727
Correspondence
'Departments of Internal Medicine and Clinical Pharmacy. University Hospital N(/megen, PO Box 9101. 6500 HB Nffmegen; The Netherlands; ^Department of Infectious Diseases. University Hospital Leiden, PO Box 9600. 2300 RC Leiden. The Netherlands
References Garner, J. S., Jarvii, W. R., Emori, T. G., Horan, T. C. & Hughes, J. M. (1988). CDC definitions for nosocomial infections, 1988. American Journal of Infection Control 16, 128-40. Gyssens, I. C , Leonards, C. A., Hekster, Y. A. & Van der Meer, J. W. M. (1991). Cost of antimicrobial chemotherapy. A method for global cost calculation. Pharmaceutisch Wetkblad Scientific Edition 13, 248-53. Kunin, C. M., Tupasi, T. & Craig, W. A. (1973). Use of antibiotics: a brief exposition of the problem and tome tentative solutions. Annals of Internal Medicine 79, 555-60. Moss, F., McNicol, M. W., McSwiggan, D. A. & Miller, D. L. (1981). Survey of antibiotic prescribing in a district general hospital. I. Pattern of use. Lancet ii. 349-52. Quintiliani, R., Nightingale, C. H., Crowe, H. M. t Cooper, B. W., Bartktt, R. C. & Gousse, G. (1991). Strategic antibiotic decision-making at the formulary level. Reviews of Infectious Diseases 13, Suppt. 9, S770-7. Volger, B. W., Ross, M. B., Brunetti, H. R., BaumgartneT, D. D. & Thensse, D. G. (1988). Compliance with a restricted antimicrobial agent policy in a university hospital. American Journal of Hospital Pharmacy 45, 1540-4.
SasceptibOhy of Streptococau pnewmomiae to fire antibiotics
/ Antimicrob Chemother 1992; 30: 727-728 Sir, In recent years, strains of Streptococcus pneumoniae resistant to penicillin as weD as to other antimicrobials have been detected in many parts of the world (Ward, 1981; Klugman, 1990). We have determined MICs of cefuroxime, cefotaxime, erythromycin, roxithromycin and teicoplanin by the agar dilution method (NCCLS, 1990) for 78 strains of S. pneumoniae (16 penicillin-sensitive, 50 of intermediate resistance and eight resistant) in order to establish up-to-date empirical therapeutic guidelines. The strains were isolated at the Valme Hospital (Sevilla, Spain) from different clinical samples between January 1988 and June 1991. The MICs of the antimicrobials tested are listed in the Table. The antibiotics tested showed intermediate resistance (MIC 0-11 mg/L) or were resistant (MIC > 1 mg/L) to penicillin, 22 were found to be resistant to erythromycin and roxithromycin. Hence, 35-4% of these strains were resistant to more than one antibiotic.
Downloaded from http://jac.oxfordjournals.org/ at University of Arizona on July 18, 2015
unjustified (category V). The continuation of vancomycin (ADT2) was judged by both reviewers as category IVb, c, d; the causative organism was at that time known to be sensitive toflucloxariUin.The change to fludoxacillin (ADT3) on 13 August, was right, but duration of treatment (10 days) was considered too short for 5. aureus septicaemia (category Mb). The global cost of empiric and documented therapy (ADE and ADT prescriptions), was Dfl. 1954 (£576) (Table II, left cost column). The cost of the proposed alternative agents (Aa) formulated by reviewer 1 was Dfl 1742 (£514) (Table II, right cost column). Although the proposed duration of treatment was longer, savings of at least Dfl 212 or £62 (11%) were predicted for the alternative policy in this case. To deepen the classification of Kunin