Clinical evaluation of cefotaxime for therapy of lower respiratory tract infections

Cefotaxime versus ampicillin, methicillin and netilmicin in combination for treatment of febrile episodes in patients with haematologic malignancy

A prospective, randomized trial comparing treatment of 61 febrile episodes with cefotaxime (CTX) versus a combination of ampicillin, methicillin, and netilmicin (AMN) was carried out in 58 patients with leukaemia or malignant lymphoma, of whom 28 had a granulocyte count of less than or equal to 500 X 10(6)/l. The overall response frequency was 63% for CTX against 49% for the AMN combination, the latter figure being lower than generally reported in the literature. The difference was not statistically significant. In 21 episodes pathogens were isolated, 16 of them from the blood. All isolated bacteria but one, a strain of Bacteroides fragilis, were fully sensitive to at least one of the three antibiotics in the combination, and all but one, a strain of Listeria monocytogenes, were fully sensitive to CTX. These results indicate that CTX seems to be a promising alternative as monotherapy for empiric treatment of febrile episodes in patients with haematologic malignancies. Further investigations will, however, be required before completely rational choices between mono and combination therapy of febrile episodes in immunosuppressed patients can be made.

A study of the etiologies and treatment of nosocomial pneumonia in a community-based teaching hospital

OBJECTIVE

To compare the frequency of the pathogens of nosocomial pneumonia in a community-based teaching hospital to the frequencies previously published, and to evaluate recommendations for the therapy of nosocomial pneumonia in this setting.

DESIGN

Retrospective review of prospectively acquired data accrued during 9 randomized single-blinded and 4 single-agent investigational antibiotic studies for the therapy of pneumonia in hospitalized patients between 1981 and 1989.

SETTING

The study was performed at a university affiliated, community-based teaching Department of Veterans Affairs Medical Center.

PATIENTS

Patients were hospitalized on the acute medical/surgical and intermediate medicine wards. Informed consent was obtained prior to enrolling patients into the respective antimicrobial studies. Pneumonia was documented radiographically and clinically for each patient.

RESULTS

Two hundred thirty-one episodes of nosocomial pneumonia were treated. Overall, 51% of pneumonias were caused by Streptococcus pneumoniae or Hemophilus influenzae with or without other organisms that were not gram-negative bacilli. Gram-negative bacilli, with or without other organisms, accounted for only 26% of all nosocomial pneumonias. Overall, monotherapy with a cephalosporin (usually a broad-spectrum agent) was equally efficacious compared with combination therapy (87% versus 81%, respectively). Cure rates for nosocomial pneumonias from gram-negative bacilli treated with these 2 therapies also were similar (70% versus 60%, respectively).

CONCLUSIONS

In nontertiary care settings, gram-negative bacilli may cause fewer episodes of nosocomial pneumonia (26% in this study) than noted by previously published reports, which indicated that these organisms account for 50% of nosocomial pneumonias. Further, S pneumoniae and H influenzae may account etiologically for many of these nosocomial pneumonias. Monotherapy with an extended-spectrum cephalosporin may be more appropriate than combined treatment with a beta-lactam and an aminoglycoside in a nontertiary care setting, thereby reducing potential toxicity in an older, hospitalized patient population.

[Ceftazidime versus cefotaxime in the therapy of severe infections in intensive care patients]

In a randomized controlled, clinical study the efficacy of ceftazidime at a dosage of 2 g b. i. d. was compared to that of cefotaxime at a dosage of 2 g t. i. d. or more in the treatment of pneumonia or peritonitis in intensive care patients. 61 of 67 assessable cases were evaluable. In the ceftazidime group ten out of 11 patients with pneumonia and 17 out of 20 with peritonitis showed a clinical success. In the cefotaxime group 15 out of 19 patients with pneumonia and eight out of 11 with peritonitis were clinically cured or improved. With ceftazidime an overall success was achieved in 87% of the patients (27 out of 31) and with cefotaxime in 77% of the patients (23 out of 30). Two patients in the cefotaxime group developed a reinfection. Five of the patients treated with cefotaxime and four of those treated with ceftazidime were therapeutical failures. Escherichia coli, Pseudomonas, Klebsiella, Enterobacter and Proteus species as well as Staphylococcus aureus and enterococci were the most frequent organisms isolated prior to therapy. Following ceftazidime therapy 30 of the 32 gram-negative species were eliminated, whereas in the cefotaxime group the number of gram-negative species isolated was reduced from 28 to ten. Gram-positive species isolated in ten cases prior to therapy, were still present in seven cases after ceftazidime therapy and the number of gram-positive organisms was reduced from 19 to ten following treatment with cefotaxime. In one patient therapy with ceftazidime was stopped due to urticaria. Reversible leukopenia was observed in a patient treated with ceftazidime and a cholestatic reaction in a patient treated with cefotaxime. In both groups a slight elevation of transaminases was seen.

