Ceftriaxone is a new 'third generation' semisynthetic
cephalosporin with a long half-life which has resulted in a recommended once daily administration schedule. It is administered intravenously or intramuscularly and has a broad spectrum of activity against Gram-positive and Gram-negative aerobic, and some anaerobic, bacteria. The activity of
ceftriaxone is generally greater than that of the 'first' and '
second generation' cephalosporins against Gram-negative bacteria, but less than that of the earlier generations of
cephalosporins against many Gram-positive bacteria. Although
ceftriaxone has some activity against Pseudomonas aeruginosa, on the basis of present evidence it cannot be recommended as sole
antibiotic therapy in pseudomonal
infections.
Ceftriaxone has been effective in treating
infections due to other 'difficult' organisms such as multidrug-resistant Enterobacteriaceae.
Ceftriaxone was effective in complicated and uncomplicated
urinary tract infections, lower
respiratory tract infections, skin, soft tissue, bone and joint
infections, bacteraemia/septicaemia, and paediatric
meningitis due to susceptible organisms. In most of these types of
infections once-daily administration appears efficacious. Results were also encouraging in a few patients with ear, nose and throat, intra-abdominal, obstetric and gynaecological
infections, and adult
meningitis, but conclusions are not yet possible as to the efficacy of the
drug in these indications due to limited experience. A single intramuscular dose of
ceftriaxone has been compared with standard
therapy for gonorrhoea due to non-
penicillinase-producing and
penicillinase-producing strains of Neisseria gonorrhoeae and shown to be highly effective. In a few small trials the comparative efficacy of
ceftriaxone and other antibacterials has been assessed in other types of
infections and in perioperative prophylaxis in patients undergoing surgery. Few significant differences in response rates were found between therapeutic groups in these comparative studies, but larger well-designed studies are needed to more clearly assess the comparative efficacy of
ceftriaxone and other antimicrobials, especially the
aminoglycosides and other '
third generation' cephalosporins, and to confirm the apparent lack of serious side effects with
ceftriaxone. If more widespread use confirms the safety and efficacy of
ceftriaxone, it will offer an important alternative, particularly for the treatment of serious
infections due to multidrug-resistant Gram-negative bacteria and in situations where the long half-life of the
drug could result in worthwhile convenience and cost benefits.