[Monitoring renal function in patients treated with cytostatics].
BACKGROUND
Some cytostatics, used in the treatment of cancer, are excreted by the kidneys and may be nephrotoxic. The glomerular filtration rate (GFR) represents a method for reliable assessement of the 51Cr-EDTA plasma clearance before and during treatment with nephrotoxic drugs. The aim of this retrospective study was to evaluate whether this method could be replaced by a more simplified GFR estimate calculated from the creatinine plasma concentration.


METHODS
We included all patients who had had at least four GFR measurements in 2005 as part of their nephrotoxic cytostatic treatment. The estimated GFR (eGFR) was calculated from sex, age and weight, according to the Cockcroft formula.


RESULTS
Forty-eight patients with a mean age of 47 years were included. 51Cr-EDTA plasma clearance and eGFR showed a poor correlation (r(2) = 0,678). On average, GFR decreased from 95 ml/min to 80 ml/min from the first to the fourth measurement, whereas plasma concentration of creatinine and eGFR remained unchanged. In 13 patients (27%), the treatment dose was reduced due to a fall in GFR. Seven of these 13 patients would have continued their treatment unchanged, if the clinical decision had been based on eGFR.


CONCLUSIONS
Neither creatinine plasma concentration nor estimated GFR ad modum Cockcroft can be recommended for measurement of GFR in patients treated with nephrotoxic cytostatics.
Hartlev
Louise Brøndt
LB
Klinisk Fysiologi og Nuklearmedicin, Arhus Universitetshospital, Arhus Sygehus, DK-8000 Arhus C. l_broendt@hotmail.com
Rotbøl
Charlotte Bøje
CB
Bluhme
Henrik
H
Palshof
Torben
T
Rehling
Michael
M
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000378:metabolism; D002860:Chromium Radioisotopes / Q000493:pharmacokinetics; D003404:Creatinine / Q000097:blood; D004492:Edetic Acid / Q000493:pharmacokinetics; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy*; D012189:Retrospective Studies
D000970:Antineoplastic Agents; D002860:Chromium Radioisotopes; D004492:Edetic Acid; D003404:Creatinine