Review of the new second-generation cephalosporins: cefonicid, ceforanide, and cefuroxime

Effectiveness of Oral Cephalexin-Clavulanic Acid, Cefuroxime, and Amoxicillin-Clavulanic Acid in the Management of Dental Infections: A Real-World, Retrospective, Electronic Medical Record-Based Study in India

BACKGROUND

Despite multiple antibiotics being available to manage dental infections (DI), there is lack of data comparing commonly prescribed antibiotics in India.

OBJECTIVES

The aim of this study was to evaluate the real-world effectiveness and tolerability of cephalexin-clavulanic acid fixed-dose combination (cephalexin CV FDC) in contrast with amoxicillin-clavulanic acid (co-amoxiclav FDC) and cefuroxime among patients with dental infections (odontogenic) in India.

METHODS

This retrospective, multi-centric, observational, real-world electronic medical record (EMR)-based study was conducted between January 2022 and December 2022. The EMRs of 355 adults with DI receiving oral cephalexin CV, co-amoxiclav, or cefuroxime were categorized into two distinct groups: Group I (Test Group) with patients prescribed cephalexin extended release 375/750 mg along with clavulanic acid 125 mg; and Group II (Comparator Group) with patients prescribed co-amoxiclav 625 mg (500 mg amoxicillin + 125 mg clavulanic acid) or cefuroxime (250 mg/500 mg).

RESULTS

Toothache was the most common complaint, reported by 95.5% of patients, followed by swelling (46.8%), tooth sensitivity (35.5%), pus discharge (33.0%), redness and halitosis (30.4% each). Dental caries was observed in 81.1% of patients. Clinical improvement, defined as improvement/partial resolution of infection-related clinical signs and symptoms (composite measure of pain, swelling, fever, requirement of additional antimicrobial therapy) as per dentists' judgment, was recorded in 98.3% of patients with cephalexin CV, 96.8% of patients with co-amoxiclav, and 98.9% of patients treated with cefuroxime within 10 days. Time (days) to clinical improvement was numerically lesser among patients receiving cephalexin CV (4.6 ± 2.0) compared with cefuroxime (4.9 ± 2.1) and co-amoxiclav (5.0 ± 2.6). All treatments were well tolerated.

CONCLUSION

Cephalexin CV was as effective as co-amoxiclav and cefuroxime, with faster clinical improvement and better resolution of certain symptoms.

Cephalosporins as key lead generation beta-lactam antibiotics

Abstract

Antibiotics are antibacterial compounds that interfere with bacterial growth, without harming the infected eukaryotic host. Among the clinical agents, beta-lactams play a major role in treating infected humans and animals. However, the ever-increasing antibiotic resistance crisis is forcing the pharmaceutical industry to search for new antibacterial drugs to combat a range of current and potential multi-resistant bacterial pathogens. In this review, we provide an overview of the development, innovation, and current status of therapeutic applications for beta-lactams with a focus on semi-synthetic cephalosporins. Cephalosporin C (CPC), which is a natural secondary metabolite from the filamentous fungus Acremonium chrysogenum, plays a major and demanding role in both producing modern antibiotics and developing new ones. CPC serves as a core compound for producing semi-synthetic cephalosporins that can control infections with different resistance mechanisms. We therefore summarize our latest knowledge about the CPC biosynthetic pathway and its regulation in the fungal host. Finally, we describe how CPC serves as a key lead generation source for the in vitro and better, in vivo synthesis of 7-aminocephalosporanic acid (7-ACA), the major core compound for the pharmaceutical synthesis of current and future semi-synthetic cephalosporins.