we had to add supplementary (sub)categories. With the help of computer spreadsheet programs processing is not a major problem. However, long lists of categories are difficult to handle. Our flow chart systematizes and accelerates the reviewing process. Each individual drug is evaluated according to well documented parameters of antimicrobial therapy, whereas the original classification allocated complete courses in one of five broad categories, relying on the absolute authority of the infectious diseases specialist. Opinions of experts may be different, and the system nicely visualizes where they disagree. Credibility is increased by defining terms. The value of streamlining AD therapy as a tool in limiting the unnecessary use of broad spectrum AD and in cost containment (Quintiliani et al., 1991) is stressed. For presciptions judged inappropriate, alternative drug regimens and their cost can be fully formulated, thus constituting a comprehensible example of an alternative antibiotic policy for clinicians with their own patient population. Acknowledgements. Dr Peter Koopmans is gratefully acknowledged for his valuable remarks on the manuscript. INGE C. GYSSENS* PIETER J. VAN DEN BROEK* BART-JAN K.ULLBERG* YECH1EL A. HEKSTER* JOS W. M. VAN DER MEER*
Correspondence
728
Table. In vitro susceptibility of 78 (trains of S. pneumonia* Antimicrobial agent
MIC (mg/L) MIC, MIC, Range 32
32 mg/L). Combined resistance of S. pneumoniae to penicillin and erythromycin is well documented (Garda-Leoni et al., 1992). Pallares et al. (1987) showed, like us, that resistance to erythromycin is confined to penicillin-resistant strains. One-third of the latter tested here were erythromycin-resistant, so this antibiotic should not be used clinically unless strains have been shown to be sensitive to i t This also applies to roxithromycin. /J-Lactam agents are much less active against penicillin-resistant than susceptible strains (Garda-Leoni et al., 1992). Resistance to teicoplanin in strains of S. pneumoniae has not been described (Klugman, 1990). All the strains in our study were susceptible to cefuroxime, cefotaxime and teicoplanin by the NCCLS criteria. Although infections other than meningitis due to intermediate-resistant
References Aisa, M. L., Esteban, A., VUluendas, C , Lopez, C , Moles, B. & Marco, M. L. (1991). Meningitis neumococica. Revision de seis afios. Enftrmedades Infecckaas y Microbiologia Clinica 9, 277-82. Garda-Leoni, M. E., Cercenado, E., Rodefio, P., Bernaldo de Quiros, C. L., Martinez-Hernandez, D. & Bouza, E. (1992). Susceptibility of Streptococcus pneumoniae to penicillin: a prospective microbiological and clinical study. Clinical Infectious Diseases 14, 427-35. Klugman, K. P. (1990). Pneumococcal resistance to antibiotics. Clinical Microbiology Reviews 3, 171-96. National Committee for Clinical Laboratory Standards. (1990). Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aeroblcally. 2nd edn; Approved Standard M7-A2. NCCLS, Villanova, PA. Pallares, R., GudioL R, Linares, J., Ariza, J., Run, G., Murgui, L. et al. (1987). Risk factors and response to antibiotic therapy in adults with bacteremic pneumonia caused by penicillinresistant pneumococri. New England Journal of Medicine 317, 18-22. Ward, J. (1981). Antibiotic-resistant Streptococcus pneumoniae: clinical and epidemiologic aspects. Reviewi of Infectious Diseases 3, 254-66.
