Efficacy of a Twelve-Hourly Ceftriaxone Regimen in the Treatment of Serious Bacterial Infections

Similar documents
Efficacy of Ceftriaxone in Serious Bacterial Infections

Ceftriaxone (Ro ) Therapy of Serious Infection

Pharmacological Evaluation of Amikacin in Neonates

In Vitro Antimicrobial Activity of CP-99,219, a Novel Azabicyclo-Naphthyridone

See Important Reminder at the end of this policy for important regulatory and legal information.

Mercy Medical Center Des Moines, Iowa Department of Pathology. Microbiology Department Antibiotic Susceptibility January December 2016

Similar to Penicillins: -Chemically. -Mechanism of action. -Toxicity.

Source: Portland State University Population Research Center (

Appropriate Management of Common Pediatric Infections. Blaise L. Congeni M.D. Akron Children s Hospital Division of Pediatric Infectious Diseases

Appropriate antimicrobial therapy in HAP: What does this mean?

Aberdeen Hospital. Antibiotic Susceptibility Patterns For Commonly Isolated Organisms For 2015

These recommendations were approved for use by the Pharmaceutical and Therapeutics Committee, RCWMCH on 1 February 2017.

Treatment of Respiratory Tract Infections Prof. Mohammad Alhumayyd Dr. Aliah Alshanwani

Appropriate Antimicrobial Therapy for Treatment of

General Approach to Infectious Diseases

ECOLOGICAL IMPACT OF NARROW SPECTRUM ANTIMICROBIAL AGENTS COMPARED TO BROAD SPECTRUM AGENTS ON THE HUMAN INTESTINAL MICROFLORA CARL ERIK NORD

Childrens Hospital Antibiogram for 2012 (Based on data from 2011)

USA Product Label CLINTABS TABLETS. Virbac. brand of clindamycin hydrochloride tablets. ANADA # , Approved by FDA DESCRIPTION

Comparative Activity of Netilmicin, Gentamicin, Amikacin, and Tobramycin Against Pseudomonas aeruginosa and Enterobacteriaceae

Cipro for gram positive cocci in urine

Empiric Treatment of Sepsis. Professor of Clinical Microbiology Department of Microbiology Leicester University U. K.

Central Nervous System Infections

Scottish Medicines Consortium

Aminoglycoside-resistant enterococci

VCH PHC SURGICAL PROPHYLAXIS RECOMMENDATIONS

Introduction to Pharmacokinetics and Pharmacodynamics

Int.J.Curr.Microbiol.App.Sci (2017) 6(3):

Northwestern Medicine Central DuPage Hospital Antimicrobial Criteria Updated 11/16/16

Other Beta - lactam Antibiotics

Prophylactic antibiotic timing and dosage. Dr. Sanjeev Singh AIMS, Kochi

The β- Lactam Antibiotics. Munir Gharaibeh MD, PhD, MHPE School of Medicine, The University of Jordan November 2018

Antibiotics. Antimicrobial Drugs. Alexander Fleming 10/18/2017

ESBL Producers An Increasing Problem: An Overview Of An Underrated Threat

available. and P. aeruginosa resistant to gentamicin by standardized disk testing (1) in the Microbiology Laboratory

مادة االدوية المرحلة الثالثة م. غدير حاتم محمد

Prevalence of Extended Spectrum Beta- Lactamase Producers among Various Clinical Samples in a Tertiary Care Hospital: Kurnool District, India

4 th and 5 th generation cephalosporins. Naderi HR Associate professor of Infectious Diseases

Interactive session: adapting to antibiogram. Thong Phe Heng Vengchhun Felix Leclerc Erika Vlieghe

Disk Susceptibility Studies with Cefazolin and Cephalothin

In Vitro Activity of Netilmicin, Gentamicin, and Amikacin

Selective toxicity. Antimicrobial Drugs. Alexander Fleming 10/17/2016

Lab Exercise: Antibiotics- Evaluation using Kirby Bauer method.