Key points

•Latest literature on cephalosporin generations

•Biotechnical production of cephalosporins

•In vivo production of 7-ACA

Cefonicid Benzathine Salt: A Convenient, Lean, and High-Performance Protocol to Make an Old Cephalosporin Shine

Cefonicid is a second-generation cephalosporin sold under the brand name Sintocef™. It is an injectable drug obtained via a freeze-drying process and is also available for oral preparations. The high-quality standard required is very challenging to satisfy, and current production protocols are characterized by steps that are lengthy and cumbersome, making the product unattractive for the international market. Industrial R&D is constantly working on the process optimization for API synthesis, with the aim of increasing productivity and decreasing production costs and waste. We herein report a new and efficient method for the synthesis of the cefonicid benzathine salt that provides a good yield and high product stability. The double-nucleophilic and lipophilic nature of N',N″-dibenzylethylene diacetate enables the deformylation of the OH-protected group on the mandelic moiety and also enables product crystallization to occur. We demonstrate that the formyl group in the peculiar position has high reactivity, promoting an amidation reaction that deprotects a hydroxy group and generates a new C-N bond in the reaction by-product. Several amines and OH-protected groups have been studied, but none were able to replicate the excellent results of benzathine diacetate.

A Straightforward Approach to Synthesize 7-Aminocephalosporanic Acid In Vivo in the Cephalosporin C Producer Acremonium chrysogenum

The pharmaceutical industry has developed various highly effective semi-synthetic cephalosporins, which are generated by modifying the side chains of the core molecule 7-aminocephalosporanic acid (7-ACA). In industrial productions, the 7-ACA nucleus is obtained in vitro from cephalosporin C (CPC) by chemical or enzymatic processes, which are waste intensive and associated with high production costs. Here, we used a transgenic in vivo approach to express bacterial genes for cephalosporin C acylase (CCA) in the CPC producer Acremonium chrysogenum. Western blot and mass spectrometry analyses verified that the heterologous enzymes are processed into α- and β-subunits in the fungal cell. Extensive HPLC analysis detected substrates and products of CCAs in both fungal mycelia and culture supernatants, with the highest amount of 7-ACA found in the latter. Using different incubation times, temperatures, and pH values, we explored the optimal conditions for the active bacterial acylase to convert CPC into 7-ACA in the culture supernatant. We calculated that the best transgenic fungal strains exhibit a one-step conversion rate of the bacterial acylase of 30%. Our findings can be considered a remarkable contribution to supporting future pharmaceutical manufacturing processes with reduced production costs.

Second-Generation Cephalosporins-Associated Drug-Induced Liver Disease: A Study in VigiBase with a Focus on the Elderly

Background: The objective of this study was to characterize individual case safety reports (ICSRs) and adverse drug reactions (ADRs) related to second-generation cephalosporins and resulting in hepatobiliary disorders, in VigiBase, WHO global database. Methods: All second-generation cephalosporins hepatobiliary ADRs reported up to July 2019 were included. Characteristic of cephalosporins and ADRs, aside from disproportionality data were evaluated. Results: A total of 1343 ICSRs containing 1585 ADRs were analyzed. Cefuroxime was suspected to have caused hepatobiliary disorders in most cases—in 38% of adults and in 35% of elderly. Abnormal hepatic function was the most frequent ADR, followed by jaundice and hepatitis. For 49% of the ADRs reported in the elderly and 51% in the adult population, the outcome was favorable, with fatal outcome for 2% of the adults and 10% of the elderly. Higher proportional reporting ration (PRR) values were reported in the elderly for cefotetan-associated jaundice, cefuroxime-associated acute hepatitis and hepatitis cholestatic as well as for cefotiam and cefmetazole-associated liver disorder. Conclusion: Hepatobiliary ADRs were reported for 2nd generation cephalosporins, with over 50% of cases in adults, without gender differences. Cholestatic hepatitis was predominately reported in the elderly and this category was more prone to specific hepatic reactions.

