Cefetamet pivoxil

Cefetamet pivoxil, because of its activity against respiratory pathogens and its pharmacokinetic behaviour, is expected to have clinical efficacy in the treatment of lower respiratory tract infection (LRTI). This paper presents an overview of clinical trials conducted worldwide to investigate the efficacy and tolerability of cefetamet pivoxil in the treatment of adults and children with LRTI. A total of 626 adult patients, the majority of whom presented with exacerbations of chronic bronchitis (n = 500), received oral cefetamet pivoxil 500 or 1000mg twice daily for 5 to 10 days (n = 351) or a standard comparator agent (n = 275). The comparator agents were amoxicillin (750mg 3 or 4 times daily, or 1000mg twice daily), amoxicillin/clavulanic acid (625mg 3 times daily), or cefaclor (250 or 500mg 3 times daily) administered for 5 to 12 days. A satisfactory clinical outcome (cure + improvement) was achieved in 79 to 94% of evaluable patients. In 336 children, 240 received cefetamet pivoxil at 2 dosage levels (10 or 20 mg/kg twice daily) for 7 to 12 days and 96 received the standard comparator, cefaclor (10 mg/kg 3 times daily). Cefetamet pivoxil was clinically effective at both dosages, and did not differ significantly compared with cefaclor (clinical cure rates of 97 to 99% with cefetamet pivoxil and 96% with cefaclor). A separate analysis of 305 patients with community-acquired pneumonia showed clinical successes in 80 to 100% of adults, 75 to 78% of elderly patients, and 98% of children treated with cefetamet pivoxil.

Between 15 and 35% of pharyngeal infections are attributable to Group A beta-haemolytic streptococci. Streptococcal pharyngitis is one of the most common infections in adolescents and children. A specific diagnosis of pharyngitis can be obtained only by isolating organisms in culture. The current treatment of choice for streptococcal pharyngitis/tonsillitis is a 10-day course of phenoxymethylpenicillin (penicillin V); however, unresolved problems concerning the use of penicillin include the timing of therapy, appropriate therapy for treatment failures, chronic carriers and those with frequent recurrences. In addition, failure rates of 10 to 35% have been reported with oral phenoxymethylpenicillin. Effective treatment alternatives in this indication include oral cephalosporin agents or penicillin/beta-lactamase inhibitor combinations. The oral cephalosporins offer the advantage of an improved pharmacokinetic profile, once- or twice-daily administration, a shorter (7-day) regimen, and a low incidence of adverse effects, although these advantages must be balanced against the broad spectrum of these agents (broader than is necessary) and their cost. Clinical trials conducted with cefetamet pivoxil, a new oral third generation cephalosporin, in both adults and children with pharyngitis/tonsillitis indicate that this agent offers an effective alternative for phenoxymethylpenicillin in this indication.

Cefetamet pivoxil, the prodrug ester of cefetamet, is a new third-generation cephalosporin with a broad spectrum of activity. The in vitro activity of cefetamet was superior to that of cefaclor, ceftibuten, amoxicillin plus clavulanic acid, and amoxicillin alone when tested against 403 strains of freshly isolated upper and lower respiratory tract pathogens. Cefetamet killed 100% Haemophilus influenzae and H. parainfluenzae, including beta-lactamase-producing strains, at < or = 0.25 mg/l, Streptococcus pyogenes and S. pneumoniae at < or = 0.5 mg/l, S. agalactiae at < or = 0.1 mg/l, and streptococci at < or = 2.0 mg/l. Moreover, at < or = 4 mg/l (breaking point), cefetamet was also highly effective against Escherichia coli (94%), Klebsiella pneumoniae (92%), K. oxytoca (91%) and, at 1 mg/l, against Moraxella catarrhalis (90%), including beta-lactamase-producing strains. Furthermore, time-killing analyses at 4 x MIC demonstrated that cefetamet was bactericidal against beta-lactamase-producing H. influenzae, M. catarrhalis, and K. pneumoniae within 6 h and S. pneumoniae within 4 h. Hydrolysis studies confirmed cefetamet's stability to TEM1 and SHV1, the most common enterobacterial beta-lactamases.