Oral challenge vs routine care to assess low-risk penicillin allergy in critically ill hospital patients (ORACLE): a pilot safety and feasibility randomised controlled trial

PURPOSE

Critically ill patients are vulnerable to penicillin allergy labels that may be incorrect. The validity of skin testing in intensive care units (ICUs) is uncertain. Many penicillin allergy labels are low risk, and validated tools exist to identify those amenable to direct oral challenge. This pilot randomised controlled trial explored the feasibility, safety, and validity of direct enteral challenge for low-risk penicillin allergy labels in critical illness.

METHODS

Consenting patients with a low-risk penicillin allergy label (PAL) (PEN-FAST risk assessment score < 3) in four ICUs (Melbourne, Australia) were randomised 1:1 to penicillin (250 mg amoxicillin or implicated penicillin) direct enteral challenge versus routine care (2-h post-randomisation observation for each arm). Repeat challenge was performed post -ICU in the intervention arm. Patients were reviewed at 24 h and 5 days after each challenge/observation.

RESULTS

We screened 533 patients. 130 (24.4%) were eligible and 80/130 (61.5%) enrolled (age median 64.5 years (interquartile range, IQR 53.5, 74), PEN-FAST median 1 (IQR 0,1)), with 40 (50%) randomised to direct enteral challenge. A positive challenge rate of 2.5% was identified. No antibiotic-associated serious adverse events were identified. 32/40 (80%) received a repeat challenge (zero positive). Post-randomisation, 13 (32%) of the intervention arm and 4 (10%) of the control arm received penicillin (odds ratio, OR 4.33 [1.27, 14.78] p = 0.019).

CONCLUSION

These findings support the safety, validity, and feasibility of direct enteral challenge for critically ill patients with PEN-FAST assessed low-risk penicillin allergy. The absence of false negative results was confirmed by subsequent negative repeat challenges. A relatively low recruitment to screened ratio suggests that more inclusive eligibility criteria and integration of allergy assessment into routine ICU processes are needed to optimise allergy delabelling in critical illness.

Hoigné's syndrome, an uncommon mimicker of anaphylaxis: Systematic literature review

The term Hoigné's syndrome denotes a mimicker of anaphylaxis, which occurs immediately after the parenteral administration of a drug and is likely caused by non-thrombotic pulmonary and systemic drug micro-embolization. It has so far been documented uniquely in case reports and small case series. Because this condition has never been systematically evaluated, we performed a structured literature review (pre-registered as CRD42023392962). The search was carried out in Excerpta Medica, National Library of Medicine, and Google Scholar. Cases with features consistent with anaphylaxis, urticaria, angioedema, asthma, syncope, anxiety, or panic attack triggered by needle phobia, and local anesthetic systemic toxicity were excluded. For the final analysis, we retained reports published between 1951 and 2021, which presented 247 patients with Hoigné's syndrome: 37 children and 211 adults with a male: female ratio of 2.1 : 1.0. The patients presented within 1 min after parenteral administration of a drug (intramuscular penicillin in 90 % of the cases) with chest discomfort, shortness of breath, fear of death, psychomotor agitation, and auditory or visual hallucinations and impairment. Recovery occurred within 30 min. The diagnosis of Hoigné's syndrome was also established in five patients 66-91 years of age with pre-existing cardiovascular or pulmonary diseases, who suddenly died after the administration of penicillin despite not exhibiting the aforementioned symptoms. It was therefore speculated that pulmonary drug micro-embolization induced a lethal cardiovascular compromise in these individuals. Histologic investigations supporting this hypothesis were performed in only one case. The diagnosis of Hoigné's pulmonary drug micro-embolization was established also in five patients with pre-existing cardiovascular or pulmonary diseases, who suddenly died after the administration of penicillin despite not exhibiting the afore mentioned symptoms. Histologic investigations supporting this hypothesis were performed in only one case. In conclusion, Hoigné's syndrome is an uncommon non-immune-mediated reaction. This report seeks to promote broader awareness and knowledge regarding this alarming mimicker of anaphylaxis. Diagnosis relies solely on clinical evaluation.