Perioperative antibiotic prophylaxis with cefuroxime in oral-maxillofacial surgical procedures

A study was carried out to investigate the suitability of cefuroxime for perioperative antibiotic prophylaxis in maxillofacial surgical procedures. Serum and tissue samples were taken, to determine the intraoperative cefuroxime concentration, from 40 patients who had been given 1.5 g cefuroxime (Zinacef) i.v. during maxillofacial surgery. The time between i.v. administration and taking the blood and tissue samples varied between 10 and 260 min. The serum tissue kinetics were determined using an HPLC method in the jaw area, particular emphasis being given to the concentrations measured in bone. It was demonstrated that concentrations of cefuroxime were reached which are above the MIC values for many of the pathogens in the maxillofacial area and therefore adequate protection during intraoperative bacterial contamination is guaranteed. Maximum serum levels averaging 80 mg/l were measured within 30 min of administration. An average of 15 mg/l could still be demonstrated after 4 h. The bone samples gave maximum levels of 8-9 mg/kg 90 min after administration. Average levels of 1-3 mg/kg were still measurable after 4 h. It is only possible to describe trends due to the wide variation in the values, particularly of the bone samples. No postoperative wound infection was seen under prophylaxis with cefuroxime. Cefuroxime is suitable for perioperative prophylaxis during maxillofacial surgery procedures because of its favourable kinetics and broad spectrum of action.

High pressure liquid chromatographic analysis of the serum concentration of cefuroxime after an intravenous bolus injection of cefuroxime in patients with a coronary artery bypass grafting

A simple reversed-phase high pressure liquid chromatographic method was developed for the determination of cefuroxime in the serum of patients undergoing coronary artery bypass grafting. The serum was cleaned up with a 3.3% solution of perchloric acid in water. Cefalexine was used as an internal standard. Detection was made by a UV multi-wavelength detector. The optimum wavelength for cefuroxime is 275 nm. The absolute recovery of this method was 90.9%; the limit of quantification was 0.7 mg/l. This analytical method was used in a study to investigate the cefuroxime serum concentration--time curves in 26 patients undergoing coronary artery bypass grafting. It was found that one single dose is sufficient to obtain effective serum concentrations.

Atypical pneumonias. Clinical diagnosis and empirical treatment

Atypical pathogens play an important role in the pathogenesis of community-acquired pneumonias. Early definitive diagnosis is often difficult. Careful attention must be given to the patient's history and other diagnostic clues. When a specific pathogen seems very likely to be the cause, appropriate and cost-effective empirical therapy is best accomplished with a single-drug regimen. However, when typical and atypical pathogens are suspected, combination drug therapy is preferred until the diagnosis is firm and one of the two antibiotics can be dropped.

Evaluation of cefonicid use in a general hospital

Recently marketed drugs have limited experience in clinical use. Follow-up evaluation is therefore needed, particularly when these drugs are "restricted use" medicines, such as the second-generation cephalosporins. We present a follow-up of the first use of cefonicid, which was carried out after its substitution for cefuroxime in our hospital. The indication for use, dosing, therapeutic effects, and possible adverse reactions were recorded in 210 of the first 319 medical-surgical inpatients who received cefonicid. Cefonicid was administered to patients who could have been treated with free-use antibiotics on at least 128 occasions; these were cases of community-acquired pneumonia without any risk factor, urinary tract infections, acute exacerbations in patients with chronic lung disease, surgical prophylaxis, and intraabdominal infections. One fatal case of Stevens-Johnson syndrome was seen. Other recorded adverse events were two skin reactions, one tachyarrhythmia with evidence of low cardiac output, six episodes of phlebitis, and nine superinfections during treatment with cefonicid. The use of cefonicid instead of cefuroxime was associated with 20 percent cost savings; however, this study shows that optimal antibiotic prescribing may produce much greater savings.