Pharmacology Week 6 ANTIMICROBIAL AGENTS

A retrospective analysis of urine culture results issued by the microbiology department, Teaching Hospital, Karapitiya

Synergism of penicillin or ampicillin combined with sissomicin or netilmicin against enterococci

Comparison of Clindamycin, Erythromycin, and Methicillin in Streptococcal Infections in Monkeys

EXTENDED-SPECTRUM BETA-LACTAMASE (ESBL) TESTING

ANTIBIOTICS USED FOR RESISTACE BACTERIA. 1. Vancomicin

Safe Patient Care Keeping our Residents Safe Use Standard Precautions for ALL Residents at ALL times

Guidelines for Laboratory Verification of Performance of the FilmArray BCID System

GENTAMICIN: ACTIVITY IN VITRO AGAINST GRAMNEGATIVE ORGANISMS AND CLINICAL EXPERIENCES IN THE TREATMENT OF URINARY TRACT INFECTIONS

Intra-Abdominal Infections. Jessica Thompson, PharmD, BCPS (AQ-ID) Infectious Diseases Pharmacy Clinical Specialist Renown Health April 19, 2018

against Clinical Isolates of Gram-Positive Bacteria

PDF hosted at the Radboud Repository of the Radboud University Nijmegen

DETERMINING CORRECT DOSING REGIMENS OF ANTIBIOTICS BASED ON THE THEIR BACTERICIDAL ACTIVITY*

Drug Class Prior Authorization Criteria Intravenous Antibiotics

Tel: Fax:

The Basics: Using CLSI Antimicrobial Susceptibility Testing Standards

University, New York, New York Received for publication 7 May was measured by the broth dilution method as previously

Antibiotic Stewardship Program (ASP) CHRISTUS SETX

11/10/2016. Skin and Soft Tissue Infections. Disclosures. Educational Need/Practice Gap. Objectives. Case #1

2 0 hr. 2 hr. 4 hr. 8 hr. 10 hr. 12 hr.14 hr. 16 hr. 18 hr. 20 hr. 22 hr. 24 hr. (time)

General Surgery Small Group Activity (Facilitator Notes) Curriculum for Antimicrobial Stewardship

Diagnosis: Presenting signs and Symptoms include:

Prevalence of Metallo-Beta-Lactamase Producing Pseudomonas aeruginosa and its antibiogram in a tertiary care centre

6.0 ANTIBACTERIAL ACTIVITY OF CAROTENOID FROM HALOMONAS SPECIES AGAINST CHOSEN HUMAN BACTERIAL PATHOGENS

Antimicrobial susceptibility

GUIDELINES FOR THE MANAGEMENT OF COMMUNITY-ACQUIRED PNEUMONIA IN ADULTS

Antibiotic. Antibiotic Classes, Spectrum of Activity & Antibiotic Reporting

Antibiotics & treatment of Acute Bcterial Sinusitis. Walid Reda Product Manager. Do your antimicrobial options meet your needs?

Original Article. Ratri Hortiwakul, M.Sc.*, Pantip Chayakul, M.D.*, Natnicha Ingviya, B.Sc.**

2012 ANTIBIOGRAM. Central Zone Former DTHR Sites. Department of Pathology and Laboratory Medicine

Protein Synthesis Inhibitors

Chapter 51. Clinical Use of Antimicrobial Agents

Antimicrobial Pharmacodynamics

Duke University Hospital Guideline for Empiric Inpatient Treatment of Cancer- Related Neutropenic Fever in Adult Patients

Antibacterial susceptibility testing

USA Product Label LINCOCIN. brand of lincomycin hydrochloride tablets. brand of lincomycin hydrochloride injection, USP. For Use in Animals Only

Antibiotic Abyss. Discussion Points. MRSA Treatment Guidelines

Initial Management of Infections in the Era of Enhanced Antimicrobial Resistance

Burn Infection & Laboratory Diagnosis

Randomized Controlled Trial on Adjunctive Lavage for Severe Peritoneal Dialysis- Related Peritonitis

Suggestions for appropriate agents to include in routine antimicrobial susceptibility testing

Help with moving disc diffusion methods from BSAC to EUCAST. Media BSAC EUCAST

The Nuts and Bolts of Antibiograms in Long-Term Care Facilities

Treatment of septic peritonitis

MICHAEL J. RYBAK,* ELLIE HERSHBERGER, TABITHA MOLDOVAN, AND RICHARD G. GRUCZ

PRACTIC GUIDELINES for APPROPRIATE ANTIBIOTICS USE

Tobramycin. Received for publication 5 December 1974

Bactericidal and Bacteriostatic Action of Chloramphenicol

Principles of Anti-Microbial Therapy Assistant Professor Naza M. Ali. Lec 1

Bacterial Pathogens in Urinary Tract Infection and Antibiotic Susceptibility Pattern from a Teaching Hospital, Bengaluru, India