A new pathway for penicillin delabeling in Norway

Background

Penicillin allergy is self-reported by 3-10% of patients admitted to hospital. The label is wrong in 90% of the cases and has severe health implications. Penicillin-delabeling can reverse the negative effects of the label, and pathways adapted to local practice are needed. No tools are available in Norway for penicillin delabeling outside an allergy clinic.

Objective

To create and validate the first penicillin delabeling pathway applicable outside an allergy clinic in Norway.

Methods

An interdisciplinary taskforce created a penicillin allergy delabeling program (PAD) adapted to the Norwegian health care system. This was validated in a prospective, single-center study. Very low-risk and low-risk patients underwent a direct oral penicillin challenge and high-risk patients were referred for allergologic evaluation.

Results

One-hundred forty-nine patients declaring penicillin allergy were included. Seventy-four (50%) were very-low- and low risk patients suitable for a direct oral penicillin challenge resulting in only 1 mild reaction. Sixty high-risk patients were eligible for an oral penicillin challenge after allergologic evaluation; 3 patients reacted non-severely.

Conclusion

We have created and demonstrated feasibility of the first penicillin delabeling program (PAD) applicable in a hospital setting outside an allergy clinic in Norway. Our data suggest this is safe and beneficial, with 49% patients delabeled through a direct oral penicillin challenge, performed without any serious adverse events, and an overall 87% delabeling rate.

Drug Allergy Alert System in a Spanish University Hospital: Description and Dynamics of Use

INTRODUCTION

The drug allergy alert system reduces the frequency of adverse drug events, although it is subjected to collateral effects, since 80-90% of alerts are not real, and a large percentage of alerts are overridden (46.2-96.2%). We reviewed how the alert system is used at University Hospital Fundación Alcorcon (HUFA).

METHODS

Data were obtained from the drug allergy alert and the alert overriding notification forms (both in the period 2011-20). We also recorded drug allergy diagnoses at HUFA, drug consumption in primary care in 2016. We calculated the incidence of drug allergy alert activation, temporal trends in use, and correlations between the number of drugs in several datasets.

RESULTS

We collected 15,535 alerts. NSAIDs and penicillins were the drugs with the highest number of drug allergy alerts (36.55% and 26.91%, respectively). A correlation was found between the number of drug alerts and the type of drug allergy in HUFA in 2016. Only 6.83% of the alerts were removed, and, of these, 21.77% were reactivated. Approximately 100 overrides were recorded per year from 2016 (6.8% of 8,434 activated alerts during 2014-2020).

CONCLUSIONS

The number of drug allergy alerts recorded via the drug allergy alert system of HUFA correlates with the distribution of drug allergy diagnoses in the hospital, although many of the alerts could be false positives (as per current published evidence). We detected a very low frequency of removed alerts (6.83%), a relevant frequency of reactivations (one quarter), and a very low frequency of overrides (6.8%).

Analysis of a clinical guideline for treatment and early discharge in complicated acute appendicitis

OBJECTIVE

The objective of this study was to assess the results of a clinical guideline for the treatment and early discharge of patients with complicated acute appendicitis in terms of infectious complications and hospital stay.

MATERIALS AND METHODS

A guideline for appendicitis treatment according to severity was created. Complicated appendicitis cases were treated with ceftriaxone-metronidazole for 48h, with discharge being approved if certain clinical and blood test criteria were met. A retrospective analytical study comparing the incidence of postoperative intra-abdominal abscess (IAA) and surgical site infection (SSI) in patients under 14 years of age to whom the new guideline was applied (Group A) vs. the historical cohort (Group B, treated with gentamicin-metronidazole for 5 days) was carried out. A prospective cohort study to assess which antibiotic therapy (amoxicillin-clavulanic acid or cefuroxime-metronidazole) proved more effective in patients meeting early discharge criteria was also conducted.

