Oral Beta-lactam Antibiotics Research Articles

Rise of the beta-lactams: a retrospective, comparative cohort of oral beta-lactam antibiotics as step-down therapy for hospitalized adults with acute pyelonephritis

Rise of the beta-lactams: a retrospective, comparative cohort of oral beta-lactam antibiotics as step-down therapy for hospitalized adults with acute pyelonephritis

The efficacy of pivmecillinam in oral step-down treatment in hospitalised patients with E. coli bacteremic urinary tract infection; a single-arm, uncontrolled treatment study

BackgroundThe role of oral beta-lactam antibiotics in treating febrile urinary tract infections (UTI) is not yet definite. Today, fluoroquinolones together with trimethoprim–sulfamethoxazole (TMP–MTX) are considered standard of care and often the only available evidence-based oral treatment for febrile UTI. This study clarifies the efficacy and safety of pivmecillinam (PIV) used as step-down therapy for bacteremic urinary tract infection (UTI).MethodsA single-arm, uncontrolled treatment trial was conducted in the period September 2017–March 2020. Candidates for inclusion were men and women suffering from E. coli bacteremia due to UTI and were consecutively included in a Norwegian hospital. Exclusion criteria were among others: other ongoing bacterial infection, septic shock, pyonephrosis/abscess and pregnancy. After 3 days of parenteral antibiotic, the treatment was converted to the study drug; oral PIV 400 mg QID for 1 week. Primary endpoint was a combination of three elements; afebrility, no need for retreatment and improvement in self-reported health status. Test Of Cure (TOC) was 1 week post-treatment. Secondary endpoints included among others microbiological efficacy and CRP value < 30 mg/L.ResultsOf 476 screened subjects, 53 patients were included. Median age was 67 years, 28 (56%) were women. 50 patients were evaluated for per-protocol analysis. 44 of 50 patients (88%) (95% CI [75.7–95.5]) reached the primary endpoint on TOC. 14 of 48 patients (29.2%) had significant growth (> 103 CFU/mL) of E.coli on TOC. CRP-level was strongly associated to treatment outcome, (OR 0.006 [95% CI 0.00–0.11], p < 0.001).ConclusionsThis trial documents that PIV 400 mg QID given for 1 week following 3 days of parenteral antibiotics, is a suitable treatment option in patients suffering from bacteremic UTI due to E. coli. Randomised clinical trials studying the efficacy of PIV vs standard of care of febrile UTI are warranted.Trial registration The trial was registered at ClinicalTrials.gov under the identifier: NCT03282006 13/09/2017 and approved by The Regional Committees for Medical Research Ethics South East Norway (2015/2384/REK sør-øst) and the Norwegian Medicines Agency (SLV; reference No 16/06018-09; EudraCT No 2016-000984-18) before initiation

Hypoglycemia associated with pivalate-conjugated antibiotics in young children: A retrospective study using a medical and pharmacy claims database in Japan

IntroductionAcute bacterial infectious diseases are major causes for outpatient visits for young children. Pivalate-conjugated antibiotics (PCAs) are frequently prescribed for these situations in Japan, while several literatures have shown a potential risk of hypoglycemia associated with PCAs. This study aimed to evaluate the incidence of PCA-induced hypoglycemia in children, compared with other oral beta-lactam antibiotics. MethodsThis retrospective cohort study using a Japanese medical and pharmacy claims database was performed on children aged 1 month to 5 years old with at least once prescription of PCAs or other oral beta-lactam antibiotics from January 2011 to December 2013. Hypoglycemia was defined based on diagnostic codes or the prescription of 10% or 20% glucose injection. We examined the prevalence of hypoglycemic events and performed multivariate analysis to investigate the risk of hypoglycemia with PCAs compared with the control oral beta-lactam antibiotics. ResultsWe identified 179,594 eligible patients in this population. In the PCA and control groups, there were 454,153 and 417,287 prescriptions and 3356 (0.74%, 95% confidence intervals [CI] 0.71–0.76) and 2605 (0.62%, 95% CI 0.60–0.65) hypoglycemic events, respectively. Multivariate analysis revealed that PCAs were associated with hypoglycemia (adjusted odds ratios [OR] 1.18, 95% CI 1.12–1.24), and even a shorter duration of PCAs prescribing (≤7 days) was significantly associated with hypoglycemia (adjusted OR 1.17, 95% CI 1.11–1.24). ConclusionThese results suggest that in young children PCA use, even for a short period, is a risk factor of hypoglycemia.

