housing (A, 10 mice in a cage) and 2) drug administration time: at midday (D) or at midnight (N), i.e. I-D, I-N, A-D, and A-N groups. Amikacin was injected s.c. 15 mg.kg-1 after 4 wk of raising at D or N. Blood samples were taken at 5, 10, 15, 20, 30, and 60 min after medication in each mouse. Plasma amikacin was measured by enzyme immunoassay. The concentration-time data were fitted with one-compartment open model in each mouse and data were analyzed with group t test. The clearance (Cl) of amikacin was larger and the half-life (T1/2) was shorter in A-N group than in A-D or I-N groups respectively. AUC(0-1) in A-N group was less than in I-N group. No differences of kinetic parameters between 2 isolated housing (I-D and I-N) groups were found. Aggregated housing and midnight drug administration increased the disposition of amikacin.