Risk factors for nephrotoxicity in elderly patients receiving once-daily aminoglycosides.
BACKGROUND
There remain concerns about the safety of once-daily dosing of aminoglycosides (AGs) in the elderly.


OBJECTIVE
To assess the safety of once-daily AGs in elderly patients and evaluate possible risk factors for nephrotoxicity.


METHODS
Prospective, non-interventional surveillance study.


METHODS
All patients receiving AGs were monitored over 4 months. Clinicians determined the AG dose for each patient after estimating patient weight and calculating creatinine clearance (CrCl) using the Cockcroft-Gault formula. Parallel figures were calculated by the investigators using measured weight. Clinicians obtained an AG trough level 24 h after initiation of treatment, and, if non-toxic, every 5-7 days thereafter. AG toxicity was defined as an increase in serum creatinine of > or =50%.


RESULTS
In the study period, 249 consecutive patients received an AG: 116 (47%) males, mean+/-SD age 75+/-16 years. Forty-two (17%) received amikacin and 207 (83%) gentamicin. An increase of > or =50% in serum creatinine was detected in 31/249 (12.4%); maximal creatinine was < or =177 micromol/l in 16/249 (6.4%), 186-265 micromol/l in nine (3.6%), and >265 micromol/l in six (2.4%). None developed oliguric renal failure. Renal damage correlated with a high AG trough level (>1.1 microg/ml) (p<0.001); haemoglobin level <10 g/dl (p<0.05); hospital admission >7 days prior to AG treatment (p<0.005); and AG treatment > or =11 days (p<0.05). Mean CrCl based on estimated weight was 52+/-18 ml/min; that based on actual weight was 71+/-37 ml/min. Despite this, mean AG dose was 1.3+/-0.6 higher than optimal.


CONCLUSIONS
Oliguric and/or lasting renal toxicity is rare in elderly patients receiving once-daily aminoglycosides for <11 days, if regular trough drug levels are monitored.
Raveh
D
D
Infectious Diseases Unit, Department of Geriatrics, Shaare Zedek Medical Center, Jerusalem, Israel.
Kopyt
M
M
Hite
Y
Y
Rudensky
B
B
Sonnenblick
M
M
Yinnon
A M
AM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000583:Amikacin / Q000009:adverse effects / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001424:Bacterial Infections / Q000188:drug therapy; D003404:Creatinine / Q000097:blood; D004334:Drug Administration Schedule; D005260:Female; D005839:Gentamicins / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D007674:Kidney Diseases / Q000097:blood / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
D000900:Anti-Bacterial Agents; D005839:Gentamicins; D000583:Amikacin; D003404:Creatinine