Randomized comparative study of 0.5 and 1 g of cefodizime (HR 221) versus 1 g of cefotaxime for acute uncomplicated urogenital gonorrhea

The use of cephalosporins for gonorrhea: the impending problem of resistance

Gonorrhea remains an important clinical and public health problem throughout the world. Gonococcal infections have historically been diagnosed by Gram stain and culture but are increasingly diagnosed through nucleic acid tests, thereby eliminating the opportunity for antimicrobial susceptibility testing. Gonococcal infections are typically treated with single-dose therapy with an agent found to cure > 95% of cases. Unfortunately, the gonococcus has repeatedly developed resistance to antimicrobials including sulfonamides, penicillin, tetracyclines and fluoroquinolones. This has now left third-generation cephalosporins as the lone class of antimicrobials recommended as first-line therapy for gonorrhea in some regions. However, resistance to oral third-generation cephalosporins has emerged and spread in Asia, Australia and elsewhere. The mechanism of this resistance seems to be associated with a mosaic penicillin binding protein (penA) in addition to other chromosomal mutations previously found to confer resistance to beta-lactam antimicrobials (ponA, mtrR, penB, pilQ). Few good options exist or are in development for treating cephalosporin-resistant isolates, as most have had multidrug resistance. Preventing the spread of resistant isolates will depend on ambitious antimicrobial management programs, strengthening and expanding surveillance networks, and through effective sexually transmitted disease control and prevention.

Interpretive criteria for cefodizime in vitro susceptibility tests with Neisseria gonorrhoeae

Cefodizime was tested against 100 strains of Neisseria gonorrhoeae with varying susceptibility patterns to penicillin. Agar-dilution minimum inhibitory concentrations (MIC) and disk diffusion susceptibility testing were performed in triplicate for each strain according to National Committee for Clinical Laboratory Standards (NCCLS) guidelines to establish susceptibility interpretive criteria for this beta-lactamase-stable cephalosporin. Cefodizime was very active against these strains of N. gonorrhoeae, with a MIC50 of only 0.008 microgram/ml. Because no resistant strains were documented, a single susceptible criterion of < or = 0.05 microgram/ml (> or = 31 mm) was proposed to predict clinical success after a single intramuscular (i.m.) dose.

The value of new antimicrobial agents

New antimicrobial agents require careful assessment to determine whether they possess the appropriate properties for clinical use. Many new compounds of value in the prophylaxis and therapy of infections have been included in the current armamentarium. Close monitoring to identify possible adverse effects of new agents is essential. Alternative uses of older agents also expands therapeutic opportunities in the combat against infectious diseases. Inappropriate use of antimicrobial agents contributes to the worldwide problem of increasing bacterial resistance. The dramatic spread of such bacterial strains is partially responsible for the rising costs of infectious diseases. A rational and strict antibiotic policy is thus of great importance for the optimal use of these agents.

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

Cefodizime is a third generation cephalosporin with a broad spectrum of antibacterial activity. Administered intravenously or intramuscularly, cefodizime 1 to 4 g daily for an average of 7 to 10 days produced clinical cure in 80 to 100% of patients (adults, elderly or children) with upper or lower respiratory tract infections or urinary tract infections, and in comparative trials cefodizime was as effective as other third generation cephalosporins. A single dose of cefodizime 1 or 2 g is also useful in treating lower urinary tract infections, particularly uncomplicated infections, with a rate of clinical success of 72 to 88%. Urogenital gonorrhoea, whether caused by beta-lactamase producing or non-beta-lactamase producing Neisseria gonorrhoeae, is very effectively treated by single dose therapy with intramuscular cefodizime 0.25 to 1 g (virtually 100% cured). Preliminary data from a small number of patients indicate that cefodizime may also be useful in the treatment of otitis media, sinusitis and gynaecological infections, and for the prophylaxis or treatment of surgical infections. The clinical efficacy of cefodizime in comparison with other third generation cephalosporins is superior to that predicted from in vitro results. This superior activity of cefodizime may be related to the relatively long elimination half-life of the drug or its ability to modify some functions of the immune system--a potentially important finding awaiting further investigation. Cefodizime is well tolerated and has a tolerability profile similar to other members of its class with systemic adverse events being primarily gastrointestinal or dermatological. Thus, limited comparative studies indicate cefodizime has the potential to become a useful alternative to current antimicrobial therapy for the treatment of a variety of infections. Cefodizime may be more convenient to administer than some other agents of its class as it may be given once or twice daily. While there are no trials comparing cefodizime to other third generation cephalosporins in immunosuppressed populations, preliminary information indicates cefodizime may be useful in this group.

