False Elevation in Serum Creatinine Levels
- Deirdre Herrington, MD;
- George L. Drusano, MD;
- Ulysses Smalls;
- Harold C. Standiford, MD
Since this article does not have an abstract, we have provided the first 150 words of the full text.
Excerpt
To the Editor.— Flucytosine causes a falsely elevated serum creatinine measurement when an analytic method using creatinine iminohydrolase is employed.1 This enzymatic assay is being introduced into many hospital laboratories, replacing systems with which flucytosine did not interfere.
A 53-year-old man with alcoholic cirrhosis and cryptococcal meningitis was receiving therapy with amphotericin B (0.3 mg/kg/day) and flucytosine (150 mg/kg/day). His serum creatinine level, which was 1.0 mg/dL prior to drug therapy, rose to 3.2 mg/dL on the fourth day of therapy. The dosing regimen was altered because of the possibility of amphotericin-related renal dysfunction and the consequent possibility of bone marrow toxic reaction from flucytosine. Serum creatinine values then fluctuated on a daily basis, with a high of 6.3 mg/dL, a low of 1.1 mg/dL, and a mean of 3.5 mg/dL. It was discovered that creatinine
measurements were being determined on a Kodak Ektachem 400
