Antibacterial activity of a new parenteral cephalosporin--HR 756: comparison with cefamandole and ceforanide

Ceforanide. A review of its antibacterial activity, pharmacokinetic properties and clinical efficacy

Ceforanide is a 'second generation' cephalosporin administered intravenously or intramuscularly. It is similar to cefamandole and cefonicid in its in vitro superiority to 'first generation' cephalosporins against several species of Enterobacteriaceae as well as its activity against Haemophilus influenzae, including beta-lactamase-producing strains. Its activity against Staphylococcus aureus is less than that of cefamandole, cefuroxime and first generation cephalosporins. The in vitro activity against Neisseria gonorrhoeae is excellent. Pseudomonas, Acinetobacter and Serratia species, and Bacteroides fragilis are resistant, as are many strains of Proteus and Providencia species. The elimination half-life is relatively long, although shorter than that of cefonicid, and in most clinical trials ceforanide has been administered twice daily. It appeared to be comparable in therapeutic efficacy to procaine penicillin and cephazolin in the treatment of patients with community-acquired pneumonia, to cephazolin in the treatment of skin and soft tissue infections due to S. aureus or beta-haemolytic streptococci and to cefapirin in S. aureus endocarditis in parenteral drug abusers. Also, it was comparable in efficacy to cephalothin in the prophylaxis of infection in patients undergoing open heart surgery or vaginal hysterectomy, and to cephazolin in patients undergoing cholecystectomy. Thus, ceforanide is an alternative to first and certain other second generation cephalosporins in several important therapeutic and prophylactic situations. It has no advantage over other cephalosporins with regard to spectrum of antibacterial activity, but has a longer half-life than other second generation cephalosporins, except cefonicid, and can be administered according to a twice daily dosage schedule.

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.

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.

Ceforanide: antibacterial activity, pharmacology, and clinical efficacy

Ceforanide is a new cephalosporin with a longer elimination half-life than any currently available cephalosporin. Its activity is very similar to that of cefamandole, a second-generation cephalosporin, except that ceforanide is less active against most gram-positive organisms. Many coliforms, including Escherichia coli, Klebsiella, Enterobacter, and Proteus, are susceptible to ceforanide, as are most strains of Salmonella, Shigella, Hemophilus, Citrobacter and Arizona species. However, most strains of Serratia marcescens and all Pseudomonas aeruginosa are resistant to this compound. Peak serum concentrations in excess of 100 micrograms/ml are achieved after a 1 g intravenous dose. The elimination half-life of ceforanide is about 3 hrs in patients with normal renal function; this allows twice daily dosing for the majority of patients. As renal excretion amounts for 85-90% of drug elimination, the serum half-life increases to approximately 20 hours in anuric patients. Tissue penetration studies demonstrate inhibitory concentrations in cardiac tissue, bone, and joint fluid. Minor adverse effects have been reported after large doses of ceforanide. Clinical trials indicate that ceforanide is effective in the treatment of skin and soft tissue, pulmonary and urinary tract infections, bone and joint infections, and endocarditis. Ceforanide also has been shown to be as effective as cephalothin or cephaloridine when given prophylactically for vaginal hysterectomy.

Mechanism of action, antimicrobial activity, pharmacology, adverse effects, and clinical efficacy of cefotaxime

Cefotaxime sodium, a parenteral cephalosporin antibiotic, exerts its bactericidal action through inhibition of bacterial cell wall synthesis. Chemical structure modifications have enabled this compound to be resistant to the action of Richmond I, III, IV, and V beta-lactamase enzymes. Excellent activity against many gram-negative bacilli, especially Enterobacteriaceae, has been demonstrated. Antipseudomonal activity is generally poor, however. Activity against gram-positive cocci, with the notable exception of Streptococcus fecalis, is adequate. Anaerobic activity is variable, particularly against Clostridia and Bacteroides species. Acute, subacute, and chronic toxicity studies in animals were generally unremarkable. No mutagenic effects or reproductive toxicity have been noted in animals. In man, cefotaxime is desacetylated to a microbiologically active metabolite. Urinary excretion is approximately 50-60% and 15-20% of a dose for the parent compound and desacetyl metabolite, respectively. The elimination half-life of cefotaxime is about one hour, with the total body clearance being approximately twice that of the renal clearance. Severe renal dysfunction causes a prolongation of the elimination half-life of cefotaxime and particularly desacetyl cefotaxime. A relatively low degree of protein binding in part attributes to a wide bodily distribution of cefotaxime. Cefotaxime is effective in a variety of infectious processes caused by susceptible organisms. Local reactions at the injection site and hypersensitivity phenomena are the most common adverse effects. Comparative trials attesting to cefotaxime's clinical utility over other parenteral cephalosporins or amino-glycosides are very limited. Based on the available evidence, cefotaxime should be most useful in combating serious gram-negative infections, because of its excellent activity against most of these organisms and its low toxicity profile.

