Correspondence
lID 1991;163 (February)
cies is Candida tropicalis [9]. In vitro testing has previously determined Cando krusei to be resistant to fluconazole, with MICs of ~25 p.g/ml [10]. At present, it is not at all clear how useful fluconazole will be for prophylaxis or treatment of systemic candidiasis [1]. I am concerned that fluconazole may allow for Cand. krusei proliferation similar to that of Clos. difficile in patients who have received antibiotics. Further evaluation of fluconazole in preventive or early treatment of disseminated candidiasis in carefully designed clinical trials is warranted.
References 1. Galgiani IN. Fluconazole, a new antifungal agent. Ann Intern Moo 1990;113:177-9. 2. WashtonH. Review of fluconazole: a new triawle antifungal agent. Diagn Microbiol Infect Dis 1989;12:229S-33S. 3. Hughes WT, Armstrong D, Bodey GP, et al. Guidelines for the use of antimicrobial agents in neutropenic patients with unexplained fever. J Infect Dis 1990;161:381-96.
Artifactual Elevation of the Serum Creatinine in Patients Receiving Flucytosine for Cryptococcal Meningitis To THE EDITOR-Weread the comments of Bennett et al. [1] regarding our report of flucytosine interference with the plasma creatinine assay [2]. We appreciate their attention to our letter but believe our report has been misinterpreted. First, they state that "the authors found only one prior publication on this subject." This is never stated in our report, and we cite three references alluding to this phenomenon. Second, according to Bennett et al. we "deplored the fact that two book chapters" (one of which Dr. Bennett authored) "did not mention this artifact." The word "deplore" appears nowhere in our report, and it is clear from our context that our intent was educational, not accusatory. Third, Bennett et al. believe our report is "misleading" because the manufacturer became aware of this problem 6 years previously. We cited the manufacturer's original publication [3] and clearly stated that newer methodology has been instituted in most centers that overcomes the artifactual creatinine elevation. Fourth, the authors imply that so few laboratories use the older technique that it is not worthy of mention in textbook chapters. However, as stated in our report (Robert Fricker, Eastman Kodak [Roch-
Reprints or correspondence: Dr. Charles A. Kennedy, Infectious Disease Division, Internal Medicine Department, Naval Hospital, San Diego, CA 92134-5000. The Journal of Infectious Diseases 1991;163:421 © 1991 by The University of Chicago. All rights reserved. 0022-1899/91/6302-0042$01.00
4. Katz JA, Wagner ML, Gresik MV, Mahoney DR, Fernbach DJ. Typhlitis: an 18-year experience and postmortem review. Cancer 1990; 65:1041-7. 5. Shaked A, Shinar E, Freund H. Neutropenic typhlitis: a plea for conservatism. Dis Colon Rectum 1983;26:351-2. 6. Edwards JE. Candida species. In: Mandell GL, Douglas RG, Bennett JE, eds. Principles and practice of infectious diseases. New York: Churchill Livingstone, 1990;1943-58. 7. Roberts GD. Laboratory methods in basic mycology. In: Finegold SM, Baron EJ, eds. Bailey and Scott's diagnostic microbiology. St. Louis: C. V. Mosby, 1986;678-774. 8. Komshian SV, Uwaydah AK, Sobel JD, Crane LR. Fungemia caused by Candida species and 'Ibrulopsis glabrata in the hospitalized patient: frequency, characteristics, and evaluation of factors influencing outcome. Rev Infect Dis 1989;11:379-90. 9. Weinstein MP, Reller LB, Murphy JR, Lichtenstein KA. The clinical significance of positive blood cultures: a comprehensive analysis of 500 episodes of bacteremia and fungemia in adults. I. Laboratory and epidemiologic observations. Rev Infect Dis 1983;5:35-53. 10. Galgiani IN. Susceptibility of Candida albicans and other yeasts to fluconazole: relation between in vitro and in vivo studies. Rev Infect Dis 1990;12:S272-5.