Low dose oral beta-lactamase protects the gut microbiome from oral beta-lactam-mediated damage in dogs

Antibiotics, while lifesaving, damage the gut microbiome and can precipitate proliferation of pathobionts. A strategy to preserve gut microbiome integrity is to eliminate biologically active antimicrobials excreted into the gastrointestinal tract (GI) without negatively affecting antibiotic therapeutic efficacy. Clinical proof of concept was achieved with SYN-004 (ribaxamase), a beta-lactamase enzyme formulated for oral delivery with intravenous penicillins and cephalosporins. Ribaxamase inactivated intestinal ceftriaxone, protected the gut microbiome, and significantly reduced the incidence of Clostridioides difficile disease. For use with oral beta-lactam antibiotics, a delayed release formulation of ribaxamase, SYN-007, was engineered for dissolution in the lower small intestine distal to the site of oral antibiotic absorption. In dogs that received oral amoxicillin, SYN-007 reduced microbiome disruption without interfering with amoxicillin systemic absorption. Here, a study to determine the lowest effective dose of SYN-007 was performed. Dogs received amoxicillin (40 mg/kg, PO, TID) +/− SYN-007 (PO, TID) at three doses, 10 mg, 3 mg, or 1 mg for five days. Serum amoxicillin levels, measured after the first and last antibiotic doses, were not significantly different +/−SYN-007 at all dose levels indicating that SYN-007 did not interfere with amoxicillin systemic absorption. Microbiome analyses demonstrated that amoxicillin significantly reduced bacteria richness and microbiome diversity resulting in altered microbiome composition. However, with all doses of SYN-007, microbiome richness and diversity were not significantly different from pretreatment and changes in microbiome composition were attenuated. These data demonstrate that effective SYN-007 doses can be reduced at least 10-fold while maintaining gut microbiome preservation. The potential to employ low SYN-007 doses to protect the gut microbiota has important implications for enhancing therapeutic outcomes for patients receiving oral beta-lactam antibiotics while simultaneously reducing cost per dose and ultimately, healthcare expenses.

Quiz: Sternoclavicular Joint Swelling in a Previously Healthy Adult

A 77-year-old woman was admitted to our department because of 30-day history of low grade fever (up to 38.5°C) and pain in the left sternoclavicular joint. Twenty days before admission a progressively worsening swelling of the area occurred. She did not report any trauma and apart from low grade fever, the patient had also general symptoms such as loss of appetite, weakness and malaise. Her past medical history revealed only mild arterial hypertension. The patient had never received any kind of immunosuppression in the past whereas, there was no history of tuberculosis, diabetes mellitus, iv drug abuse, immune dysfunction or other known risk factors which have been associated with the presence of sternoclavicular joint infection (SCJI) [1]. She had been treated previously by her own general practitioner for 10 days before admission with oral beta-lactam antibiotic and cephalosporin without any improvement. On admission, physical examination revealed a dolorous, inflammatory lesion of the left sternoclavicular joint (Figure 1) and movement limitation of the left arm, whereas there was no ascites or peripheral lymphadenopathy. Laboratory work-up showed only moderate elevation of CRP (5.7 mg/dL; upper normal limit < 1 mg/dL), increased erythrocyte sedimentation rate (ESR; 66 mm/1h), positive tuberculin test (20 mm) while chest x-ray was normal. MRI of the area showed mild osteomyelitis of the clavicle and cellulitis of the surrounding tissues with no effusion at SCJ. The CT scans of the thorax, upper and lower abdomen and retroperitoneal space revealed no lymphadenopathy or pulmonary lesions. After drawing several sets of blood cultures, treatment with daptomycin was started at a dose of 8 mg/kg/day. We chose daptomycin as unfortunately in our area the rates of communityand hospital-associated methicillin resistant Staphylococcus aureus (MRSA) infections have been increased from 14.5% in 2000 up to 40-50% in 2006 and 65% in 2007-2009 [2,3]. Therefore, in our practice we usually manage severe infections of soft tissues, bone or spine initially with vancomycin, teicoplanin or daptomycin until a positive culture with sensitivity tests was obtained [4].

