Postgraduate Medicine
ISSN: 0032-5481 (Print) 1941-9260 (Online) Journal homepage: http://www.tandfonline.com/loi/ipgm20
Cases 11, 12, and 13 James J. Rahal Jr & Michael S. Simberkoff To cite this article: James J. Rahal Jr & Michael S. Simberkoff (1977) Cases 11, 12, and 13, Postgraduate Medicine, 62:6, 125-127, DOI: 10.1080/00325481.1977.11714707 To link to this article: http://dx.doi.org/10.1080/00325481.1977.11714707
Published online: 07 Jul 2016.
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Date: 25 August 2017, At: 21:48
antibiotics how to use them ln 19n-1978 special series
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11
Recurrent Urlnary Tract Infection
Dr Michael S. Simberkoff: In six years a 55-year-old man bas bad four episodes of urinary tract infection manifested by dysuria and frequency. Each time he bas been treated with a two-week course of ampicillin, to which the organism bas been sensitive. Physical examination shows the prostate to be enlarged but not tender. There is no prostatic exudate following massage. No calculi are visible on pelvic x-ray films. An intravenous pyelogram does not show structural abnormalities or obstruction in the urinary tract. There is a slight increase in the postvoiding residual volume of urine in the bladder. The patient again responds to a two-week course of ampicillin, to which the urinary organism (Proteus mirabilis) is sensitive in vitro.
cases 11 , 12, and 13 James J. Rahal, Jr, MD Michael S. Slmberkoff, MD New York University School of Medicine New York Self-assessment case studies illustrating prudent selection of antimicrobial agents in recurrent urinary tract infection, urinary frequency in a diabetic, and urinary tract infection without significant bacteriuria
Q Which of the following antibiotics should be used for long-term (two-year) suppressive therapy?
a. Ampicillin b. Cephalexin c. Trimethoprim with sulfamethoxazole
d. Sulfamethizole e. Nitrofurantoin
Dr James J. Rahal, Jr: The answer is nitrofurantoin (e). Chronic urinary tract infection in males bas been shown to improve with the use of nitrofurantoin or methenamine mandelate for long-term suppressive antimicrobial therapy. This improvement is primarily a decrease in morbidity, with fewer acute exacerbations of the infection and with extension of the time between recurrences, as measured by positive urine cultures. After a 10- to 14-day course of specifie antimicrobial therapy with ampicillin or cephalexin (if the organism is sensitive to one of these), treatment with a drug such as nitrofurantoin or methenamine mandelate for one to two years is indicated, particularly for those with multiple acute episodes, stones, or obstruction. More potent antibiotics like the aminoglycosides Adapted from a course presented at New York University Post-Graduate Medical School, New York. Dr Rahal, associate professor of medicine, and Dr Simberkoff, assistant professor of medicine, New York University School of Medicine, New York, were codirectors of the course.
Vol. 82 • No. 8 • o-Tiber 1977 • POSTGAADUATE MEDICINE
125
antlbiotics - - - - - - - - - - - - - - - - - - - - - - · Every effort must be made to avoid undesirable drug interactions in patients receiving bOth an antibiotic and other medication.
should be reserved for acute exacerbations of urinary tract infection. If chronic infection of the prostate is present, trimethoprim with sulfamethoxazole is the drug of choice. Trimethoprim is one of the few agents that penetrate the prostate, and it is active against Gram-negative bacilli.
12
Urlnary Frequency in a Dlabetlc
Downloaded by [Australian Catholic University] at 21:48 25 August 2017
Dr Rahal: A 44-year-old diabetic woman on tolbutamide therapy cornes to the office because of urinary frequency. Findings at physical examination are unremarkable. Urinalysis shows a glucose reaction of 1+, no protein, and no acetone. The urine contains 15 to 20 WBCs/hpf, and no pathogenic organisms are detected.
on the function of the eighth cranial nerve must also be remembered. Both ethacrynic acid and furosemide may produce cochlear dysfunction. If either is used with an aminoglycoside, the potential for ototoxicity may be increased.