ester, NY], personal communication), 10%-15% of hospital laboratories using the EKTACHEM analyzer (Eastman Kodak) continue to use dated methodology. Consequently, our observations remain of import to clinicians practicing in these centers. Last, Bennett et al. cite three additional papers [4-6]. Of note, these studies capitalize on the artifactual creatinine elevation to measure flucytosine levels in serum. It was not our intent to assay flucytosine by this method, rather to describe our experience in withholding critically needed amphotericin therapy because of perceived polyene nephrotoxicity. Judging from the Journal's willingness to publish our report and the number of reprint requests we have received it is doubtful that this phenomenon is as widely recognized as Bennett et al. suggest.
Charles A. Kennedy, Matthew B. Goetz, and Glenn E. Mathisen UCLA San Fernando Valley Program in Infectious Disease, UCLA School of Medicine, Los Angeles, California
References 1. Bennett JE, Kroll MR, Washburn RG. Flucytosine interference in creatinine assay. J Infect Dis 1990;162:571-2. 2. Kennedy CA, Goetz MB, Mathisen GE. Artifactual elevation of the serum creatinine in patients receiving flucytosine for cryptococcal meningitis. J Infect Dis 1989;160:1090-1. 3. Kodak EKTACHEM test methodology. Rochester, NY: Eastman Kodak, 1983. 4. Noble MA, Harper B, Grant AG, Bernstein M. Rapid determination of 5-flucytosine levels in blood. J Clin MicrobioI1984;20:996-7. 5. Washburn RG, Klym DM, Kroll MH, Bennett JE. Rapid enzymatic method for measurement of serum flucytosine levels. J Antimicrob Chemother 1986;17:673-7. 6. Huang CM, Kroll MH, Ruddel M, Washburn RG, Bennett JE. An enzymatic method for 5-flucytosine. Clin Chern 1988;34:59-62.
Downloaded from http://jid.oxfordjournals.org/ at University of Bath Library & Learning Centre on July 14, 2015
Michael A. McIlroy St. John Hospital and Medical Center, Detroit, Michigan
421
lID 1991;163 (February)
cies is Candida tropicalis [9]. In vitro testing has previously determined Cando krusei to be resistant to fluconazole, with MICs of ~25 p.g/ml [10]. At present, it is not at all clear how useful fluconazole will be for prophylaxis or treatment of systemic candidiasis [1]. I am concerned that fluconazole may allow for Cand. krusei proliferation similar to that of Clos. difficile in patients who have received antibiotics. Further evaluation of fluconazole in preventive or early treatment of disseminated candidiasis in carefully designed clinical trials is warranted.
References 1. Galgiani IN. Fluconazole, a new antifungal agent. Ann Intern Moo 1990;113:177-9. 2. WashtonH. Review of fluconazole: a new triawle antifungal agent. Diagn Microbiol Infect Dis 1989;12:229S-33S. 3. Hughes WT, Armstrong D, Bodey GP, et al. Guidelines for the use of antimicrobial agents in neutropenic patients with unexplained fever. J Infect Dis 1990;161:381-96.