Felipe N. Gutierrez MD, MPH Chief, Infectious Diseases Phoenix VA Healthcare

GASTRO-INTESTINAL TRACT INFECTIONS - ANTIMICROBIAL MANAGEMENT

Safety of an Out-Patient Intravenous Antibiotics Programme

RELIABLE AND REALISTIC APPROACH TO SENSITIVITY TESTING

Antibiotic stewardship in long term care

THERAPY OF ANAEROBIC INFECTIONS LUNG ABSCESS BRAIN ABSCESS

Emergence of Gentamicin- and Carbenicillin-Resistant Pseudomonas aeruginosa in a Hospital Environment

International Journal of Advances in Pharmacy and Biotechnology Vol.3, Issue-2, 2017, 1-7 Research Article Open Access.

Transcription:

ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, July 1982, p. 1-17 66-484/82/71-5$2./ Vol. 22, No. 1 Efficacy of a Telve-Hourly Ceftriaxone Regimen in the Treatment of Serious Bacterial Infections MELANIE J. MASLOW,* JEROME F. LEVINE, ALAN A. POLLOCK, MICHAEL S. SIMBERKOFF, AND JAMES J. RAHAL, JR. Infectious Disease Section, Ne York Veterans Administration Medical Center, and Department of Medicine, Ne York University School of Medicine, Ne York, Ne York 11 Received 25 January 1982/Accepted 19 April 1982 Eighteen patients ith 21 serious infections ere treated ith ceftriaxone, 1 g intravenously every 12 h, for a mean duration of 8 days. Eighteen gram-negative and to gram-positive organisms ere isolated. Sites of infection included blood (three patients), urinary tract (six patients), respiratory tract (seven patients), biliary tract (three patients), ascitic fluid (one patient), and skin (one patient). Serum, bile, and ascitic fluid concentrations of ceftriaxone ere in excess of the minimal bactericidal concentration required for the infecting organism in all cases. A bacteriological response as demonstrated in 94% of the infections. A clinical response occurred in four infections from hich no pathogens ere recovered. In one patient, ceftriaxone failed to eradicate a peritoneal infection due to Bacteroides fragilis. In to patients, superinfection ith enterococci developed both during and after therapy. Systemic tolerance to ceftriaxone as excellent. Ceftriaxone (Ro 1-994) is a ne parenteral cephalosporin hich is stable against P-lactamases and has enhanced activity against a ide range of organisms, including Enterobacteriaceae, Haemophilus influenzae, Neisseria species, and non-enterococcal streptococci (1,, 5, 9, 11). Pharmacokinetic data from humans sho that ceftriaxone, as compared ith other cephalosporins, has an unusually long half-life of 6 to 8 h (7, 8; A. Pollock, P. Tee, I. Patel, J. Spicehandler, M. Simberkoff, and J. Rahal, Program Abstr. Intersci. Conf. Antimicrob. Agents Chemother. 21st, Chicago, Ill., abstr. no. 86, 1981), alloing extension of the dosage interval to 12 h. This report details the results of therapy ith ceftriaxone, administered every 12 h, in 18 patients ith acute bacterial infections. 1 MATERIALS AND METHODS Eighteen males, 5 to 8 years of age, ere treated ith ceftriaxone for suspected or documepted acute bacterial infections. Most of these patients had underlying diseases such as diabetes, cirrhosis, atherosclerotic heart disease, chronic obstructive pulmonary disease, and malignant disease. Ceftriaxone as administered as a -min intravenous infusion at a dose of 1 g every 12 h for a mean duration of 8 days (range, to 14 days). One patient (patient 15) ith pneumonia caused by to gram-negative organisms received a larger dose (2 g every 12 h) because of overhelming disease. Patients ith bacteremia had at least one positive blood culture in association ith chills and fever. Those ith pneumonia had radiographic infiltrates and both leukocytes and bacteria on Gram stains of deepsuctioned sputum. Urinary tract infection as defined by the presence of >15 organisms per ml of urine ith associated pyuria. Cirrhotic patients ith peritonitis had ascitic fluid leukocytosis (> leukocytes per ml) and a positive culture from this fluid. Cholecystitis as defined as right upper quadrant pain in association ith fever, leukocytosis, and cholelithiasis, as demonstrated by ultrasound, radioisotope scan, or endoscopy. The diagnosis of skin infection as based on local suppuration, induration, a positive Gram stain of the exudate, and a positive culture. Appropriate cultures ere obtained before therapy, 48 h after therapy as begun, and after treatment as completed. Additional cultures ere obtained 4 to 6 eeks after treatment from patients ith urinary tract infections. Bacteriological response as defined as elimination of the initial pathogen ithin 48 h after therapy as begun and for the duration of the folloup period. Bacteriological improvement as defined as eradication of the pretreatment pathogen, ith subsequent appearance of one or more ne pathogenic species susceptible to ceftriaxone. Persistence of the initial pathogen after 48 h of therapy as considered to indicate bacteriological failure. Clinical response as defined as complete resolution of abnormal findings. Clinical improvement as defined as incomplete resolution of abnormal findings or as a relapse during the follo-up period. No apparent response to therapy as considered to indicate clinical failure. Complete blood count, platelet count, serum electrolytes, blood urea nitrogen, creatinine, serum biirubin, alkaline phosphatase, glutamic pyruvic transaminase, glutamic oxaloacetic transaminase, and prothrombin and partial thromboplastin times ere obtained before, during, and after therapy. Specimens ere processed routinely in the bacteriology laboratory of the Veteran's Hospital and identified by standard techniques. Susceptibility of isolated Donloaded from http://aac.asm.org/ on July 22, 218 by guest