Tract Infection 13 Urinary Wlthout Significant Bacteriuria Dr Simberkoff: A 45-year-old woman with a history of recurrent urinary tract infection corn plains of urinary frequency and urgency. Her temperature is 100.6 F, the urinary sediment contains 15 WBCs/hpf, and the laboratory reports that two cultures show "insignificant growth-less than 100,000 organisms/ml." Q Bacteriuria with more than 100,000
Q Which of the following antibiotics should not be administered to this patient? a. Ampicillin b. Cephalexin c. Trimethoprim with sulfamethoxazole d. Tetracycline
organisms/ml is not a necessary criterion for diagnosing urinary tract infection caused by which of the following organisms? a. Proteus mirabilis b. Escherichia coli c. Enterococcus d. Pseudomonas aeruginosa
Dr Simberkoff: The correct answer is trimethoprim with sulfamethoxazole (c). Sulfonamides displace tolbutamide from serum protein-binding sites and th us may increase its hypoglycemie activity. Every effort must be made to avoid undesirable drug interactions in patients receiving both an antibiotic and other medication. The use of broad-spectrum antibiotics should be avoided in those who are receiving warfarin. These antibiotics inhibit intestinal flora, thus limiting the synthesis of vitamin K and potentiating anticoagulant activity of warfarin. Sulfonamides also interact with warfarin, displacing it from binding site with albumen and increasing its anticoagulant activity. Sulfonamides also displace bilirubin from its binding site. Thus, sulfonamide administration during pregnancy increases the risk of kernicterus in the infant after birth. The combined effect of diuretics and aminoglycosides
126
Dr Rahal: The answer is enterococcus (c), a group that includes Streptococcus faecalis. Enterococcus may produce urinary tract infection with bacteriuria of 100,000 organisms/ml or more, but it is important to remember that this organism may be the cause oftrue infection when the count is lower. The original studies defining 100,000 organisms/ml as a significant cutoff point for the diagnosis of urinary tract infection were done in the 1950s to elucidate factors important in diagnosing Gram-negative urinary tract infections, namely, those due to the Enterobacteriaceae. These studies did not include Gram-positive enterococcal infection. When a urine culture yields enterococci in a concentration of Jess than 100,000/ml, Gram staining is helpful in confirming the presence ofthese organisms; a second culture should be obtained to rule out superficial contamina-
POSTGAADUATE MEDICINE • December 19n • Vol. 82 •
No. 6
Downloaded by [Australian Catholic University] at 21:48 25 August 2017
tion. If it shows a moderately high count of organisms (10,000 to 100,000/ml) in association with urinary tract symptoms, specifie treatment may be indicated. Another organism recent! y shown to cause urinary tract infection with variable numbers of organisms in the urine, particularly in young women, is Staphylococcus epidermidis. The total colony count of S epidermidis need not be 100,000 organisms/ml or more to define the presence of urinary tract infection. However, two or more positive cultures plus a Gram stain should confirm the presence of this organism.
Q Which of the following antibiotics is preferred for oral treatment of enterococcal urinary tract infection? a. Cephalexin c. Tetracycline b. Ampicillin d. Clindamycin
Dr Rahal: The answer is ampicillin (b). Enterococcus is resistant to many commonly used antibiotics. Clindamycin is ineffective against enterococcus, and tetracycline and cephalexin have limited activity against this organism. Ampicillin is the most effective and !east toxic single antibiotic available for the treatment of enterococcal urinary tract infection. In patients with penicillin allergy an alternative antibiotic for infections which may be treated orally is erythromycin. Q Which of the following organisms may cause urine to become alkaline? a. E coli c. Pseudomonas b. Proteus d. Klebsiel/a Dr Simberkoff: The answers are Proteus (b) and Klebsiella (d). Both produce urease, which splits urea into its components, ammonium and carbon dioxide. E coli and Pseudomonas species do not produce urease; they metabolize glucose in the urine and thus turn the urine acid. Q Which of the following antibiotics is most often effective in treating indole-positive Proteus and
Vol. 62 • No. 6 • December 19n • POSTGRADUATE MEDICINE
Pseudomonas urinary tract infections? a. Ampicillin b. Cephalexin c. Sulfisoxazole d. Carbenicillin indanyl sodium Dr SimberkotT: The answer is carbenicillin indanyl sodium (d). Ampicillin and cephalexin are effective against P mirabilis species but are virtually inactive against other Proteus and Pseudomonas species. Sulfisoxazole is active against many Proteus species but has limited activity against Pseudomonas. Carbenicillin indanyl sodium is active against both Proteus and Pseudomonas and th us may be used in patients in whom one of these organisms is proved to be the cause ofurinary tract infection.