RESULTS

205 patients under 14 years of age were included in Group A, whereas 109 patients were included in Group B. IAA was present in 14.3% of patients from Group A vs. 13.8% from Group B (p= 0.83), while SSI was present in 1.9% of patients from Group A vs. 8.25% from Group B (p= 0.008). Early discharge criteria were met by 62.7% of patients from Group A. Median hospital stay decreased from 6 to 3 days. At discharge, 57% of patients received amoxicillin-clavulanic acid, whereas 43% received cefuroxime-metronidazole, with no differences being found in terms of SSI (p= 0.24) or IAA (p= 0.12).

CONCLUSIONS

Early discharge reduces hospital stay without increasing the risk of postoperative infectious complications. Amoxicillin-clavulanic acid is a safe option for at-home oral antibiotic therapy.

Optimizing Cefazolin Prophylaxis in Obstetrical Patients with Reported Beta-Lactam Allergy Undergoing Cesarean Delivery

OBJECTIVE

Evaluate the impact of an allergy history guided algorithm for optimizing peri-operative cefazolin use in patients with reported beta-lactam allergy undergoing cesarean delivery.

METHODS

The Allergy Clarification for Cefazolin Evidence-based Prescribing Tool (ACCEPT) was developed through consensus by allergists, anesthesiologists and infectious diseases specialists, and implemented over a two-month period (December 1, 2018 to January 31, 2019). A segmented regression on monthly cefazolin use was conducted during the baseline (January 1 to November 30, 2018) and intervention (February 1 to December 31, 2019) periods to evaluate the impact of ACCEPT on the monthly use of peri-operative cefazolin in patients with reported beta-lactam allergy undergoing cesarean delivery. The frequency of peri-operative allergic reactions and surgical site infections were collected during both periods.

RESULTS

Of the 3128 eligible women who underwent a cesarean delivery, 282 (9%) reported a beta-lactam allergy. The most common beta-lactam allergens were penicillin (64.3%), amoxicillin (16.0%), and cefaclor (6.0%). The most frequently reported allergic reactions were rash (38.1%), hives (21.4%), and unknown (11.6%). Use of cefazolin increased from 52% (baseline) to 87% during the intervention period. Segmented regression analysis confirmed a statistically significant increase following implementation (incidence rate ratio 1.62, 95% CI 1.19 - 2.21, p=0.002). There was one perioperative allergic reaction in the baseline period and two during the intervention period. Cefazolin use remained high (92%) two years after algorithm implementation.

CONCLUSIONS

Implementation of a simple allergy history guided algorithm in obstetrical patients with reported beta-lactam allergy resulted in a sustained increase in peri-operative cefazolin prophylaxis.

Novel Penicillin Derivatives Against Selected Multiple-Drug Resistant Bacterial Strains: Design, Synthesis, Structural Analysis, in silico and in Vitro Studies

INTRODUCTION

The rising numbers of multiple drug-resistant (MDR) pathogens and the consequent antibacterial therapy failure that resulted in severe medical conditions push to illustrate new molecules with extended activity against the resistant strains. In this manner, chemical derivatization of known antibiotics is proposed to save efforts in drug discovery, and penicillins serve as an ideal in this regard.

METHOD

Seven synthesized 6-aminopenicillanic acid-imine derivatives (2a-g) were structure elucidated using FT-IR, 1H NMR, 13C NMR, and MS spectroscopy. In silico molecular docking and ADMET studies were made. The analyzed compounds obeyed Lipinski's rule of five and showed promising in vitro bactericidal potential when assayed against E. coli, E. cloacae, P. aeruginosa, S. aureus, and A. baumannii. MDR strains using disc diffusion and microplate dilution techniques.

RESULT

The MIC values were 8 to 32 µg/mL with more potency than ampicillin, explained by better membrane penetration and more ligand-protein binding capacity. The 2g entity was active against E. coli. This study was designed to find new active penicillin derivatives against MDR pathogens.

CONCLUSION

The products showed antibacterial activity against selected MDR species and good PHK, PHD properties, and low predicted toxicity, offering them as future candidates that require further preclinical assays.