Treatment of respiratory tract infections with cephalosporin antibiotics

Infections of the respiratory tract are among the most common causes for antibiotic prescribing. Their diagnosis within the community is generally limited to clinical criteria, and microbiological information is frequently lacking. Hospitalised patients with respiratory tract infections are more likely to undergo diagnostic sampling, but difficulties remain in reliably defining a microbial aetiology, thereby providing a confident basis for antibiotic selection. In considering the role of the cephalosporins in the treatment of respiratory tract infections, over 500 published articles have been reviewed. The pharmacokinetic considerations are discussed and the limitations of existing methodology are emphasised. Individual agents are reviewed by site of sepsis and conclusions are drawn from both comparative and non-comparative studies and in relation to currently recommended regimens. Although oral cephalosporins are widely used to treat upper respiratory tract infections, none is considered ideal, especially where Haemophilus influenzae is pathogenic. In the case of lower respiratory tract infections the beta-lactamase stable parenteral cephalosporins have become widely used to treat pneumonia in hospitalised patients, especially where Gram-negative enteric bacilli are of aetiological importance. However, the lack of activity of these drugs against Legionella spp., Mycoplasma pneumoniae and Coxiella burnetii must be emphasised. Another area of increasing use is in the treatment of infective exacerbations in patients suffering from cystic fibrosis of the lungs where Pseudomonas aeruginosa is pathogenic; ceftazidime in particular has proved a useful alternative to earlier antipseudomonal penicillin antibiotics.

Comparison of ceftazidime with cefamandole for therapy of community-acquired pneumonia

Ceftazidime and cefamandole were compared in the treatment of pneumonia. The median MIC of ceftazidime for all Streptococcus pneumoniae (n = 17) and Haemophilus influenzae (n = 10) isolates was 0.125 microgram/ml. All other isolates were inhibited by less than 0.5 microgram of ceftazidime per ml, with the exception of a group B streptococcus (MIC = 4 micrograms/ml). Satisfactory clinical responses were observed in 91% (20 of 22) of cefamandole-treated patients and 85% (17 of 20) of ceftazidime-treated patients.

Cefotaxime: efficacy and tolerance in lower respiratory tract infections caused by gram-positive cocci

Cefotaxime is an effective antibiotic in lower respiratory tract infection caused by streptococci and staphylococci. There is a limited tendency to superinfections with Pseudomonas aeruginosa (1.5%) and there is a low incidence of side-effects. It is questionable whether there is really an urgent need for cefotaxime in gram-positive lower respiratory tract infections.

Gram-positive superinfections following beta-lactam chemotherapy: the significance of the enterococcus

The recent literature was reviewed with regard to the risks of superinfection following beta-lactam chemotherapy. The summary publications for the pseudomonas-active penicillins (azlocillin, carbenicillin, mezlocillin, piperacillin and ticarcillin), cefoperazone, cefotaxime, ceftazidime, imipenem and moxalactam show marked variations. Moxalactam was most likely to produce both gram-negative (5-38%) and enterococcal (2.2-12%) superinfections. Ceftazidime or moxalactam therapy was more often associated with anaerobic superinfections, usually by Clostridium spp., than the other beta-lactams. Comparable and lower incidences of superinfections were cited for cefoperazone, ceftazidime, mezlocillin and imipenem. The most common pathogens for the above drugs were the fungi (Candida spp.), Pseudomonas spp. and some beta-lactamase-producing Enterobacteriaceae. Staphylococcal, Escherichia coli and Klebsiella spp. secondary infections were more common in patients receiving the newer penicillins. Cefotaxime had a very low incidence of superinfections (1.1%), especially caused by gram-positive organisms such as enterococci. The reasons for this favorable feature seem to be: excellent inhibitory activity and beta-lactamase stability against a wide variety of bacterial pathogens, synergistic interactions of cefotaxime and its desacetyl metabolite, enhanced anti-enterococcal activity of cefotaxime in the presence of a human serum factor and interactions of cefotaxime and desacetyl cefotaxime to suppress the development of antimicrobial resistance. The most common superinfections following cefotaxime treatment were with Pseudomonas spp., Enterobacter spp. and fungi. Cefotaxime appears to possess physical-chemical characteristics that react favorably with bacteria and the host to minimize gram-positive superinfections, especially with most enteric Streptococcus spp. (Streptococcus faecalis and Streptococcus faecium).

Clinical experience with cefotaxime for the therapy of bacteremias due to gram-positive organisms

Fifty-five patients with gram-positive bacteremias were treated with cefotaxime after enrollment in comparative and non-comparative study protocols. Forty-nine of these 55 patients were evaluable and followed for their response to therapy and adverse effects. Most patients were white males 50 years of age or older (69%); 45% had two or more serious underlying diseases. Pneumonias caused 59% of these bacteremias, which were etiologically due to Streptococcus pneumoniae (22 episodes), Staphylococcus aureus (15), coagulase-negative staphylococci (3) and other streptococci (12). Overall, 90% of bacteremias were cured with cefotaxime therapy. Among five treatment failures were included three deaths, one due to cefotaxime-associated pseudomembranous colitis, one caused by a bacteremic superinfection due to Pseudomonas aeruginosa and one due to a progressive pneumonia despite therapy. Adverse effects of therapy were infrequent and noteworthy for only one patient with questionable nephrotoxicity and a lack of cefotaxime-associated coagulopathy.