Q Which of the following antibiotics is most often effective in treating urinary tract infection caused by Klebsiella? a. Ampicillin b. Cephalexin c. Sulfonamide compounds d. Carbenicillin indanyl sodium
Dr Rahal: The answer is cephalexin (b). Ampicillin is generally ineffective against most strains of Klebsiella. Sulfonamide compounds may suppress any of a wide variety of Gram-negative bacilli and may in fact be effective against sorne strains of Klebsiella. On the other band, carbenicillin indanyl sodium, an antibiotic with a wide Gram-negative spectrum, is ineffective against Klebsiella species; this antibiotic should never be used, orally or parenterally, for the treatment of Klebsiella infection. Of the antimicrobial drugs mentioned, the cephalosporins are the most active against Klebsiel/a. • Address reprint requests to James J. Ra hal. Jr. MD. Division of Infectious Disease, Veterans Administration Hospital. First Ave at E 24th St, New York. NY 10010.
CORRECTION In the second article in this series, appearing in the October issue, the photomicrographs in figures 2 (page 187) and 3 (page 188) were transposed.
127
ISSN: 0032-5481 (Print) 1941-9260 (Online) Journal homepage: http://www.tandfonline.com/loi/ipgm20
Cases 11, 12, and 13 James J. Rahal Jr & Michael S. Simberkoff To cite this article: James J. Rahal Jr & Michael S. Simberkoff (1977) Cases 11, 12, and 13, Postgraduate Medicine, 62:6, 125-127, DOI: 10.1080/00325481.1977.11714707 To link to this article: http://dx.doi.org/10.1080/00325481.1977.11714707
Published online: 07 Jul 2016.
Submit your article to this journal
View related articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ipgm20 Download by: [Australian Catholic University]
Date: 25 August 2017, At: 21:48
antibiotics how to use them ln 19n-1978 special series
Downloaded by [Australian Catholic University] at 21:48 25 August 2017
11
Recurrent Urlnary Tract Infection
Dr Michael S. Simberkoff: In six years a 55-year-old man bas bad four episodes of urinary tract infection manifested by dysuria and frequency. Each time he bas been treated with a two-week course of ampicillin, to which the organism bas been sensitive. Physical examination shows the prostate to be enlarged but not tender. There is no prostatic exudate following massage. No calculi are visible on pelvic x-ray films. An intravenous pyelogram does not show structural abnormalities or obstruction in the urinary tract. There is a slight increase in the postvoiding residual volume of urine in the bladder. The patient again responds to a two-week course of ampicillin, to which the urinary organism (Proteus mirabilis) is sensitive in vitro.
cases 11 , 12, and 13 James J. Rahal, Jr, MD Michael S. Slmberkoff, MD New York University School of Medicine New York Self-assessment case studies illustrating prudent selection of antimicrobial agents in recurrent urinary tract infection, urinary frequency in a diabetic, and urinary tract infection without significant bacteriuria
Q Which of the following antibiotics should be used for long-term (two-year) suppressive therapy?