Treatment of acute gonococcal infections in Bangkok with a dose range of the new cephalosporin, cefodizime

In this randomized dose range study conducted in Bangkok, 326 patients with presumed acute uncomplicated gonorrhoea were treated with a single intramuscular dose of either 0.25 g, 0.5 g, or 1.0 g of a new aminothiazole cephalosporin, cefodizime. One hundred and eighty men and 110 women were evaluable for efficacy. Pathogens were eliminated in all but 4 of these patients resulting in a cure rate of 99%, irrespective of dose, sex, or multiplicity of infected sites. A high percentage of the 290 strains of Neisseria gonorrhoeae isolated from the evaluable patients showed resistance to penicillin, and 40% were penicillinase producing (PPNG). The minimum inhibitory concentration of cefodizime for 90% of the PPNG strains was less than 0.04 mg/l. No clinically relevant adverse drug reactions were reported. This study demonstrates that a single 0.25 g dose of cefodizime is effective against both PPNG and non-PPNG strains in a geographic region characterized by high endemic antibiotic resistance.

In vitro activity of cefodizime

Cefodizime is a bactericidal cephem with the typical broad spectrum activity of an aminothiazolyl cephalosporin, including both gram-positive and gram-negative bacteria: its MIC90 is 0.125 mg/l for Streptococcus pneumoniae, Streptococcus pyogenes and other streptococci; and 0.05 mg/l for Haemophilus spp., Neisseria meningitidis, Neisseria gonorrhoeae and Moraxella catarrhalis; while beta-lactamase positive strains of M. catarrhalis require 1 mg/l. Less than 1 mg/l is needed for Escherichia coli, Klebsiella spp., Proteus spp. and Shigella spp. The MIC90 is 4 mg/l for methicillin-sensitive Staphylococcus aureus, Morganella morganii, Providencia spp. and most strains of Serratia marcescens, Citrobacter spp. and Enterobacter spp. Staphylococcus epidermidis, Enterococcus faecalis and most strains of Pseudomonas spp. and Acinetobacter spp. are considered cefodizime-resistant. Cefodizime is unaffected by plasmid-mediated beta-lactamases, but it is hydrolyzed by some chromosomally mediated enzymes, thus resembling other third-generation cephalosporins. Cefodizime has high affinity for PBP 3 and PBP IA and IB (Escherichia coli); in S. aureus it shows the highest affinity for PBP 1.

Lectins and their application to clinical microbiology

Lectins are generally associated with plant or animal components, selectively bind carbohydrates, and interact with procaryotic and eucaryotic cells. Lectins have various specificities that are associated with their ability to interact with acetylaminocarbohydrates, aminocarbohydrates, sialic acids, hexoses, pentoses, and as other carbohydrates. Microbial surfaces generally contain many of the sugar residues that react with lectins. Lectins are presently used in the clinical laboratory to type blood cells and are used in a wide spectrum of applications, including, in part, as carriers of chemotherapeutic agents, as mitogens, for fractionation of animal cells, and for investigations of cellular surfaces. Numerous studies have shown that lectins can be used to identify rapidly certain microorganisms isolated from a clinical specimen or directly in a clinical specimen. Lectins have been demonstrated to be important diagnostic reagents in the major realms of clinical microbiology. Thus, they have been applied in bacteriology, mycology, mycobacteriology, and virology for the identification and/or differentiation of various microorganisms. Lectins have been used successfully as epidemiologic as well as taxonomic markers of specific microorganisms. Lectins provide the clinical microbiologist with cost-effective and potential diagnostic reagents. This review describes the applications of lectins in clinical microbiology.

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

In an open, dose-finding study, a 100% cure rate was observed in patients suffering from uncomplicated gonococcal urethritis who were treated with a single oral dose of either 1.2 g (n = 10), 0.8 g (n = 11), or 0.4 g (n = 10) of cefetamet pivoxil. The MICs of cefetamet for all gonococcal strains ranged from 0.001 to 0.12 micrograms/ml, and the MIC for 90% of the strains tested was 0.008 micrograms/ml. Cefetamet pivoxil was ineffective against Chlamydia trachomatis in 3 of 31 patients. Side effects were minor.