Different doses of cefetamet pivoxil (Ro 15-8075) in the treatment of acute uncomplicated gonococcal urethritis in men

Clinical and economic considerations in the use of third-generation oral cephalosporins

A number of oral third-generation cephalosporins (cefixime, cefetamet pivoxil, ceftibuten and cefpodoxime proxetil) have been widely trialled and are becoming available. In addition, cefdinir may also be marketed. Compared with first- and second-generation agents, the oral third-generation cephalosporins have an improved antibacterial spectrum and reduced minimum inhibitory concentrations against common Gram-negative pathogens. In contrast, with the exception of cefdinir, they are less active against Staphylococcus aureus. They have favourable pharmacokinetic profiles and are generally administered in once- or twice-daily regimens. They are well tolerated, but cefixime has been associated with a particularly high rate of diarrhoea. Possible clinical indications for the use of oral third-generation cephalosporins include upper and lower respiratory, genitourinary and soft-tissue infections and follow-on treatment of severe infections requiring hospitalisation. At present, these drugs offer no particular clinical advantages over standard therapy in most circumstances. However, they may be considered where there is hypersensitivity to penicillins, a high incidence of resistance to first-line therapy in the community, or failure of standard therapy. Further studies are needed to define the efficacy of oral third-generation agents in the prevention of rheumatic fever and as follow-on therapy for severe infections. The oral third-generation cephalosporins are generally more expensive than standard agents, but detailed studies that include extended costs (e.g. treatment of adverse effects, treatment of clinical failure, return visits to physicians) have yet to be reported.

Cefetamet pivoxil in the treatment of uncomplicated gonorrhea

We studied the efficacy and safety of cefetamet pivoxil (CAT), an oral aminothiazolyl cephalosporin, in a series of open, comparative multicenter studies in 207 women (four study centers) with uncomplicated gonorrhea, and summarized and pooled the results with those of earlier open dose-finding trials (360 men; six study centers). We compared single-dose treatment regimen of CAT--over the range of 400-1500 mg--with spectinomycin, thiamphenicol, ampicillin, or amoxicillin plus probenecid. The overall cure rates were 100% in 88 women treated with 1500 mg CAT and in 137 men treated with 1200 or 1500 mg CAT, 98% (114 of 116 men) in those treated with 800 or 1000 mg CAT, and 93% (42 of 45 men) in those treated with 400 or 500 mg CAT; the composite cure rate of the comparators was 97%. The tolerability of CAT (n = 428) compared favorably (1.8% adverse events) with that of the standard drugs (n = 139) (4.3% adverse events). Single-dose treatment with 1500 mg CAT is effective and safe in adults with uncomplicated gonorrhea.

Cefetamet pivoxil. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use

Cefetamet pivoxil is an oral third-generation cephalosporin which is hydrolysed to form the active agent, cefetamet. Cefetamet has excellent in vitro activity against the major respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and group A beta-haemolytic streptococci; it is active against beta-lactamase-producing strains of H. influenzae and M. catarrhalis, but has poor activity against penicillin-resistant S. pneumoniae. Cefetamet has marked activity against Neisseria gonorrhoeae and possesses a broad spectrum of activity against Enterobacteriaceae. Both staphylococci and Pseudomonas spp. are resistant to cefetamet. Cefetamet pivoxil has been investigated in the treatment of both upper and lower community-acquired respiratory tract infections and has demonstrated equivalent efficacy to a number of more established agents, namely cefaclor, amoxicillin and cefixime. In patients with group A beta-haemolytic streptococcal pharyngotonsillitis, a 7-day course of cefetamet pivoxil was as effective as a 10-day course of the standard agent, phenoxymethylpenicillin, in this indication. In complicated urinary tract infections, cefetamet pivoxil showed similar efficacy to cefadroxil, cefaclor and cefuroxime axetil. Cefetamet pivoxil was effective in the treatment of otitis media, pneumonia, pharyngotonsillitis and urinary tract infections in children. Preliminary data indicate that single dose cefetamet pivoxil can effectively eradicate N. gonorrhoeae from both men and women. Cefetamet pivoxil has a tolerability profile similar to that of other oral cephalosporins, with gastrointestinal effects being the most commonly reported adverse events. To date, no symptoms of carnitine deficiency have been reported with cefetamet pivoxil. Cefetamet pivoxil offers effective alternative oral therapy for outpatient treatment of community-acquired respiratory tract infections, with the advantage of improved activity against H. influenzae and increased beta-lactamase stability. However, its use in areas with a high incidence of penicillin-resistant S. pneumoniae is likely to be limited. Cefetamet pivoxil is also effective in the treatment of urinary tract infections, although further trials are required to define any comparative advantages over other oral agents.