Absolute bioavailability of cefixime in man

In a four-way cross-over study, the absolute bioavailability of cefixime was determined in 16 healthy volunteers. Each subject received a single 200-mg dose as an intravenous (IV) and oral solution, and 200-mg and 400-mg capsule doses of the drug. Blood and urine samples were collected for 24 hours after each dose. Cefixime was well tolerated after IV and oral doses of the drug and no serious drug-related adverse effects were observed. The maximal serum concentration (Cmax) of cefixime following the 200-mg oral solution and 200-mg and 400-mg capsule doses were 3.22, 2.92, and 4.84 micrograms/mL, respectively. Mean area under the serum concentration time curves (AUC) following the IV, 200-mg oral solution, and 200-mg and 400-mg capsule doses were 47.0, 26.0, 23.6, and 39.4 micrograms.hr/mL, respectively. Mean elimination half-life values of the drug were comparable after oral and IV doses, ranging from 3.2 to 3.5 hours. Based on serum AUC values, the absolute bioavailability of cefixime was 52.3%, 47.9%, and 40.2% after the 200-mg oral solution, 200-mg capsule and 400-mg capsule doses, respectively. Respective ratios based on 24-hour urinary recovery data were 44.7%, 41.7%, and 40.5%. Therefore, the results show that the percent of cefixime adsorbed after 200-mg and 400-mg oral doses was similar.

Ceforanide. A review of its antibacterial activity, pharmacokinetic properties and clinical efficacy

Ceforanide is a 'second generation' cephalosporin administered intravenously or intramuscularly. It is similar to cefamandole and cefonicid in its in vitro superiority to 'first generation' cephalosporins against several species of Enterobacteriaceae as well as its activity against Haemophilus influenzae, including beta-lactamase-producing strains. Its activity against Staphylococcus aureus is less than that of cefamandole, cefuroxime and first generation cephalosporins. The in vitro activity against Neisseria gonorrhoeae is excellent. Pseudomonas, Acinetobacter and Serratia species, and Bacteroides fragilis are resistant, as are many strains of Proteus and Providencia species. The elimination half-life is relatively long, although shorter than that of cefonicid, and in most clinical trials ceforanide has been administered twice daily. It appeared to be comparable in therapeutic efficacy to procaine penicillin and cephazolin in the treatment of patients with community-acquired pneumonia, to cephazolin in the treatment of skin and soft tissue infections due to S. aureus or beta-haemolytic streptococci and to cefapirin in S. aureus endocarditis in parenteral drug abusers. Also, it was comparable in efficacy to cephalothin in the prophylaxis of infection in patients undergoing open heart surgery or vaginal hysterectomy, and to cephazolin in patients undergoing cholecystectomy. Thus, ceforanide is an alternative to first and certain other second generation cephalosporins in several important therapeutic and prophylactic situations. It has no advantage over other cephalosporins with regard to spectrum of antibacterial activity, but has a longer half-life than other second generation cephalosporins, except cefonicid, and can be administered according to a twice daily dosage schedule.

Cephalosporin, carbapenem, and monobactam antibiotics

Cephalosporin and related antibiotics are highly effective bactericidal agents of relatively low toxicity. The spectrum of activity varies with the drug but is usually broad. The first-generation cephalosporins, and especially cefazolin, are most active against sensitive staphylococci and streptococci. Most second-generation (except cefoxitin) and third-generation cephalosporins show substantial activity against Haemophilus influenzae. All cephalosporins (except cefsulodin) are active against Klebsiella, Escherichia coli, and Proteus mirabilis, whereas only the third-generation agents have pronounced activity against the other Enterobacteriaceae. Imipenem (a carbapenem) is active against essentially all pathogenic organisms, but aztreonam (a monobactam) is active against only aerobic gram-negative bacilli. Advantages associated with some of the new cephalosporins are once-daily administration and high cerebrospinal fluid levels. With the development of new cephalosporins, however, new toxicities have become apparent, and superinfections and induction of resistance have become greater problems. The cephalosporins are among the most expensive antibiotics in use today; thus, use of these expensive agents must be justified by lower toxicity, greater efficacy, or both in comparison with drugs of more reasonable cost.