Downloaded from http://jac.oxfordjournals.org/ at University of Arizona on July 18, 2015
Penicillin susceptible resistant
strains of S. pneumoniae may respond to high dose of penicillin (Pallares et al., 1987), this antibiotic has not been effective in the treatment of meningitis caused by strains demonstrating any degree of resistance (Ward, 1981). Furthermore, both cefotaxime and latamoxef may also fail to treat meningitis successfully (Aisa et al., 1991). GarcJa-Lconi et al. (1992) suggest third generation cephalosporins for use against strains with penicillin MICs of < 4 mg/L. However, when strains show higher levels of resistance and in cases of CNS infection, it is necessary to use vancomycin. In our hospital, the percentage of clinically significant isolates of S. pneumoniae strains not susceptible to penicillin is 407%; the figure for erythromycin is 15%. The use of old empirical therapeutic regimens should be reconsidered and all clinically significant isolates should be submitted for antimicrobial susceptibility testing. C. FLOREZ M. J. PEREZ R-ARETIO P. PARRAS E. MARTIN Laboralorio de Mieroblologia Hospital Universitario de Vatme Cantlera de Cadiz s\n 41014 Seville. Spain
Correspondence
'Departments of Internal Medicine and Clinical Pharmacy. University Hospital N(/megen, PO Box 9101. 6500 HB Nffmegen; The Netherlands; ^Department of Infectious Diseases. University Hospital Leiden, PO Box 9600. 2300 RC Leiden. The Netherlands
References Garner, J. S., Jarvii, W. R., Emori, T. G., Horan, T. C. & Hughes, J. M. (1988). CDC definitions for nosocomial infections, 1988. American Journal of Infection Control 16, 128-40. Gyssens, I. C , Leonards, C. A., Hekster, Y. A. & Van der Meer, J. W. M. (1991). Cost of antimicrobial chemotherapy. A method for global cost calculation. Pharmaceutisch Wetkblad Scientific Edition 13, 248-53. Kunin, C. M., Tupasi, T. & Craig, W. A. (1973). Use of antibiotics: a brief exposition of the problem and tome tentative solutions. Annals of Internal Medicine 79, 555-60. Moss, F., McNicol, M. W., McSwiggan, D. A. & Miller, D. L. (1981). Survey of antibiotic prescribing in a district general hospital. I. Pattern of use. Lancet ii. 349-52. Quintiliani, R., Nightingale, C. H., Crowe, H. M. t Cooper, B. W., Bartktt, R. C. & Gousse, G. (1991). Strategic antibiotic decision-making at the formulary level. Reviews of Infectious Diseases 13, Suppt. 9, S770-7. Volger, B. W., Ross, M. B., Brunetti, H. R., BaumgartneT, D. D. & Thensse, D. G. (1988). Compliance with a restricted antimicrobial agent policy in a university hospital. American Journal of Hospital Pharmacy 45, 1540-4.
SasceptibOhy of Streptococau pnewmomiae to fire antibiotics
/ Antimicrob Chemother 1992; 30: 727-728 Sir, In recent years, strains of Streptococcus pneumoniae resistant to penicillin as weD as to other antimicrobials have been detected in many parts of the world (Ward, 1981; Klugman, 1990). We have determined MICs of cefuroxime, cefotaxime, erythromycin, roxithromycin and teicoplanin by the agar dilution method (NCCLS, 1990) for 78 strains of S. pneumoniae (16 penicillin-sensitive, 50 of intermediate resistance and eight resistant) in order to establish up-to-date empirical therapeutic guidelines. The strains were isolated at the Valme Hospital (Sevilla, Spain) from different clinical samples between January 1988 and June 1991. The MICs of the antimicrobials tested are listed in the Table. The antibiotics tested showed intermediate resistance (MIC 0-11 mg/L) or were resistant (MIC > 1 mg/L) to penicillin, 22 were found to be resistant to erythromycin and roxithromycin. Hence, 35-4% of these strains were resistant to more than one antibiotic.
Downloaded from http://jac.oxfordjournals.org/ at University of Arizona on July 18, 2015
unjustified (category V). The continuation of vancomycin (ADT2) was judged by both reviewers as category IVb, c, d; the causative organism was at that time known to be sensitive toflucloxariUin.The change to fludoxacillin (ADT3) on 13 August, was right, but duration of treatment (10 days) was considered too short for 5. aureus septicaemia (category Mb). The global cost of empiric and documented therapy (ADE and ADT prescriptions), was Dfl. 1954 (£576) (Table II, left cost column). The cost of the proposed alternative agents (Aa) formulated by reviewer 1 was Dfl 1742 (£514) (Table II, right cost column). Although the proposed duration of treatment was longer, savings of at least Dfl 212 or £62 (11%) were predicted for the alternative policy in this case. To deepen the classification of Kunin we