Cefoxitin therapy in aerobic, anaerobic, and mixed aerobic-anaerobic infections

Cefoxitin, a new beta-lactamase-resistant cephamycin, was evaluated in 66 patients for clinical and bacteriological efficacy, serum levels, tolerance, and toxicity. Seventeen patients had soft tissue infections, 14 had pleuropulmonary infections, 14 had intraabdominal infections, 13 had pelvic infections, and 8 had urinary tract infections. Among the 66 patients, 62 were cured and 4 could not be evaluated. Twelve patients had hospital-acquired infections, 31 had underlying disease, and 45 required a surgical procedure. Isolates included 116 aerobic and 72 anaerobic bacteria. Cefoxitin was more active than cephalothin against facultative and obligate anaerobic gram-negative organisms isolated from these patients. Mean peak cefoxitin levels in sera were 52 micrograms/ml after a 2-g infusion and 30 micrograms/ml after a 1-g infusion. Phlebitis occurred in two patients, eosinophilia in one, rash in two, vasculitis in one, and transient rises in SGOT and SGPT in two. Cefoxitin appears to be a safe and effective drug for the treatment of many aerobic, anaerobic, and mixed aerobic-anaerobic infections.

Cefotaxime therapy of serious infections with multiresistant gram-negative bacilli

33 patients with serious gram-negative bacillary infections were treated with cefotaxime. In patients with normal renal function the dose varied between 1.5 to 4 g/day. 17 patients had urinary tract infections, 5 respiratory tract infections, 1 combined urinary tract infection and respiratory tract infection, and 10 miscellaneous infections. 16 patients had septicemia. 25 infections were due to pathogens resistant in vitro to ampicillin, cephalothin, gentamicin and/or tobramycin. 15 infections had failed to respond to ampicillin, cefazolin, gentamicin or tobramycin therapy. 32/33 patients responded favourably to cefotaxime (cure or improvement) but 4 patients developed superinfection with cefotaxime-resistant bacteria. No evidence of nephrotoxicity was observed except for a transient moderate rise in creatinine in one patient.

Cefotaxime therapy of serious bacterial infection in adults

We evaluated the efficacy, safety, and tolerance of cefotaxime in 35 adults (25 with pleuropulmonary infections, 7 with genitourinary tract infections, and 3 with soft tissue infections). Of these 35 patients, 18 (51.4%) were seriously or critically ill. In vitro susceptibility testing revealed that 90.4% of the pathogens isolated were susceptible to cefotaxime (minimal inhibitory concentration, less than 8 micrograms/ml), 4.8% were intermediately susceptible (minimal inhibitory concentration, 8 to 32 micrograms/ml), and 4.8% were resistant (minimal inhibitory concentration, greater than 32 micrograms/ml). A total of 34 of the 35 patients (97%) were clinically and bacteriologically cured of their infections. Adverse reactions occurred in two patients, but these reactions did not require interruption of therapy.

Clinical evaluation of cefotaxime for therapy of lower respiratory tract infections

A clinical trial was designed to evaluate the efficacy and safety of cefotaxime, a new semisynthetic, broad-spectrum cephalosporin, in the therapy of community-and hospital-acquired pneumonias. Thirty-nine males (mean age, 65 years) were treated for 41 episodes of pneumonia. Only five patient did not have a serious underlying disease; 15 had two or more significant disorders. Sixty-six percent of these pneumonias were due to Streptococcus pneumoniae or Haemophilus influenzae. The minimal inhibitory concentrations for all bacterial isolates ranged from 0.008 to 4 micrograms/ml. Peak serum cefotaxime levels during therapy ranged from 12 to 124 micrograms/ml 1 h after a 1-g dose. Satisfactory bacteriological and clinical responses were observed in 85% of the cases. Four episodes of pulmonary superinfections due to cefotaxime-resistant gram-negative bacilli were noted, each in a patient being mechanically ventilated. Pseudomonas was involved in each of these superinfections, and three were fatal. No serious toxicity or adverse reaction to cefotaxime was seen. The results of this study suggest that cefotaxime is an affective and well-tolerated new cephalosporin antimicrobial agent for the therapy of pneumonia due to susceptible organisms.