The Combined Use of Chronological and Morphological Criteria in the Evaluation of Immediate Penicillin Reactions: Evidence From a Large Study

BACKGROUND

Immediate hypersensitivity reactions to penicillins are often labeled on the basis of a similar set of symptoms, but a key feature of these reactions that can be reproduced in diagnostic testing may be the timing of a reaction in relation to the dose administration.

OBJECTIVE

To determine whether the timing of a reaction in response to the last dose of a penicillin would predict the results of diagnostic testing.

METHODS

We evaluated 1074 patients by performing skin tests, serum specific IgE assays (ImmunoCAP), and challenges. Patients who were evaluated by us more than 6 months after their reactions and found negative were reevaluated within 2 to 4 weeks.

RESULTS

Patients who had reacted within 1 hour after the first dose, within 1 hour after subsequent doses, more than 1 hour to within 6 hours after the first dose, or more than 1 hour to within 6 hours after subsequent doses were classified as group A (758 individuals), B (92), C (67), or D (157), respectively. Penicillin hypersensitivity was diagnosed in 707 patients (65.8%) by skin tests (407 patients, 57.6%), ImmunoCAP (47, 6.6%), both tests (232, 32.8%), or challenges (21, 3%). A conversion to allergy-test positivity occurred in 7 of 10 patients with anaphylactic reactions and in 1 of 28 patients with other reactions who were reevaluated after negative challenges. The rate of penicillin-allergic patients in groups A, B, C, and D was 85%, 35.9%, 35.8%, and 3.8%, respectively. Only 1 of 107 patients reporting cutaneous reactions lasting more than 1 day had positive results to allergy tests.

CONCLUSIONS

IgE-mediated hypersensitivity can be diagnosed by skin tests in about 70% of subjects who react within 1 hour (eg, patients from groups A and B). This hypersensitivity can be lost over time, as demonstrated by the negativization of allergy tests in follow-up studies. In subjects with anaphylactic reactions, however, it is advisable to not consider this phenomenon definitive. In fact, a conversion to allergy test positivity can be observed in up to 20% of such subjects retested after negative challenges.

Top Myths of Diagnosis and Management of Infectious Diseases in Hospital Medicine

Antimicrobial agents are among the most frequently prescribed medications during hospitalization. However, approximately 30% to 50% or more of inpatient antimicrobial use is unnecessary or suboptimal. Herein, we describe 10 common myths of diagnosis and management that often occur in the hospital setting. Further, we discuss supporting data to dispel each of these myths. This analysis will provide hospitalists and other clinicians with a foundation for rational decision-making about antimicrobial use and support antimicrobial stewardship efforts at both the patient and institutional levels.

75% negative skin test results in patients with suspected hypersensitivity to beta-lactam antibiotics: Influencing factors and interpretation of test results

Background

The diagnostic approach for beta-lactam (BL) drug hypersensitivity reactions (DHR) is based on the history, clinical signs, skin tests (ST), in vitro tests, and drug provocation tests (DPT). The aim of this study was to assess the performance of an allergy workup with ST in a real-world use.

Methods

In this cross-sectional study the rate of positive ST in subjects with suspected DHR to penicillins and cephalosporins was investigated. Of special interest were correlations of ST positivity: 1) to the time intervals between index reaction and the allergic work-up, 2) time interval from drug exposure to the onset of signs, 3) pattern of manifestation in delayed DHR and involvement of test area in the index reaction, and 4) potential advantage of patch testing in delayed DHR.

Results

175 patients were included between January 2018 and April 2019 (63.4% female), 45 (25.7%) with immediate DHR manifestation and 130 with delayed DHR manifestation (74.3%). A total of 44 patients (25.1%) had a positive ST (immediate DHR 37.8% versus 20.0% in delayed DHR). ST positivity decreased in both groups after 3 years from 47.8% [95%CI 29.2-67] to 23.5% [95%CI 9.6-47.3] in immediate DHR and 23.0% [95%CI 15-4-32.9] to 12.9% [95%CI 5.1-28.9] in delayed DHR. The proportion of positive ST was higher in patients with more severe forms of delayed DHR, and in subjects with a shorter latency period of onset of symptoms after drug exposure: 0-3d: 29.5% [95%CI 19.6-41.9] vs. >3d: 11.6% [95%CI 6.0-21.2]). No sensitization was shown in delayed urticaria or angioedema. ST done outside the skin area involved during the index reaction were negative in all cases (0/38 vs. 26/84 in cases with involved area). The combination of patch test and intradermal test (IDT) revealed an additional positive result in 2/77 cases. Additional in vitro testing reduced the proportion of negative test results to 72%.