Inhibitory effect of zinc on PEPT1-mediated transport of glycylsarcosine and beta-lactam antibiotics in human intestinal cell line Caco-2.

The aim of this study was to examine the effects of zinc on the intestinal peptide transporters (PEPT1 and basolateral peptide transporter) and to elucidate the mechanism of the interactions. Caco-2 cells were pretreated with zinc, and the uptake studies were carried out. Zinc treatment resulted in the inhibition of [14C]glycylsarcosine (Gly-Sar) uptake via PEPT1 in a concentration-dependent manner, whereas it showed moderate inhibitory effect on the basolateral peptide transporter. Zinc also inhibited the uptake of oral beta-lactam antibiotics such as ceftibuten and cephradine by PEPT1. Kinetic analysis showed that zinc treatment increased Km values without affecting Vmax values of the [14C]Gly-Sar uptake. The inhibition of [14C]Gly-Sar uptake induced by zinc was observed in the presence of an H+ gradient but not in the absence of an H+ gradient. These results indicate that zinc is a competitive inhibitor of PEPT1. Zinc inhibited the PEPT1 function, possibly by interacting with histidine residues of PEPT1 that are part of an H+-binding site. These findings would provide important information for clinical, physiologic, and biochemical aspects of peptide transporters.

In vitro activity and pharmacodynamics of oral beta-lactam antibiotics against Streptococcus pneumoniae from southeast Missouri.

To determine the frequency of reduced susceptibility to penicillin, and to compare the in vitro activity and pharmacodynamics of oral beta-lactam antibiotics against clinical isolates of Streptococcus pneumoniae from southeast Missouri. Cape Girardeau, Missouri (population 35,500). Interventions. Minimum inhibitory concentrations (MICs) were determined for penicillin, amoxicillin, amoxicillin-clavulanic acid, cefprozil, cefuroxime, cefpodoxime, cefaclor, and loracarbef by E test for 108 isolates of S. pneumoniae. The MIC50, MIC90, and percentage susceptibility were calculated for each agent. Pharmacokinetic variables were obtained from the literature, and serum concentration-time profiles were simulated for a 25-kg child taking pediatric dosages commonly administered to treat otitis media. The average time above MIC (T > MIC) was calculated as percentage of the dosing interval using free concentrations and the MIC for each individual isolate. Analysis of variance (Scheffe post hoc test) was used to determine differences among agents for in vitro activity and T > MIC (level of significance, p<0.05). The frequency of penicillin-nonsusceptible S. pneumoniae was 28.7% (31/108). For 25 penicillin-intermediate isolates, amoxicillin and amoxicillin-clavulanic acid were significantly more active than cefprozil, cefaclor, and loracarbef. The T > MIC for amoxicillin and amoxicillin-clavulanic acid, simulated at 13.3 mg/kg every 8 hours, was significantly longer than that for all other beta-lactams. Amoxicillin and amoxicillin-clavulanic acid have superior in vitro activity and longer T > MIC for penicillin-intermediate isolates than the other oral beta-lactams.