Clinical efficacy of cefotaxime in serious infections

Thirty-five patients underwent 38 treatment courses with cefotaxime. Documented infections included 11 bacteremias, 7 cases of nosocomial pneumonia, 6 surgical wound infections, 3 bone infections, 1 biliary infection, and 1 urinary tract infection. Granulocytopenic patients with fever received 15 courses of empiric cefotaxime therapy alone; in 8 courses, no definite site of infection or pathogen was isolated. Broad-spectrum antibiotics had been administered to 23 patients before cefotaxime. Thirty-seven bacterial pathogens were isolated from 25 patients. Three such pathogens were resistant to cefotaxime and required alternative therapies. Pathogenic isolates included 13 Serratia marcescens, 12 Pseudomonas aeruginosa, 4 Escherichia coli, 2 Klebsiella pneumoniae, 2 Providencia stuartii, 1 Enterobacter cloacae, 1 Haemophilus influenzae, 1 Enterococcus, and 1 Staphylococcus aureus. Of the treatment courses, 25 of 38 resulted in a favorable response to cefotaxime, including 9 of 15 in granulocytopenic patients. Superinfection was seen in one patient. The emergence of resistance was documented in another patient. Of 15 patients with multiply resistant pathogens, 12 improved with cefotaxime. Of 12 patients with Pseudomonas aeruginosa, 6 favorably responded. Possible complications of cefotaxime were observed in 14 of 42 treatment courses. Cefotaxime is most useful in treatment of infections due to multiply resistant, gram-negative pathogens other than Pseudomonas aeruginosa.

Serum bactericidal activity of moxalactam and cefotaxime with and without tobramycin against Pseudomonas aeruginosa and Staphylococcus aureus

Serum bactericidal activity was determined against 10 strains each of Pseudomonas aeruginosa and Staphylococcus aureus in serum from volunteers 1 and 6 h after intravenous infusion of cefotaxime, tobramycin, and the combination; or of moxalactam, tobramycin, and the combination. High serum bactericidal activity against P. aeruginosa was found significantly more frequently with moxalactam plus tobramycin than with cefotaxime, moxalactam, and tobramycin alone or with cefotaxime plus tobramycin.

Comparative in vitro activity of first, second and third generation cephalosporins

Minimum inhibitory concentrations (MIC) were determined against 662 recent clinical isolates for eight cephalosporins representing first, second and third generation compounds. All four third-generation cephalosporins tested (cefoperaxone, cefotaxime, ceftazidime and moxalactam) were significantly more active against aerobic gram-negative bacteria than the older compounds (cephalothin, cefamandole, cefoxitin, and cefuroxime). Cefotaxime and moxalactam were most active against Enterobacteriaceae with extremely low MIC-values. Ceftazidime was definitely most active against Pseudomonas aeruginosa with more than 90% of strains inhibited at 4 micro g/ml. MIC-values for cefotaxime against Staphylococcus aureus were for all strains 1-2 micro g/ml, slightly higher for cefoperazone, while the effect of ceftazidime and moxalactam was more limited. All third generation cephalosporins demonstrated efficiency against Streptococcus pyogenes, cefotaxime being most active and moxalactam least active, but were essentially ineffective against Streptococcus faecalis. Moxalactam demonstrated higher activity against Bacteroides fragilis than other second and third generation cephalosporins including cefoxitin. Previous studies have demonstrated a very high activity of all third generation cephalosporins against Haemophilus influenzae and Neisseria gonorrhoeae, including beta-lactamase producing strains.