Respiratory superinfections after the use of third-generation cephem antibiotics

This paper is a report on our studies on superinfections in respiratory tract infections treated during the years 1981-1984. The isolated strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Streptococcus faecium and glucose non-fermentative gram-negative rods such as Pseudomonas aeruginosa were resistant to third-generation cephem antibiotics. These organisms proved to be widely distributed in hospitals and were frequently isolated from the sputum, excised lung and cardiac blood. The colonization of the sputum by bacteria in respiratory tract infections before, during and after treatment with third-generation cephem antibiotics revealed a tendency for these organisms to appear after treatment. Among the gram-positive cocci, S. faecium was most resistant to these antibiotics, followed by S. faecalis, S. epidermidis and S. aureus in that order. The incidence of resistant isolates in 1984 exceeded that in 1983, suggesting an annual increase in resistant bacteria.

Use of ceftazidime in the therapy of serious infections, including those due to multiresistant organisms

Ceftazidime was administered intravenously or intramuscularly or both in doses of 1 to 6 g per day to 33 patients with serious gram-negative bacillary infections (12 pulmonary, 10 urinary tract, 4 soft tissue, 4 intraabdominal, and 3 miscellaneous infections). Twenty-one patients were septicemic. We identified 20 isolates of members of the family Enterobacteriaceae and 13 isolates of Pseudomonas aeruginosa. Seventeen patients had failed to respond to previous antimicrobial therapy. A total of 23 patients were clinically cured, 7 patients improved, and 3 patients failed to respond to therapy. The selection or emergence of resistant organisms during treatment (mostly Candida spp., Staphylococcus aureus, and enterococci) was noted in 11 patients. Toxicity was minimal (reversible mild liver function abnormalities and eosinophilia). The results of this study suggest that ceftazidime is an effective and well-tolerated new cephalosporin for the therapy of serious infections due to susceptible gram-negative organisms.

Serum bactericidal activity of ceftazidime and cefoperazone alone or in combination with amikacin against Pseudomonas aeruginosa and Klebsiella pneumoniae

Sera of volunteers receiving ceftazidime (2 g) or amikacin (500 mg), alone or in combination, or cefoperazone (2, 4, or 6 g) or cefoperazone (2 g) with amikacin (500 mg) were evaluated for bactericidal activity against Klebsiella pneumoniae and Pseudomonas aeruginosa. Serum bactericidal activities were similar for ceftazidime and ceftazidime plus amikacin, but were definitely lower for amikacin alone. Against P. aeruginosa, a 6-g dose of cefoperazone resulted in a higher frequency of peak serum bactericidal activities greater than or equal to 1:8 than a 2-g dose of cefoperazone plus amikacin. Killing studies, performed in 1:8 diluted serum, demonstrated a higher killing rate for cefoperazone plus amikacin than for a 6-g dose of cefoperazone, the more resistant P. aeruginosa excepted. Emergence of resistance was found with a 2-g dose of cefoperazone for K. pneumoniae and with a 6-g dose of cefoperazone for P. aeruginosa, but not with cefoperazone plus amikacin.

Cefotaxime. A review of its antibacterial activity, pharmacological properties and therapeutic use

SYNOPSIS

Cefotaxime is a new 'third generation' semisynthetic cephalosporin administered intravenously or intramuscularly. It has a broad spectrum of activity against Gram-positive and Gram-negative aerobic and anaerobic bacteria, and is generally more active against Gram-negative bacteria than the 'first' and 'second generation' cephalosporins. Although cefotaxime has some activity against Pseudomonas aeruginosa, on the basis of present evidence it cannot be recommended as sole antibiotic therapy for pseudomonal infections. However, cefotaxime has been effective in treating infections due to other 'difficult' organisms, such as multidrug-resistant Enterobacteriaceae. Like other cephalosporins, cefotaxime is effective in treating patients with complicated urinary tract and lower respiratory tract infections, particularly pneumonia caused by Gram-negative bacilli. High response rates have also been achieved in patients with Gram-negative bacteraemia. Although favourable clinical results have been obtained in patients with infections caused by mixed aerobic/anaerobic organisms (such as peritonitis or soft tissue infections), the relatively low in vitro activity of cefotaxime against Bacteroides fragilis may restrict its usage in situations where this organism is the suspected or proven pathogen. In preliminary studies, males and females treated with a single intramuscular dose of cefotaxime for uncomplicated gonorrhoea caused by penicillinase-producing strains of Neisseria gonorrhoeae responded very favourably. Encouraging results have also been reported in open studies in children including neonates, treated with cefotaxime for meningitis and various other serious infections. In some situations, cefotaxime has been given in combination with another antibiotic such as an aminoglycoside, but the merits of such a combination have not been clearly established. Whether cefotaxime alone is appropriate therapy for conditions previously treated with aminoglycosides (other than pseudomonal infections) also needs additional clarification, but if established as equally effective in such conditions cefotaxime offers potentially important clinical and practical advantages in its apparent lack of serious adverse effects and freedom from the need to undertake drug plasma concentration monitoring.