had to add supplementary (sub)categories. With the help of computer spreadsheet programs processing is not a major problem. However, long lists of categories are difficult to handle. Our flow chart systematizes and accelerates the reviewing process. Each individual drug is evaluated according to well documented parameters of antimicrobial therapy, whereas the original classification allocated complete courses in one of five broad categories, relying on the absolute authority of the infectious diseases specialist. Opinions of experts may be different, and the system nicely visualizes where they disagree. Credibility is increased by defining terms. The value of streamlining AD therapy as a tool in limiting the unnecessary use of broad spectrum AD and in cost containment (Quintiliani et al., 1991) is stressed. For presciptions judged inappropriate, alternative drug regimens and their cost can be fully formulated, thus constituting a comprehensible example of an alternative antibiotic policy for clinicians with their own patient population. Acknowledgements. Dr Peter Koopmans is gratefully acknowledged for his valuable remarks on the manuscript. INGE C. GYSSENS* PIETER J. VAN DEN BROEK* BART-JAN K.ULLBERG* YECH1EL A. HEKSTER* JOS W. M. VAN DER MEER*
Correspondence
728
Table. In vitro susceptibility of 78 (trains of S. pneumonia* Antimicrobial agent
MIC (mg/L) MIC, MIC, Range 32
32 mg/L). Combined resistance of S. pneumoniae to penicillin and erythromycin is well documented (Garda-Leoni et al., 1992). Pallares et al. (1987) showed, like us, that resistance to erythromycin is confined to penicillin-resistant strains. One-third of the latter tested here were erythromycin-resistant, so this antibiotic should not be used clinically unless strains have been shown to be sensitive to i t This also applies to roxithromycin. /J-Lactam agents are much less active against penicillin-resistant than susceptible strains (Garda-Leoni et al., 1992). Resistance to teicoplanin in strains of S. pneumoniae has not been described (Klugman, 1990). All the strains in our study were susceptible to cefuroxime, cefotaxime and teicoplanin by the NCCLS criteria. Although infections other than meningitis due to intermediate-resistant
References Aisa, M. L., Esteban, A., VUluendas, C , Lopez, C , Moles, B. & Marco, M. L. (1991). Meningitis neumococica. Revision de seis afios. Enftrmedades Infecckaas y Microbiologia Clinica 9, 277-82. Garda-Leoni, M. E., Cercenado, E., Rodefio, P., Bernaldo de Quiros, C. L., Martinez-Hernandez, D. & Bouza, E. (1992). Susceptibility of Streptococcus pneumoniae to penicillin: a prospective microbiological and clinical study. Clinical Infectious Diseases 14, 427-35. Klugman, K. P. (1990). Pneumococcal resistance to antibiotics. Clinical Microbiology Reviews 3, 171-96. National Committee for Clinical Laboratory Standards. (1990). Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aeroblcally. 2nd edn; Approved Standard M7-A2. NCCLS, Villanova, PA. Pallares, R., GudioL R, Linares, J., Ariza, J., Run, G., Murgui, L. et al. (1987). Risk factors and response to antibiotic therapy in adults with bacteremic pneumonia caused by penicillinresistant pneumococri. New England Journal of Medicine 317, 18-22. Ward, J. (1981). Antibiotic-resistant Streptococcus pneumoniae: clinical and epidemiologic aspects. Reviewi of Infectious Diseases 3, 254-66.
Downloaded from http://jac.oxfordjournals.org/ at University of Arizona on July 18, 2015
Penicillin susceptible resistant
strains of S. pneumoniae may respond to high dose of penicillin (Pallares et al., 1987), this antibiotic has not been effective in the treatment of meningitis caused by strains demonstrating any degree of resistance (Ward, 1981). Furthermore, both cefotaxime and latamoxef may also fail to treat meningitis successfully (Aisa et al., 1991). GarcJa-Lconi et al. (1992) suggest third generation cephalosporins for use against strains with penicillin MICs of < 4 mg/L. However, when strains show higher levels of resistance and in cases of CNS infection, it is necessary to use vancomycin. In our hospital, the percentage of clinically significant isolates of S. pneumoniae strains not susceptible to penicillin is 407%; the figure for erythromycin is 15%. The use of old empirical therapeutic regimens should be reconsidered and all clinically significant isolates should be submitted for antimicrobial susceptibility testing. C. FLOREZ M. J. PEREZ R-ARETIO P. PARRAS E. MARTIN Laboralorio de Mieroblologia Hospital Universitario de Vatme Cantlera de Cadiz s\n 41014 Seville. Spain