Conclusion

In most patients with negative test results, we could not clarify the cause of the BL-associated adverse events even with further investigations (including DPT). How to prevent new drug-induced adverse events in such patients has hardly been investigated yet. Corresponding cohort studies could improve the data situation.

Rapid and sensitive analytical method for the determination of amoxicillin and related compounds in water meeting the requirements of the European union watch list

The presence of antibiotics in the aquatic environment is becoming one of the main research focus of scientists and policy makers. Proof of that is the inclusion of four antibiotics, amongst which is amoxicillin, in the EU Watch List (WL) (Decision 2020/1161/EU)) of substances for water monitoring. The accurate quantification of amoxicillin in water at the sub-ppb levels required by the WL is troublesome due to its physicochemical properties. In this work, the analytical challenges related to the determination of amoxicillin, and six related penicillins (ampicillin, cloxacillin, dicloxacillin, penicillin G, penicillin V and oxacillin), have been carefully addressed, including sample treatment, sample stability, chromatographic analysis and mass spectrometric detection by triple quadrupole. Given the low recoveries obtained using different solid-phase extraction cartridges, we applied the direct injection of water samples using a reversed-phase chromatographic column that allowed working with 100% aqueous mobile phase. Matrix effects were evaluated and corrected using the isotopically labelled internal standard or correction factors based on signal suppression observed in the analysis of spiked samples. The methodology developed was satisfactorily validated at 50 and 500 ng L ^- 1 for the seven penicillins studied, and it was applied to different types of water matrices, revealing the presence of ampicillin in one surface water sample and cloxacillin in three effluent wastewater samples.

Effects of piperacillin/tazobactam or cefepime on folinate dose in patients receiving high-dose methotrexate: A retrospective cohort study using Japanese administrative claims data

INTRODUCTION

Delayed methotrexate (MTX) clearance with the co-administration of piperacillin/tazobactam (PIPC/TAZ) has been reported. Penicillins have been associated with reduced MTX clearance but the evidence is limited. There are no cases described with cefepime but penicillins are listed as interacting with MTX. We aimed to reveal whether the co-administration of PIPC/TAZ or CFPM affects MTX clearance using data from an administrative database.

METHODS

We used data from the JMDC database, a large insurance claims database constructed in Japan. We included patients who were prescribed PIPC/TAZ or CFPM between days 1 and 3 in high-dose MTX (HD-MTX). We compared one co-administration episode (with PIPC/TAZ or CFPM) to one control episode (without), as a match-control study of two different episodes in the same patient. The primary outcomes were the duration and cumulative dose of leucovorin (LV) as a surrogate indicator of delayed MTX clearance.

RESULTS

Three patients who were co-administered PIPC/TAZ and 16 patients who were co-administered CFPM with HD-MTX were included. In the PIPC/TAZ group, the duration and the cumulative doses of LV were similar in co-administration and control episode (median 3.0 vs. 3.0 days and 288.0 vs. 219.0 mg). In the CFPM group, the duration and the cumulative doses of LV were not significantly different in co-administration and control episode (3.0 vs. 4.0 days and 169.5 vs. 258.0 mg).

CONCLUSIONS

Our findings revealed that PIPC/TAZ did not necessarily cause a delay in MTX clearance during HD-MTX therapy. Moreover, the co-administration of CFPM with HD-MTX did not affect MTX clearance.