14 MASLOW ET AL. pathogens to ceftriaxone as determined by the disk method of Bauer et al. (2) and by the broth dilution method. An 18-h culture of the organism gron in Mueller-Hinton broth as diluted to a final concentration of 15 organisms per ml, and.5-ml amounts ere inoculated into serial tofold dilutions of ceftriaxone to give a final volume of 1. ml. The minimal inhibitory concentration (MI as defined as the loest concentration of antibiotic preventing visible turbidity. The minimal bactericidal concentration (MB as defined as the loest concentration of antibiotic resulting in no bacterial groth after a subculture of.1 ml onto antibiotic-free Mueller-Hinton agar. Blood specimens ere obtained 1 and 12 h after an infusion of ceftriaxone on days 1 and 4 of the study. Serum specimens ere frozen at -2 C. Antibiotic assays ere performed ithin 2 eeks by using a modified agar ell diffusion technique in Mueller- Hinton agar, ith Escherichia coli 146 as the standard. RESULTS Microbiology. Among 2 organisms isolated, 18 ere gram negative, and 2 ere gram positive. Sites of infection included blood (three patients), urinary tract (six patients), respiratory tract (seven patients), biliary tract (three patients), ascitic fluid (one patient) and skin (one patient). The same E. coli biotype as isolated from both the bile and the blood of patient 1. Four patients ere infected ith to different organisms. For 19 organisms (95%), the MIC of ceftriaxone as 12.5,ug/ml or less. The MBC of ceftriaxone for the majority of strains as equal to or ithin to tube dilutions of the MIC. The MBC of ceftriaxone for one Serratia marcescens isolate as three dilutions greater than the MIC. Clinical and laboratory data from the 18 patients are presented in Table 1. Bacteriological and clinical outcome. Tentyone infections ere treated ith ceftriaxone, and results of therapy are presented in Table 2. Bacteriological response occurred in 16 of 17 infections (94%) from hich pathogens ere recovered. One patient in this group died of an underlying disease after the infecting organisms ere eradicated. Bacteriological improvement occurred in one patient ith peritonitis resulting from small-boel perforation; E. coli as eradicated, but Bacteroidesfragilis as present after 48 h of therapy. This patient died of Candida albicans peritonitis. Pretreatment pathogens ere not recovered from four patients. Clinical response occurred in 1%o of these infections during ceftriaxone therapy. Specific infections. (i) Bacteremia. E. coli as isolated from the blood of to patients, and Proteus mirabilis as isolated from the blood of another. Bacteremia as eradicated by ceftriaxone in each instance. One patient had the same organism recovered from both bile and blood. ANTIMICROB. AGENTS CHEMOTHER. Blood cultures obtained 24 to 48 h after therapy ere sterile in all cases. One patient died after blood cultures had become negative. (Hi) Urinary tract infection. Six patients ere treated for urinary tract infections, and all shoed a bacteriological response. To individuals ere infected ith to different gramnegative organisms. Enterococcal infection developed in one patient during treatment and in another patient ithin 1 eek after completion of therapy. (iii) Respiratory infection. Six patients had pneumonia, and one patient had purulent tracheobronchitis. Sputum as obtained from four patients by nasotracheal suctioning, and expectorated sputum as evaluated in the remaining three patients. Species of knon virulence ere considered invasive if they predominated in purulent specimens and if correlation existed beteen Gram stain and clinical findings. Pathogens ere recovered from five patients, all of hom shoed a bacteriological response. Patient 15 died of hepatic failure after a bacteriological response as demonstrated. The remaining to patients had infiltrates, fever, leukocytosis, and organisms seen on Gram stain (gram-positive diplococci in patient 1 and gram-negative coccobacilli in patient 16); hoever, only normal flora ere isolated from sputum cultures. Both patients shoed clinical and radiographic resolution of their infections. (iv) Bilary tract infection. Three patients had acute cholecystitis, and all ere cured by surgery and ceftriaxone. Patient 1 had a perforated gallbladder, and E. coli as isolated from both bile and blood. Sterilization of bile as documented 2 days after surgery. The bile concentration of ceftriaxone 14 h after discontinuation of therapy as 1.5,ug/ml. Patient 18 had E. coli bacteremia and underent surgery on day 9 of ceftriaxone therapy. The concentration of ceftriaxone in the bile as 1,6,ug/ml 5 h after a dose, and cultures ere sterile. Patient 8 had right upper quadrant pain, fever, leukocytosis, and an abnormal ultrasound examination. Cholecystectomy as performed on day 2 of antibiotic therapy, at hich time bile cultures ere sterile. There as a fall in temperature and peripheral leukocyte count after institution of ceftriaxone treatment and before surgery as carried out. (v) Skin infection. Patient 1 as treated ith ceftriaxone for an infected diabetic foot ulcer ith cellulitis. S. marcescens as isolated from the ulcer, and P. mirabilis as recovered from the blood. The patient ultimately required amputation, after a bacteriological response as demonstrated. (vi) Peritoneal infection. Patient 14, ith portal hypertension and ascites, developed E. coli peritonitis. Paracentesis after 2 days of therapy ith Donloaded from http://aac.asm.org/ on July 22, 218 by guest

