Comparison of cefprozil and cefaclor for treatment of acute urinary tract infections in women

Oral cephalosporin and β-lactamase inhibitor combinations for ESBL-producing Enterobacteriaceae urinary tract infections

ESBL-producing Enterobacteriaceae as uropathogens have given rise to a sizeable amount of global morbidity. Community and hospital surveillance studies continue to report increasing proportions of these organisms as causes of urinary tract infection (UTI). Due to limited treatment options and the presence of cross-resistance amongst oral antibiotics of different classes, patients often require IV therapy, thereby increasing healthcare costs and reducing the effectiveness of delivering healthcare. Oral cephalosporin antibiotics are well known for their ability to achieve high urinary concentrations, in addition to achieving clinical success for treatment of uncomplicated UTI with a drug-susceptible pathogen. Novel cephalosporin/β-lactamase inhibitor combinations have been developed and demonstrate good in vitro activity against ESBL-producing isolates. A pooled analysis of in vitro activity of existing oral cephalosporin/clavulanate combinations in ESBL-producing Enterobacteriaceae has shown MIC50s of 0.5-1, 0.125-1 and 0.25 mg/L for cefpodoxime, ceftibuten and cefixime, respectively. A novel cyclic boronic acid β-lactamase inhibitor, QPX7728, was able to produce MIC50 values of 0.5 and ≤0.06 mg/L when paired with cefpodoxime and ceftibuten, respectively. Other novel combinations, cefpodoxime/ETX0282 and ceftibuten/VNRX7145, have also demonstrated excellent activity against ESBL producers. Clinical trials are now awaited.

Antimicrobial pharmacokinetics and preclinical in vitro models to support optimized treatment approaches for uncomplicated lower urinary tract infections

INTRODUCTION

Urinary tract infections (UTIs) are extremely common. Millions of people, particularly healthy women, are affected worldwide every year. One-in-two women will have a recurrence within 12-months of an initial UTI. Inadequate treatment risks worsening infection leading to acute pyelonephritis, bacteremia and sepsis. In an era of increasing antimicrobial resistance, it is critical to provide optimized antimicrobial treatment.

AREAS COVERED

Literature was searched using PubMed and Google Scholar (up to 06/2020), examining the etiology, diagnosis and oral antimicrobial therapy for uncomplicated UTIs, with emphasis on urinary antimicrobial pharmacokinetics (PK) and the application of dynamic in vitro models for the pharmacodynamic (PD) profiling of pathogen response.

EXPERT OPINION

The majority of antimicrobial agents included in international guidelines were developed decades ago without well-described dose-response relationships. Microbiology laboratories still apply standard diagnostic methodology that has essentially remained unchanged for decades. Furthermore, it is uncertain how relevant standard in vitro susceptibility is for predicting antimicrobial efficacy in urine. In order to optimize UTI treatments, clinicians must exploit the urine-specific PK of antimicrobial agents. Dynamic in vitro models are valuable tools to examine the PK/PD and urodynamic variables associated with UTIs, while informing uropathogen susceptibility reporting, optimized dosing schedules, clinical trials and treatment guidelines.

An LC-MS/MS method for simultaneous determination of cefprozil diastereomers in human plasma and its application for the bioequivalence study of two cefprozil tablets in healthy Chinese volunteers

A rapid and sensitive liquid chromatography-tandem mass spectrometric method was developed for the first time and validated for the determination of cefprozil diastereomers in human plasma. The plasma samples were prepared by protein precipitation using acetonitrile. Detection was performed using an electronic spray ion source in the negative ion mode, operating in the multiple reaction monitoring of the transitions m/z 388.0 to m/z 205.0 for cefprozil diastereomers and m/z 346.1 to m/z 268.1 for cephalexin (the internal standard). The calibration curves of cis-cefprozil and trans-cefprozil were linear in the ranges 0.125-16.0 µg/mL and 0.0403-1.72 µg/mL, respectively. The lower limits of quantification of cis- and trans-cefprozil were 0.125 and 0.0403 µg/mL in human plasma, respectively. The intra- and inter-day precisions of cis- and trans-cefprozil were all <9.7%, and the accuracy ranged from 99.2 to 104.7% and from 100.6 to 102.2%, respectively. The validated method was successfully applied to a bioequivalence study of two cefprozil formulations in 24 healthy Chinese volunteers. The two cefprozil tablets were bioequivalent by measurement of cis-, trans- and total cefprozil. We suggest that the bioequivalence of cefprozil formulations can be evaluated only using cis-cefprozil as the analyte in future studies.

Comparison of cefprozil, cefpodoxime proxetil, loracarbef, cefixime, and ceftibuten

OBJECTIVE

To discuss the pharmacokinetics, spectrum of activity, clinical trials, and adverse effects of cefprozil, cefpodoxime proxetil, loracarbef, cefixime, and ceftibuten, an investigational cephalosporin.

DATA SOURCES

Literature was identified by a MEDLINE search from 1986 to January 1995.

STUDY SELECTION

Randomized, controlled studies were selected for evaluation; however, uncontrolled studies were included when data were limited for indications approved by the Food and Drug Administration.

DATA EXTRACTION

Data were evaluated with respect to in vitro activity, study design, clinical and microbiologic outcomes, and adverse drug reactions.