Comparative in vitro studies of Ro 13-9904, a new cephalosporin derivative

The in vitro activity of Ro 13-9904, a new cephalosporin derivative, was compared with the activities of cephalothin, cefamandole, cefoxitin, cefotaxime, and moxalactam against 591 clinical isolates of gram-negative and gram-positive organisms. The spectra of activity and potency of Ro 13-9904 and cefotaxime were quite similar; they were the most active agents against Enterobacteriaceae, Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae, and Neisseria meningitidis. Moxalactam was only slightly less active against these organisms. Ro 13-9904, cefotaxime, and moxalactam were approximately equal in activity against Pseudomonas aeruginosa; concentrations of 50 to 100 microgram/ml inhibited over 90% of the strains tested. Cefamandole and cephalothin were the most active drugs tested against staphylococci. Moxalactam demonstrated the highest intrinsic activity against Bacteroides fragilis; a concentration of 1.6 microgram/ml inhibited over 50% of the strains. All six of the antibiotics were essentially inactive against group D streptococci. The action of all of the antibiotics was bactericidal, with minimal bactericidal concentrations generally being no more than twofold greater than minimal inhibitory concentrations. The only exception to this was found when large inocula of Staphylococcus aureus were tested. Increased inoculum size generally sharply reduced the activity of Ro 13-9904, cefotaxime, and moxalactam against Enterobacteriaceae and P. aeruginosa.

In vitro antimicrobial activity of cefotaxime, a new cephalosporin

Cefotaxime, a new semisynthetic cephalosporin derivative, showed a broad spectrum of antibacterial activity against clinically isolated strains of gram-positive and gram-negative bacteria. This cephalosporin was slightly less active than cefazolin against Staphylococcus aureus but 4 to 300 times as active as carbenicillin against gram-negative organisms, including Pseudomonas aeruginosa, Pseudomonas cepacia, Enterobacter cloacae, and Serratia marcescens. Cefotaxime was the most active compound against members of the Enterobacteriaceae and 20- to 100-fold more active than cefoxitin against the indole-positive Proteus group. The minimal bactericidal concentrations of the compound were identical to, or two times higher than, the minimal inhibitory concentrations against Escherichia coli and P. aeruginosa and four times higher against S. marcescens. A reduction of inoculum size decreased greatly the minimal inhibitory and bactericidal concentrations of cefotaxime against E. coli P. aeruginosa, and S. marcescens. The antibiotic was very stable to penicillinase and cephalosporinase produced by gram-negative bacteria, including Proteus vulgaris.

Cefotaxime pharmacokinetics following a single intravenous dose to patients with varying renal function

The pharmacokinetics of cefotaxime (HR 756) were investigated in two groups of patients (Groups I and II) with creatinine clearances of greater than or equal to 60 and < 60 ml/min per 1.73 m2 respectively. Each of the 24 patients included in the study received 0.5 g or 1.0 g cefotaxime intravenously as a bolus injection. The decline of serum concentrations was biphasic in all patients, and the data were fitted to the pharmacokinetic two-compartment model. The mean distribution and elimination half-lives of cefotaxime in individuals in Group I were 0.2 and 1.2 hours respectively. In the uremic individuals, the pharmacokinetic parametes did not differ markedly from those in normal subjects, except when renal function was markedly reduced. In severe renal impairment, the elimination half-life increased to 8.3 hours. Cumulative 24-hour urinary excretion accounted for a mean of 59% of the dose in normal individuals, and from 0.3 to 36% of the dose in uremic individuals. Incomplete recovery of intact drug in urine of normal individuals reflects excretion by an extrarenal pathway, possibly as desacetyl cefotaxime. Urine levels were greater than the minimum inhibitory concentrations for susceptible organisms for at least eight hours after dosing in all individuals who produced urine. Because of the relatively small effect of renal impairment on the pharmacokinetics of cefotaxime, dose reduction is necessary only in cases of severe renal impairment.

Comparison of cefoperazone, cefotaxime, and moxalactam (LY127935) against aerobic gram-negative bacilli

This study compares the minimum inhibitory concentrations of cefoperazone, cefotaxime, and moxalactam (LY127935) for 446 aerobic gram-negative bacillary isolates and further compares the minimum inhibitory concentrations of LY127935 and these third-generation cephalosporins with those of thienamycin for Pseudomonas aeruginosa. Each antibiotic at low concentrations inhibited nearly all Enterobacteriaceae tested. Minimum inhibitory concentrations for P. aeruginosa were higher, but for a majority of strains they fell below achievable serum levels. Thienamycin and cefoperazone showed significantly greater antipseudomonal activity than did cefotaxime or LY127935. Cefoxitin-inducible resistance to LY127935 and the two cephalosporins was demonstrated among Enterobacter species but did not occur with thienamycin.