VOL. 22, 1982 CEFTRIAXONE TREATMENT OF BACTERIAL INFECTIONS 15 C. -j I-- 1-A 1- " --.b. "JI-A % o-j asa.o tco CP P P a Ca C C:P _. V o Pm o b. r :- :- :- n -o C. l). _. P-1 cl ce % ~o ) CA ~~~~~~~~5 1 r. ~~ae(','' 9, 4 C 't i P t B- - S an z il - CqmeRb v a a e P op 8 ~O ~- O OA ~~Ag~j ~A a Ws, t. ).A -_- 1" _ O CD CD -S ta4 o O. -.-t~ a Z, 14Z S OSOS a aa\ t\ - t' t J Z D o.1 1 Oit ooao ~ ~ ~ ~ ~ - O-.~-~ ~~~~~ -O 8 )r _ <r V U). to l<.-q o m o - r ni.. co m P, 1 to Donloaded from http://aac.asm.org/ o co co c Un ce O )UO UO POPPPO CZ C z z = 7 C r ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ c r U)U)- U)U) U) U) U) Z Z ZZ 'TIzZZ ZZ Z zz ~~ ~ ~ ~ ~ ~~.. 7r = s OC r z I o m. _ CO g- n M. a -' ) C. la., ca. (D :. 5 co on July 22, 218 by guest Cro Ml ~~E. (A1 CD ; O C - :s CC 5

