Evaluation of Once Daily Aminoglycoside Use in the Elderly

Abstract

Purpose

This study evaluated the incidence of nephrotoxicity due to once daily aminoglycoside (ODA) use in elderly patients at two South Florida institutions.

Methods

A retrospective review of all patients who received 7 mg/kg/day of either gentamicin or tobramycin was conducted.

Results

Eighty-one (49%) males and 84 (51%) females with a mean age of 73 (range, 60 to 95) years were included. Nephrotoxicity was evident in 16 patients (9.7%). Of these, eight (4.8%) experienced nephrotoxicity possibly associated with aminoglycoside administration. A subgroup analysis of nonnephrotoxic patients compared with nephrotoxic patients revealed no significant differences in mean initial serum creatinine (1 mg/dL vs 0.95 mg/dL, P = 0.861) or dosing interval (31.4 vs 31.5 hours, P = 0.983). The mean duration of aminoglycoside treatment was less in the nonnephrotoxic group compared with the nephrotoxic group (5.2 vs 9.9 days, P < 0.05).

Conclusion

The results of this retrospective evaluation suggest that ODA dosing in the elderly is safe; however, patients should be monitored closely, especially when they require more than 5 days of aminoglycoside therapy, or are receiving concomitant nephrotoxic agents.