Outcomes in reported penicillin allergic mothers and neonates requiring Group B streptococcal prophylaxis: a retrospective observational cohort study

Background

Infectious morbidity and mortality in the first week of life is commonly caused by early-onset neonatal Group B streptococcus (GBS) disease. This infection is spread from GBS positive mothers to neonates by vertical transmission during delivery and results in serious illness for newborns. Intrapartum prophylactic antibiotics have decreased the incidence of early-onset neonatal GBS disease by 80%. Patients labeled with a penicillin allergy (PcnA) alternatively receive either vancomycin or clindamycin but effectiveness is controversial. We evaluated the influence of a reported PcnA label versus no PcnA label on inpatient maternal and neonatal outcomes.

Methods

Our goal was to examine the relationship between a PcnA label, maternal and neonatal outcomes, and hospital costs. We collected retrospective data with institutional IRB approval from 2016 – 2018 for hospitalized patients who were GBS positive, pregnant at time of admission, ≥ 18 years of age, received antibiotic prophylaxis for GBS, were labeled as PcnA or non-PcnA, and completed a vaginal delivery. Patient characteristics and maternal/neonatal outcomes were examined. Statistical tests included calculations of means, medians, proportions, Mann–Whitney, two-sample t-tests, Chi-squared or Fisher’s Exact tests, and generalized linear and logistic regression models. Significance was set at p < 0.05.

Results

Most PcnA patients were white, older, had a higher median body mass index and mean heart rate, and a greater proportion used tobacco than non-PcnA patients. In regression analyses, PcnA hospitalized patients received a shorter duration of antibiotic treatment than non-PcnA patients [incidence rate ratio (IRR): 0.45, 95% CI: 0.38–0.53]. PcnA patients were also more likely to have their baby’s hospital LOS be > 48 h [adjusted odds ratio (AOR): 1.35, 95% CI: 1.07–1.69] even though the PcnA mothers’ LOS was not different from non-PcnA mothers. Cost of care, mortality, intensive care, median parity, mean gravidity, and miscarriage were similar between the groups.

Conclusions

In hospitalized obstetric patients, a PcnA label was associated with a shorter maternal course of antibiotic treatment and a longer neonatal LOS. Further prospective studies are needed to clarify the underlying reasons for these outcomes.

Biodegradation pathway of penicillins by β-lactamase encapsulated in metal-organic frameworks

The pollution caused by the abuse of antibiotics has posed a serious threat to the ecological environment and human health, so development of effective strategies for degradation and disposal of antibiotic residues is urgently needed. In this work, penicillinase, a kind of β-lactamase, was immobilized into zeolitic imidazolate framework-8 (ZIF-8) by self-assembly method and the catalytic performance of the β-lactamase@ZIF-8 porous materials for degradation of penicillins has been investigated by high performance liquid chromatography coupled with mass spectrometry. The results illustrated that the catalytic activity of the encapsulated enzyme was significantly enhanced comparing with that of free enzyme. Meanwhile, the β-lactamase@ZIF-8 exhibited excellent stability under denaturing conditions including high temperature, organic solvent and the enzyme inhibitor. The catalytic degradation mechanism of the β-lactamase@ZIF-8 for penicillins has been probed and verified, and it has been found that the Zn (II) ion on ZIF-8 frameworks could form the complex with the target molecule, which weakened the bond of the four-membered β-lactam ring in the penicillin molecule, and thus enhanced the degradation efficiency of the enzyme. This work provided a promising strategy for eliminating the penicillin residues in water environment.

Antibiotics in treatment of peritonsillar infection: clindamycin versus penicillin

OBJECTIVE

This study aimed to compare antibiotic treatment with clindamycin versus penicillin V or G in terms of time to recovery and recurrence in patients with peritonsillar infection, including both peritonsillar cellulitis and peritonsillar abscess.

METHOD

This retrospective cohort study examined the records of 296 patients diagnosed with peritonsillar infection. Based on the ENT doctor's choice of antibiotics, patients were divided into clindamycin and penicillin groups.

RESULTS

Mean number of days in follow up was 3.5 days in the clindamycin group and 3.4 days in the penicillin group. The recurrence rate within 2 months was 7 per cent in the clindamycin group and 4 per cent in the penicillin group.