16 MASLOW ET AL. TABLE 2. Outcome of infections treated ith ceftriaxone No. No. of No. of No. of Site Siteofnfecion infection of organisms bacteriociia infec- isolateda logical responses tions responsesrepns Blood Urine 6 8 8 6 Respiratory tract 7 6 6 7 Bile 1 1 Skin 1 1 1 1 Peritoneum 1 1 a Three patients had to organisms recovered from the same site, and four patients had no pathogens isolated. ceftriaxone yielded no E. coli groth, but infection ith B. fragilis and C. albicans as documented. A small-boel perforation as found during surgery, and treatment as changed to clindamycin, ampicillin, amikacin, and amphotericin B. The patient died of septic shock, hepatic failure, and C. albicans peritonitis. Ceftriaxone concentrations in serum and other body fluids. Ceftriaxone serum concentrations ere determined on days 1 and 4 of therapy (Table 1). Concentrations in bile and ascitic fluid ere also measured. Serum concentrations 1 h after a dose ere 2 to 15 jig/ml (mean, 68.4,ug/ ml) on day 1 of treatment and 5 to 18,ug/ml (mean, 12.2,ug/ml) on day 4 of treatment. Trough concentrations ere <6 to 1,ug/ml (mean, 7.8 jig/ml) on day 1 of treatment and <6 to 1,ug/ml (mean, 48.7 p.g/ml) on day 4 of treatment. The highest trough concentration (1,ug/ml) as obtained from a patient ith moderate renal insufficiency (creatinine, 4. mg/ 1 ml). The ascitic fluid concentration of ceftriaxone in a patient ith peritonitis as 16,ug/ml 1 h after a dose. Bile concentrations of ceftriaxone ere measured in to patients. In patient 1, aspiration of bile from the T-tube 14 h after the final dose yielded a concentration of 1.5,ug/ml. Patient 18 had a bile concentration of 1,6,ug/ ml 5 h after a dose of 1 g on day 9 of therapy. Superinfection. To patients developed infections due to enterococci during or after ceftriaxone therapy. Patient 12 required a cystotomy and permanent catheter drainage for treatment of urethral strictures, and an enterococcal infection developed on day 5 of therapy. Patient 4 as successfully treated for a mixed E. coli and P. mirabilis urinary tract infection. Three days after completion of therapy, enterococci ere cultured from the urine at a time hen the patient as asymptomatic. Toxicity. Local tolerance to intravenous injection as excellent. Transient neutropenia as ANTIMICROB. AGENTS CHEMOTHER. noted in one patient (patient 2) hose leukocyte count decreased to,1/mm after 7 days of therapy. One day after ceftriaxone therapy as discontinued, the leukocyte count as 6,5/ mm. Patient 9 developed fever after 7 days of treatment. After ceftriaxone therapy as discontinued, the serum alkaline phosphatase and transaminase levels became elevated. Quinidine therapy as then discontinued, and both fever and hepatic abnormalities resolved. DISCUSSION Pharmacokinetic studies (7, 8) have demonstrated that the half-life of ceftriaxone is approximately 6 to 8 h. This unusually long half-life is attributed to a significant nonrenal mechanism of excretion and distribution, presumably hepatobiliary. With a dose of 1 g every 12 h, serum, biliary, and ascitic fluid concentrations of ceftriaxone ere significantly in excess of the MICs and MBCs of this antibiotic for individual isolates. Ceftriaxone has a broad spectrum of activity, especially against the Enterobacteriaceae and non-enterococcal streptococci. It has greater in vitro activity against non-enterococcal streptococci (particularly Streptococcus pneumoniae) than moxalactam (1, 6, 9, 1) and greater activity against all Proteus species than either cefotaxime or moxalactam (4, 9). Its enhanced activity against aerobic pathogens and unusually long half-life give ceftriaxone a potential advantage over other third-generation cephalosporins in the treatment of certain infections. Ceftriaxone may be especially useful in hospitalized patients, in hom less frequent dosing is desirable, and in the parenteral therapy of outpatients. Exceptions to the broad spectrum of ceftriaxone are Bacteroides fragilis, enterococci, methicillin-resistant staphylococci, and some Pseudomonas species. Persistence of B. fragilis in the peritoneal cavity of one patient confirmed in vitro data shoing ceftriaxone to be less active than cefoxitin (9), moxalactam, or cefotaxime (11) against members of the B. fragilis group. This drug should probably not be used as the sole therapy for serious intraabdominal infections in hich B. fragilis may play a predominant role. To patients in this study developed infections ith enterococci, one during and one after therapy ith ceftriaxone. Thus, enterococci should be suspected hen superinfections occur, especially superinfections of the urinary tract. Hinkle and Bodey (5) shoed that 98% of their penicillin-resistant Staphylococcus aureus species ere inhibited by 6.25,ug of ceftriaxone per ml. Other investigators (11) have shon ceftriaxone to be comparable to cefotaxime Donloaded from http://aac.asm.org/ on July 22, 218 by guest