Resistance against oral antibiotics to Streptococcus pneumoniae isolated from adult respiratory tract infections

The resistance against oral antibiotics to Streptococcus pneumoniae (S. pneumoniae) isolated from adult patients with respiratory tract infections in the Kurume area in 1998 was studied. The frequency of resistant strains, which were isolated penicillin-intermediate S. pneumoniae and resistant S. pneumoniae (PISP, PRSP) were both 41.2%. We examined the minimal inhibitory concentrations (MIC) of oral antibiotics and the susceptibility ratio of the strains for the drugs based on the breakpoint MIC. The breakpoint MIC of pneumonia against oral beta-lactam antibiotics to PISP, PRSP, which were determined by Japan Society of Chemotherapy, were high in the order of FRPM > CDTR, CFPN > CFTM > CFDN, CPDX. In the case of the new oral quinolones, DU6859a > SPFX > LVFX > CPFX showed good results, in this order, DU6859a showed the most significant inhibitory effect to PISP, PRSP (MIC90 0.06 microgram/ml). By serotyping the percentage of 19, 6, 23 was 42.9%, 21.4% and 14.3%.

Immunopharmacology of Oral Betalactams

Among the oral beta-lactam antibiotics only cefaclor has demonstrated a consistent in vitro and in vivo immunopharmacological effect which favors phagocytic chemotaxis and antimicrobial potential by inducing a T-helper 1 or pro-inflammatory response. Together with cefpimizole, cefaclor significantly reduces the minimum bactericidal concentration (MBC) against some bacterial species when cultured together with a suspension of polymorphonuclear leukocytes, as opposed to some other oral beta-lactams, co-amoxiclav and cefixime, which do not show this effect. The pro-inflammatory component of cefaclor's activity explains the clinical success of this antibiotic in a high percentage of cases, even when laboratory tests indicate in vitro resistance by the pathogen.

In vitro selection of one-step mutants of Streptococcus pneumoniae resistant to different oral beta-lactam antibiotics is associated with alterations of PBP2x.

Many oral penicillins and cephalosporins are used to treat clinical infections caused by Streptococcus pneumoniae. Therefore, using different beta-lactams as selectors, we estimated the frequencies of one-step mutations leading to resistance. Resistant mutants were obtained from penicillin-susceptible, intermediately resistant, and penicillin resistant strains. For cefixime, cefuroxime, cefpodoxime, cefotaxime, and ceftriaxone, the frequencies of mutation ranged from 10(-6) to 10(-8) when resistant mutants were selected at 2- to 8-fold the MIC, and the MICs increased 2- to 16-fold. For ampicillin, ampicillin-sulbactam, amoxicillin, amoxicillin-clavulanic acid, cefaclor, and loracarbef, the frequencies of mutation were about 10(-7) to 10(-8), and the MICs increased twofold at most. One to three resistance profiles of the resulting mutants were selected for each of the selecting antibiotics. Among those, some showed resistance to the cephalosporins associated with a 2- to 32-fold increase in susceptibility to the penicillins. Competition experiments showed a decreased affinity of PBP2x for cefpodoxime in all mutants. In some mutants that were more susceptible to amoxicillin, a decreased affinity of PBP2x for cefpodoxime was associated with an increased affinity for amoxicillin and a particular substitution of alanine for threonine at position 550 just after the KSG triad. From these results we infer (i) that among the beta-lactams tested the penicillins, cefaclor, and loracarbef selected one-step resistant mutants less frequently and that they achieved a lower level of resistance, and (ii) that mutants with different profiles may have acquired different point mutations in PBP2x.

Antibacterial activities of cefetamet against clinically isolated strains from community acquired respiratory tract infections (II)

Antibacterial activities of cefetamet (CEMT) against clinically isolated strains from patients with community acquired respiratory tract infections were compared to those of other oral beta-lactam antibiotics in the period from January to March 1994. The following results were obtained. 1. CEMT showed strong antibacterial activities against three major pathogens causing community acquired respiratory tract infections, Streptococcus pyogenes, Streptococcus pneumoniae, and Haemophilus influenzae. However, antibacterial activities of CEMT against benzylpenicillin (PCG)-insensitive S. pneumoniae (PISP) and PCG-resistant S. pneumoniae (PRSP) were slightly weaker than of those of some the reference antibiotics. 2. No MIC value changes of CEMT were observed from year to year against Moraxella subgenus Branhamella catarrhalis and Klebsiella pneumoniae.