a. Ampicillin b. Cephalexin c. Trimethoprim with sulfamethoxazole
d. Sulfamethizole e. Nitrofurantoin
Dr James J. Rahal, Jr: The answer is nitrofurantoin (e). Chronic urinary tract infection in males bas been shown to improve with the use of nitrofurantoin or methenamine mandelate for long-term suppressive antimicrobial therapy. This improvement is primarily a decrease in morbidity, with fewer acute exacerbations of the infection and with extension of the time between recurrences, as measured by positive urine cultures. After a 10- to 14-day course of specifie antimicrobial therapy with ampicillin or cephalexin (if the organism is sensitive to one of these), treatment with a drug such as nitrofurantoin or methenamine mandelate for one to two years is indicated, particularly for those with multiple acute episodes, stones, or obstruction. More potent antibiotics like the aminoglycosides Adapted from a course presented at New York University Post-Graduate Medical School, New York. Dr Rahal, associate professor of medicine, and Dr Simberkoff, assistant professor of medicine, New York University School of Medicine, New York, were codirectors of the course.
Vol. 82 • No. 8 • o-Tiber 1977 • POSTGAADUATE MEDICINE
125
antlbiotics - - - - - - - - - - - - - - - - - - - - - - · Every effort must be made to avoid undesirable drug interactions in patients receiving bOth an antibiotic and other medication.
should be reserved for acute exacerbations of urinary tract infection. If chronic infection of the prostate is present, trimethoprim with sulfamethoxazole is the drug of choice. Trimethoprim is one of the few agents that penetrate the prostate, and it is active against Gram-negative bacilli.
12
Urlnary Frequency in a Dlabetlc
Downloaded by [Australian Catholic University] at 21:48 25 August 2017
Dr Rahal: A 44-year-old diabetic woman on tolbutamide therapy cornes to the office because of urinary frequency. Findings at physical examination are unremarkable. Urinalysis shows a glucose reaction of 1+, no protein, and no acetone. The urine contains 15 to 20 WBCs/hpf, and no pathogenic organisms are detected.
on the function of the eighth cranial nerve must also be remembered. Both ethacrynic acid and furosemide may produce cochlear dysfunction. If either is used with an aminoglycoside, the potential for ototoxicity may be increased.
Tract Infection 13 Urinary Wlthout Significant Bacteriuria Dr Simberkoff: A 45-year-old woman with a history of recurrent urinary tract infection corn plains of urinary frequency and urgency. Her temperature is 100.6 F, the urinary sediment contains 15 WBCs/hpf, and the laboratory reports that two cultures show "insignificant growth-less than 100,000 organisms/ml." Q Bacteriuria with more than 100,000
Q Which of the following antibiotics should not be administered to this patient? a. Ampicillin b. Cephalexin c. Trimethoprim with sulfamethoxazole d. Tetracycline
organisms/ml is not a necessary criterion for diagnosing urinary tract infection caused by which of the following organisms? a. Proteus mirabilis b. Escherichia coli c. Enterococcus d. Pseudomonas aeruginosa
Dr Simberkoff: The correct answer is trimethoprim with sulfamethoxazole (c). Sulfonamides displace tolbutamide from serum protein-binding sites and th us may increase its hypoglycemie activity. Every effort must be made to avoid undesirable drug interactions in patients receiving both an antibiotic and other medication. The use of broad-spectrum antibiotics should be avoided in those who are receiving warfarin. These antibiotics inhibit intestinal flora, thus limiting the synthesis of vitamin K and potentiating anticoagulant activity of warfarin. Sulfonamides also interact with warfarin, displacing it from binding site with albumen and increasing its anticoagulant activity. Sulfonamides also displace bilirubin from its binding site. Thus, sulfonamide administration during pregnancy increases the risk of kernicterus in the infant after birth. The combined effect of diuretics and aminoglycosides
126
Dr Rahal: The answer is enterococcus (c), a group that includes Streptococcus faecalis. Enterococcus may produce urinary tract infection with bacteriuria of 100,000 organisms/ml or more, but it is important to remember that this organism may be the cause oftrue infection when the count is lower. The original studies defining 100,000 organisms/ml as a significant cutoff point for the diagnosis of urinary tract infection were done in the 1950s to elucidate factors important in diagnosing Gram-negative urinary tract infections, namely, those due to the Enterobacteriaceae. These studies did not include Gram-positive enterococcal infection. When a urine culture yields enterococci in a concentration of Jess than 100,000/ml, Gram staining is helpful in confirming the presence ofthese organisms; a second culture should be obtained to rule out superficial contamina-
POSTGAADUATE MEDICINE • December 19n • Vol. 82 •
No. 6
Downloaded by [Australian Catholic University] at 21:48 25 August 2017
tion. If it shows a moderately high count of organisms (10,000 to 100,000/ml) in association with urinary tract symptoms, specifie treatment may be indicated. Another organism recent! y shown to cause urinary tract infection with variable numbers of organisms in the urine, particularly in young women, is Staphylococcus epidermidis. The total colony count of S epidermidis need not be 100,000 organisms/ml or more to define the presence of urinary tract infection. However, two or more positive cultures plus a Gram stain should confirm the presence of this organism.