Susceptibility testing interpretive criteria and drug stability for cefdinir, cefetamet, and cefpodoxime against Neisseria gonorrhoeae

Cefdinir, cefetamet, and cefpodoxime, three orally administered cephalosporins, were tested against 100 strains of Neisseria gonorrhoeae having various antimicrobial susceptibility patterns. Triplicate testing of each organism strain was performed for all agar dilution and disk diffusion tests. Cefdinir was the most active compound (MIC90) micrograms/ml) especially against gonococci with chromosomal-mediated resistance to penicillin. The recommended susceptible interpretive criteria were as follows: for the 5-micrograms cefdinir disk, > or = 31 mm (MIC correlate, < or = 0.25 microgram/ml); for the 10-micrograms cefetament disk, > or = 29 mm (MIC correlate, < or = 0.5 microgram/ml; for the 30-micrograms cefetamet disk, > or = 31 mm (MIC correlate, < or = 0.5 microgram/ml); and for the 10-micrograms cefpodoxime disk, > or = 29 mm (MIC correlate, < or = 0.5 microgram/ml). No organisms resistant to these new cephalosporins were detected. Cefdinir, cefetamet, and defpodoxime were stable in GC agar medium for at least 21 days when stored at 2 degrees-5 degrees C.

MIC and disk diffusion quality control guidelines for Neisseria gonorrhoeae susceptibility tests of cefdinir, cefetamet, CI-960, fleroxacin, lomefloxacin, and temafloxacin

Cefdinir (FK482), cefetamet (Ro 15-8074), CI-960, fleroxacin, lomefloxacin, and temafloxacin have potent activities against Neisseria gonorrhoeae. They were tested in a multilaboratory study to establish quality control guidelines. Quality control ranges for N. gonorrhoeae ATCC 49226 were determined by using multiple GC agar lots, three disk lots, and a number of test replicates consistent with the M23-T guidelines of the National Committee for Clinical Laboratory Standards. The MIC ranges included 2 to 4 log2 dilution steps. The recommended inhibition zone diameter ranges were generally 7 to 8 mm and included greater than or equal to 91.3% of all recorded study results.

Development of Neisseria gonorrhoeae in vitro susceptibility test methods for cefixime including quality control guidelines

Cefixime was tested in a multilaboratory study to establish susceptibility testing interpretive criteria and quality control (QC) guidelines for Neisseria gonorrhoeae. Interpretive criteria were established by using triplicate testing of 102 representative gonococcal strains. Only a susceptible category was proposed for cefixime (greater than or equal to 31 mm and less than or equal to 0.25 micrograms/ml) because of very rare, resistant isolates. QC ranges [N. gonorrhoeae American Type Culture Collection (ATCC) 49226] were established using multiple GC agar lots, three disk lots, and a number of test replicates consistent with the National Committee for Clinical Laboratory Standards (NCCLS) M23-T guidelines. Cefixime was stable in GC agar medium for at least 21 days when stored at 2 degrees-5 degrees C. Oral third-generation cephalosporins, such as cefixime, appear to represent potentially useful clinical alternatives to parenteral drugs of the same class for single-dose therapy of gonorrhea.