Antimicrobial activity of RU29246 (HR916 metabolite) compared with four other oral beta-lactams tested against more than 5000 clinical isolates

The activity of RU29246, the active metabolite of the oral cephalosporin ester HR916, was compared in a multicenter study with that of the four oral beta-lactam antibiotics cephalexin, cefaclor, cefixime and amoxicillin/clavulanate (amoxicillin/CA). RU29246 was generally 2- to 8-fold more active than the other oral cephalosporins and comparable to amoxicillin/CA against staphylococci, and was the most active cephalosporin against group B streptococci. All four cephalosporins were ineffective against enterococci. RU29246 was the only cephalosporin consistently active against Acinetobacter, but all beta-lactam antibiotics had poor activity against Pseudomonas spp. and Xanthomonas maltophilia. RU29246 was comparable to cefixime and more active than the other cephalosporins against members of the family Enterobacteriaceae. However, all of the antibiotics had poor activity against Enterobacter cloacae and Serratia marcescens. Quality control reference ranges for the quality control organisms Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922 are proposed for the broth dilution method based on data derived from this multicenter study.

In vitro antibacterial properties of cefetamet and in vivo activity of its orally absorbable ester derivative, cefetamet pivoxil

The in vitro activity of cefetamet, the microbiologically active metabolite of the orally administered prodrug cefetamet pivoxil, was compared with that of cephalexin, cefaclor, cefuroxime and amoxicillin. Cefetamet was highly active against Enterobacteriaceae, Neisseria spp., Vibrio spp., Haemophilus influenzae and streptococci other than enterococci. Cefetamet inhibited cefaclor-resistant species such as Proteus vulgaris, Providencia stuartii, Providencia rettgeri and Serratia marcescens. Staphylococci, Pseudomonas aeruginosa and cephalosporinase-overproducing strains of Enterobacter cloacae were resistant to cefetamet. The superior activity of cefetamet compared with older oral beta-lactam antibiotics against a large number of gram-negative pathogens correlated with enhanced stability towards beta-lactamases. In accordance with the in vitro findings, cefetamet pivoxil showed good activity in experimental infections in the mouse and rat, suggesting satisfactory bioavailability in these animals after oral administration.

Influence of sultamicillin on intestinal bacterial flora

Effects of sultamicillin (SBTPC) fine granules, a new oral beta-lactam antibiotic, on the intestinal bacterial flora were studied in tetra-contaminated mice and in pediatric patients. SBTPC was administered at a dose of 100 mg/kg once a day for 5 consecutive days to mice contaminated with 4 different species of organisms: Escherichia coli, Enterococcus faecalis, Bacteroides fragilis and Bifidobacterium breve. In all of the 4 species, bacterial populations in feces were markedly reduced on days 4 to 5 after the start of the treatment. Subjects in the pediatric study were 5 children with bacterial infections (4 boys and 1 girl) at ages from 1 year 3 months to 10 years 8 months and with their body weight ranging from 11.8 kg to 35.0 kg. SBTPC fine granule was administered at a dose of 10 mg/kg 3 to 4 times a day for 4 to 7 days. Although there were some variations in the fecal bacterial flora noticed among these subjects during the treatment, populations of main aerobes and anaerobes such as Enterobacteriaceae, Enterococcus, Bacteroides and Bifidobacterium decreased markedly in all cases. These decreases were more pronounced for anaerobes and total numbers of anaerobes were markedly reduced in all cases. Glucose non-fermenting Gram-negative rods and fungi tended to increase with administration of SBTPC fine granule. Although these changes tended to return to pre-dosing state after the cessation of the treatment with SBTPC fine granule, attention must be paid to possible occurrences of diarrhea, superinfection or bleeding tendency when treatment with the drug is continued for a long period of time. Fecal concentrations of both ampicillin and sulbactam during SBTPC fine granule treatment showed relatively high values except 1 sample with a high beta-lactamase activity in feces. These high concentrations suggest the possibility of biliary excretion of absorbed drugs and the possibility of hydrolysis of SBTPC in the intestine due to high pH. Fecal concentrations of the drug also appeared to be closely related to beta-lactamase activity in feces.