DATA SYNTHESIS

Cefprozil, cefpodoxime proxetil, loracarbef, cefixime, and cefributen are active in vitro against organisms frequently involved in community-acquired infections such as Streptococcus pneumoniae, Escherichia coli, beta-lactamase-positive or -negative Haemophilus influenzae, and Moraxella catarrhalis. Except for cefixime and ceflibuten, they all are active against methicillin-susceptible Staphylococcus aureus. Even though there were problems in study design (discussed within the text), clinical data demonstrate that these new oral beta-lactam compounds are as efficacious as conventional therapies for a variety of community-acquired infections.

CONCLUSIONS

Cefprozil, cefpodoxime, cefixime, loracarbef, and ceftibuten demonstrate in vitro activity against the major organisms that cause community-acquired infections. Clinical trials confirm that these agents are as effective as traditional therapies for the management of acute otitis media, pharyngitis/tonsillitis, sinusitis, bronchitis, pneumonia, urinary tract infections, and skin and skin-structure infections. In addition, cefixime and cefpodoxime are effective therapies for uncomplicated gonococcal infections. Selection of a specific agent will be influenced by susceptibility data and safety, as well as issues of compliance and cost.

Cefprozil. A review of its antibacterial activity, pharmacokinetic properties, and therapeutic potential

Cefprozil is an orally active cephalosporin which has demonstrated activity against a wide range of organisms in vitro. It is particularly active against the Gram-positive organisms Streptococcus pyogenes, pneumoniae and agalactiae and against methicillin-susceptible Staphylococcus aureus. Strains of methicillin-resistant S. aureus are not susceptible to cefprozil. Cefprozil is also moderately active against Haemophilus influenzae, Moraxella catarrhalis, Neisseria gonorrhoeae, many Enterobacteriaceae and certain anaerobic organisms, and is relatively stable to hydrolysis by a number of beta-lactamases. In comparative trials, the clinical and bacteriological efficacy of cefprozil 500mg or 20 mg/kg administered once or twice daily has been comparable with multiple daily dosage regimens of erythromycin in patients with tonsillitis or pharyngitis, with cefaclor and amoxicillin/clavulanate in lower respiratory tract infections, with amoxicillin/clavulanate and erythromycin in skin and skin-structure infections and with cefaclor in acute uncomplicated urinary tract infections. The clinical efficacy of cefprozil is similar to that of cefaclor in patients with tonsillitis or pharyngitis but the bacteriological efficacy of cefprozil is significantly greater than that of cefaclor. Cefprozil is clinically more effective than cefuroxime axetil in the treatment of lower respiratory tract infections and demonstrated greater efficacy than cefaclor in one of 2 comparative studies when administered twice daily in patients with skin and skin-structure infections. In children with acute otitis media, cefprozil 15 mg/kg twice daily was as effective as cefaclor or amoxicillin/clavulanate 13.3 mg/kg 3 times daily and was as effective as cefixime 8 mg/kg once daily. The most frequently reported adverse effects associated with cefprozil, diarrhoea and nausea, are usually mild to moderate in severity and discontinuation of treatment is rarely necessary. Thus, cefprozil with its convenient administration regimen appears to be a suitable alternative to cefaclor, cefixime, amoxicillin/clavulanate or erythromycin for the treatment of upper and lower respiratory tract infections, skin and skin-structure infections, and otitis media in children. While cefprozil has shown similar efficacy to cefaclor in the treatment of uncomplicated urinary tract infections, well-controlled clinical trials comparing its efficacy with that of cotrimoxazole (trimethoprim+sulfamethoxazole) in this indication are required.

Antibiotic therapy for urinary tract infections

Loracarbef, a member of the carbacephem class of beta-lactam antibiotics, was tested in randomized, double-blind, parallel studies for the treatment of uncomplicated urinary tract infections (UTIs). In one study conducted in the United States, a 7-day course of once-daily doses of loracarbef (200 mg) was compared with a 7-day course of multiple daily doses of cefaclor (250 mg three times a day). Analysis of data from a small, homogeneous patient population of 108 college-aged women showed that loracarbef produced clinical and bacteriologic responses similar to those produced by cefaclor. At 5-9 days posttherapy, bacteriologic cure was observed in 96% of patients in the loracarbef group and 90% of patients in the cefaclor group (p = 0.614); at 4-6 weeks post-therapy, the same cure rate (81%) was observed in both groups. Analysis of the larger (333 patients) and more heterogeneous study population containing several male and elderly female patients showed that loracarbef again produced responses similar to those produced by cefaclor, with no statistically significant differences seen between the groups at 5-9 days or at 4-6 weeks posttherapy. The adverse events reported by the loracarbef and cefaclor groups were also comparable in both the small and large patient populations analyzed. Similarly favorable results were seen when a 7-day regimen of loracarbef (200 mg once a day) was compared with a 7-day regimen of norfloxacin (400 mg twice a day) in a large European study of approximately 300 patients with uncomplicated cystitis. These studies demonstrate that the safety and efficacy of once-daily loracarbef are comparable to the safety and efficacy of multiple-dose/day therapy with other antimicrobial agents commonly used in the treatment of uncomplicated UTIs.