CONCLUSION

This study found no significant differences in either recovery or recurrence between the groups. This supports the use of penicillin as a first-line treatment, considering the greater frequency of adverse effects of clindamycin shown in previous studies, as well as its profound collateral damage on the intestinal microbiota, resulting in antibiotic resistance.

Piperacillin-Tazobactam Hypersensitivity: A Large, Multicenter Analysis

BACKGROUND

Piperacillin/tazobactam is a broad-spectrum penicillin. Hypersensitivity reactions are less commonly reported than with other penicillins except in patients with cystic fibrosis.

OBJECTIVE

Detailed clinical characterization of a patient cohort referred with suspected piperacillin-tazobactam hypersensitivity.

METHODS

Retrospective analysis of the demographic characteristics, clinical presentation, investigation, and management of 87 patients presenting to 5 European allergy centers. Patients underwent skin prick and intradermal testing with piperacillin/tazobactam, major (penicilloyl-polylysine) and minor (sodium penilloate) determinants, amoxicillin, benzylpenicillin, flucloxacillin, co-amoxiclav, clavulanic acid, and meropenem with immediate and, where appropriate, delayed reading of tests. Skin test-negative patients underwent drug provocation to piperacillin/tazobactam and/or other penicillins. A multistep protocol was used, depending on risk assessment.

RESULTS

Forty-eight of 87 (55%) patients were diagnosed with hypersensitivity to piperacillin/tazobactam with either positive skin or drug provocation test results, of whom 10 (21%) had a diagnosis of cystic fibrosis. Twenty-six (54%) patients presented with immediate and 22 (45%) with nonimmediate hypersensitivity. Patients with cystic fibrosis predominantly presented with nonimmediate hypersensitivity (70%). Reactions were severe in 52% of immediate reactors (Brown's anaphylaxis grade 3) and moderately severe (systemic involvement) in 75% of nonimmediate reactors. The number of patients with negative skin test results tolerating reintroduction was comparable in immediate (80%) and nonimmediate (88%) hypersensitivity. One-third of patients were cross-sensitized to other penicillins. The cross-sensitization pattern raised the possibility of tazobactam allergy in 3 patients. In 21 patients selectively sensitized to piperacillin/tazobactam (12 immediate, 9 nonimmediate), tolerance to other beta-lactams was demonstrated by drug provocation testing.

CONCLUSIONS

Piperacillin-tazobactam caused immediate and nonimmediate hypersensitivity with similar frequency. Most patients were selectively sensitized and tolerated other penicillins. Some patients may be allergic to the beta-lactamase inhibitor only.

Ampicillin sodium: Isolation, identification and synthesis of the last unknown impurity after 60 years of clinical use

Ampicillin, discovered in 1958, was the first broad spectrum semisynthetic penicillin introduced into the market. Despite its wide use not all the impurities have been identified to date. Herein, the last unknown impurity present in commercially available medicines was isolated and identified. This impurity that accounts up to 0.8 in area % by HPLC (EP 10.0) in the Reference Listed Drugs (RLD) was characterized and identified to be the 16-keto penicillin G. The structure was confirmed by comparison with a chemically synthesized sample. The determination of the Relative Response Factor (RRF) of the impurity respect to the parent drug allowed to recalculate the real amount that is consistently below the reporting threshold.

Diagnostic procedures & practices in drug allergy/hypersensitivity: a survey of 13 Asian countries

BACKGROUND

The issues and challenges in the diagnosis of drug allergy/hypersensitivity among children and adults in Asia are likely to be different from non-Asian countries.

OBJECTIVE

To study the diagnostic modalities used in the evaluation and management of drug allergy/drug hypersensitivity reactions (DHRs) among member societies of the Asia Pacific Association of Allergy, Asthma and Clinical Immunology (APAAACI).

METHODS

A questionnaire comprising 41 questions was circulated electronically to member societies and individual members of APAAACI between January 23, 2020 and March 6, 2020.