Artifactual Elevation of the Serum Creatinine in Patients Receiving Flucytosine for Cryptococcal Meningitis To THE EDITOR-Weread the comments of Bennett et al. [1] regarding our report of flucytosine interference with the plasma creatinine assay [2]. We appreciate their attention to our letter but believe our report has been misinterpreted. First, they state that "the authors found only one prior publication on this subject." This is never stated in our report, and we cite three references alluding to this phenomenon. Second, according to Bennett et al. we "deplored the fact that two book chapters" (one of which Dr. Bennett authored) "did not mention this artifact." The word "deplore" appears nowhere in our report, and it is clear from our context that our intent was educational, not accusatory. Third, Bennett et al. believe our report is "misleading" because the manufacturer became aware of this problem 6 years previously. We cited the manufacturer's original publication [3] and clearly stated that newer methodology has been instituted in most centers that overcomes the artifactual creatinine elevation. Fourth, the authors imply that so few laboratories use the older technique that it is not worthy of mention in textbook chapters. However, as stated in our report (Robert Fricker, Eastman Kodak [Roch-
Reprints or correspondence: Dr. Charles A. Kennedy, Infectious Disease Division, Internal Medicine Department, Naval Hospital, San Diego, CA 92134-5000. The Journal of Infectious Diseases 1991;163:421 © 1991 by The University of Chicago. All rights reserved. 0022-1899/91/6302-0042$01.00
4. Katz JA, Wagner ML, Gresik MV, Mahoney DR, Fernbach DJ. Typhlitis: an 18-year experience and postmortem review. Cancer 1990; 65:1041-7. 5. Shaked A, Shinar E, Freund H. Neutropenic typhlitis: a plea for conservatism. Dis Colon Rectum 1983;26:351-2. 6. Edwards JE. Candida species. In: Mandell GL, Douglas RG, Bennett JE, eds. Principles and practice of infectious diseases. New York: Churchill Livingstone, 1990;1943-58. 7. Roberts GD. Laboratory methods in basic mycology. In: Finegold SM, Baron EJ, eds. Bailey and Scott's diagnostic microbiology. St. Louis: C. V. Mosby, 1986;678-774. 8. Komshian SV, Uwaydah AK, Sobel JD, Crane LR. Fungemia caused by Candida species and 'Ibrulopsis glabrata in the hospitalized patient: frequency, characteristics, and evaluation of factors influencing outcome. Rev Infect Dis 1989;11:379-90. 9. Weinstein MP, Reller LB, Murphy JR, Lichtenstein KA. The clinical significance of positive blood cultures: a comprehensive analysis of 500 episodes of bacteremia and fungemia in adults. I. Laboratory and epidemiologic observations. Rev Infect Dis 1983;5:35-53. 10. Galgiani IN. Susceptibility of Candida albicans and other yeasts to fluconazole: relation between in vitro and in vivo studies. Rev Infect Dis 1990;12:S272-5.
ester, NY], personal communication), 10%-15% of hospital laboratories using the EKTACHEM analyzer (Eastman Kodak) continue to use dated methodology. Consequently, our observations remain of import to clinicians practicing in these centers. Last, Bennett et al. cite three additional papers [4-6]. Of note, these studies capitalize on the artifactual creatinine elevation to measure flucytosine levels in serum. It was not our intent to assay flucytosine by this method, rather to describe our experience in withholding critically needed amphotericin therapy because of perceived polyene nephrotoxicity. Judging from the Journal's willingness to publish our report and the number of reprint requests we have received it is doubtful that this phenomenon is as widely recognized as Bennett et al. suggest.
Charles A. Kennedy, Matthew B. Goetz, and Glenn E. Mathisen UCLA San Fernando Valley Program in Infectious Disease, UCLA School of Medicine, Los Angeles, California
References 1. Bennett JE, Kroll MR, Washburn RG. Flucytosine interference in creatinine assay. J Infect Dis 1990;162:571-2. 2. Kennedy CA, Goetz MB, Mathisen GE. Artifactual elevation of the serum creatinine in patients receiving flucytosine for cryptococcal meningitis. J Infect Dis 1989;160:1090-1. 3. Kodak EKTACHEM test methodology. Rochester, NY: Eastman Kodak, 1983. 4. Noble MA, Harper B, Grant AG, Bernstein M. Rapid determination of 5-flucytosine levels in blood. J Clin MicrobioI1984;20:996-7. 5. Washburn RG, Klym DM, Kroll MH, Bennett JE. Rapid enzymatic method for measurement of serum flucytosine levels. J Antimicrob Chemother 1986;17:673-7. 6. Huang CM, Kroll MH, Ruddel M, Washburn RG, Bennett JE. An enzymatic method for 5-flucytosine. Clin Chern 1988;34:59-62.
Downloaded from http://jid.oxfordjournals.org/ at University of Bath Library & Learning Centre on July 14, 2015
Michael A. McIlroy St. John Hospital and Medical Center, Detroit, Michigan
421