VOL. 22, 1982 against this organism and superior to moxalactam. Only one patient in this study as infected ith S. aureus. Although the MIC of ceftriaxone for this organism as 12.5,ug/ml, serum concentrations several times greater than the MIC ere achieved. The patient shoed complete bacteriological and clinical responses ithin 1 eek. In summary, this study suggests that ceftriaxone is an effective and safe cephalosporin for the treatment of urinary, respiratory, and biliary tract infections and bacteremia not due to endocarditis. Because of its long half-life and increased potency against certain pathogens, it can be administered in a loer dose and at longer intervals than currently available cephalosporins. ACKNOWLEDGMENT This study as supported by Hoffmann-La Roche Inc., Nutley, N.J. LITERATURE CITED 1. Angehrn, P., P. J. Probst, R. Relner, and R. L. Then. 198. Ro 1-994, a long-acting broad-spectrum cephalosporin: in vitro and in vivo studies. Antimicrob. Agents Chemother. 18:91-921. 2. Bauer, A., W. Kirby, J. Sherris, and M. Turck. 1966. Antibiotic susceptibility testing by a standardized single disc method. Am. J. Clin. Pathol. 45:49-496.. Beskid, G., J. G. Christenson, R. Cleeland, W. DeLorenzo, CEFTRIAXONE TREATMENT OF BACTERIAL INFECTIONS 17 and P. W. Tron. 1981. In vivo activity of ceftriaxone (Ro 1-994), a ne broad-spectrum semisynthetic cephalosporin. Antimicrob. Agents Chemother. 2:159-167. 4. Hall, M. J., D. Westmacott, and P. Wong-Kal-In. 1981. Comparative in vitro activity and mode of action of ceftriaxone (Ro 1-994), a ne highly potent cephalosporin. J. Antimicrob. Chemother. 8:19-2. 5. Hinkle, A. M., and G. P. Bodey. 198. In vitro evaluation of Ro 1-994. Antimicrob. Agents Chemother. 18:574-578. 6. Neu, H. C., N. Asapokee, K. P. Fu, and P. Asapokee. 1979. Antibacterial activity of a ne 1-oxa cephalosporin compared ith that of other,b-lactam compounds. Antimicrob. Agents Chemother. 16:141-149. 7. Patel, I. H., S. Chen, M. Parsonnet, M. R. Hackman, M. A. Brooks, J. Konikoff, and S. A. Kaplan. 1981. Pharmacokinetics of ceftriaxone in humans. Antimicrob. Agents Chemother. 2:64-641. 8. Seddon, M., R. Wise, A. P. GUflett, and R. Livingston. 198. Pharmacokinetics of Ro 1-994, a broad-spectrum cephalosporin. Antimicrob. Agents Chemother. 18:24-242. 9. Shannon, K., A. King, C. Warren, and I. Phillips. 198. In vitro antibacterial activity and susceptibility of the cephalosporin Ro 1-994 to beta-lactamases. Antimicrob. Agents Chemother. 18:292-298. 1. Trager, G. M., G. W. White, V. M. Zimelis, and A. P. Panalker. 1979. LY-12795: a novel beta-lactam antibiotic ith unusual antibacterial activity. Antimicrob. Agents Chemother. 16:297-. 11. Wise, R., A. P. Gillett, J. M. Andres, and K. A. Bedford. 198. Ro 1-994: a cephalosporin ith a high degree of activity and broad antibacterial activity: an in vitro comparative study. J. Antimicrob. Chemother. 6:595-6. on Donloaded from http://aac.asm.org/ July 22, 218 by guest