Q Which of the following antibiotics is preferred for oral treatment of enterococcal urinary tract infection? a. Cephalexin c. Tetracycline b. Ampicillin d. Clindamycin
Dr Rahal: The answer is ampicillin (b). Enterococcus is resistant to many commonly used antibiotics. Clindamycin is ineffective against enterococcus, and tetracycline and cephalexin have limited activity against this organism. Ampicillin is the most effective and !east toxic single antibiotic available for the treatment of enterococcal urinary tract infection. In patients with penicillin allergy an alternative antibiotic for infections which may be treated orally is erythromycin. Q Which of the following organisms may cause urine to become alkaline? a. E coli c. Pseudomonas b. Proteus d. Klebsiel/a Dr Simberkoff: The answers are Proteus (b) and Klebsiella (d). Both produce urease, which splits urea into its components, ammonium and carbon dioxide. E coli and Pseudomonas species do not produce urease; they metabolize glucose in the urine and thus turn the urine acid. Q Which of the following antibiotics is most often effective in treating indole-positive Proteus and
Vol. 62 • No. 6 • December 19n • POSTGRADUATE MEDICINE
Pseudomonas urinary tract infections? a. Ampicillin b. Cephalexin c. Sulfisoxazole d. Carbenicillin indanyl sodium Dr SimberkotT: The answer is carbenicillin indanyl sodium (d). Ampicillin and cephalexin are effective against P mirabilis species but are virtually inactive against other Proteus and Pseudomonas species. Sulfisoxazole is active against many Proteus species but has limited activity against Pseudomonas. Carbenicillin indanyl sodium is active against both Proteus and Pseudomonas and th us may be used in patients in whom one of these organisms is proved to be the cause ofurinary tract infection.
Q Which of the following antibiotics is most often effective in treating urinary tract infection caused by Klebsiella? a. Ampicillin b. Cephalexin c. Sulfonamide compounds d. Carbenicillin indanyl sodium
Dr Rahal: The answer is cephalexin (b). Ampicillin is generally ineffective against most strains of Klebsiella. Sulfonamide compounds may suppress any of a wide variety of Gram-negative bacilli and may in fact be effective against sorne strains of Klebsiella. On the other band, carbenicillin indanyl sodium, an antibiotic with a wide Gram-negative spectrum, is ineffective against Klebsiella species; this antibiotic should never be used, orally or parenterally, for the treatment of Klebsiella infection. Of the antimicrobial drugs mentioned, the cephalosporins are the most active against Klebsiel/a. • Address reprint requests to James J. Ra hal. Jr. MD. Division of Infectious Disease, Veterans Administration Hospital. First Ave at E 24th St, New York. NY 10010.
CORRECTION In the second article in this series, appearing in the October issue, the photomicrographs in figures 2 (page 187) and 3 (page 188) were transposed.
127