RESULTS

Twenty-six respondents from 15 member societies and 1 individual member responded. European DHR guidelines were most commonly used. Skin prick and intradermal testing was used by 100%, with only 60% having access to commercial penicillin skin test reagents. In vitro-specific IgE tests were used by 75%, and basophil activation test by 56.3% for immediate DHR. Patch tests were used by 75% in contrast to lymphocyte transformation tests by 25% for nonimmediate DHR. Drug provocation tests were used by 68.8%, the most common indication being to exclude hypersensitivity where history/symptoms were not suggestive of drug hypersensitivity/allergy (93.3%). Human leukocyte antigen (HLA) genotype testing was mandatory among 25% respondents before new carbamazepine prescriptions, and 8.3% for allopurinol prescriptions.

CONCLUSIONS

There was increased use of skin testing for iodinated contrast media hypersensitivity and patch testing for nonimmediate DHR. HLA genotype testing prior to new carbamazepine, allopurinol and abacavir prescriptions remain variable despite strong associations for severe cutaneous adverse reactions with Asian ethnicity. Results of this survey form a useful framework for developing educational and training needs and for improving access to drug allergy diagnostic and treatment modalities across APAAACI member societies.

Validation and clinical application of a multiplex high performance liquid chromatography - tandem mass spectrometry assay for the monitoring of plasma concentrations of 12 antibiotics in patients with severe bacterial infections

OBJECTIVE

Unpredictable pharmacokinetics of antibiotics in patients with life-threatening bacterial infections is associated with drug under- or overdosing. Therapeutic drug monitoring (TDM) may guide dosing adjustment aimed at maximizing antibacterial efficacy and minimizing toxicity. Rapid and accurate analytical methods are key for real-time TDM. Our objective was to develop a robust high-performance liquid chromatography-tandem mass spectrometry method (HPLC-MS/MS) for multiplex quantification of plasma concentrations of 12 antibiotics: imipenem/cilastatin, meropenem, ertapenem, cefepime, ceftazidime, ceftriaxone, piperacillin/tazobactam, amoxicillin, flucloxacillin, rifampicin, daptomycin.

METHODS

A single extraction procedure consisting in methanol plasma protein precipitation and H₂O dilution was used for all analytes. After chromatographic separation on an Acquity UPLC HSS-T3 2.1 × 50 mm, 1.8 µm (Waters®) column, quantification was performed by electro-spray ionisation-triple quadrupole mass spectrometry with selected reaction monitoring detection. Antibiotics were divided in two pools of calibration according to the frequency of analyses requests in the hospital routine antibiotic TDM program. Stable isotopically-labelled analogues were used as internal standards. A single analytical run lasted less than 9 min.

RESULTS

The method was validated based on FDA recommendations, including assessment of extraction yield (96-113.8%), matrix effects, and analytical recovery (86.3-99.6%). The method was sensitive (lower limits of quantification 0.02-0.5 µg/mL), accurate (intra/inter-assay bias -11.3 to +12.7%) and precise (intra/inter-assay CVs 2.1-11.5%) over the clinically relevant plasma concentration ranges (upper limits of quantification 20-160 µg/mL). The application of the TDM assay was illustrated with clinical cases that highlight the impact on patients' management of an analytical assay providing information with short turn-around time on antibiotic plasma concentration.

CONCLUSION

This simple, robust high-throughput multiplex HPLC-MS/MS assay for simultaneous quantification of plasma concentrations of 12 daily used antibiotics is optimally suited for clinically efficient real-time TDM.

Transport systems, intracellular traffic of intermediates and secretion of β-lactam antibiotics in fungi

Fungal secondary metabolites are synthesized by complex biosynthetic pathways catalized by enzymes located in different subcellular compartments, thus requiring traffic of precursors and intermediates between them. The β-lactam antibiotics penicillin and cephalosporin C serve as an excellent model to understand the molecular mechanisms that control the subcellular localization of secondary metabolites biosynthetic enzymes. Optimal functioning of the β-lactam biosynthetic enzymes relies on a sophisticated temporal and spatial organization of the enzymes, the intermediates and the final products. The first and second enzymes of the penicillin pathway, ACV synthetase and IPN synthase, in Penicillium chrysogenum and Aspergillus nidulans are cytosolic. In contrast, the last two enzymes of the penicillin pathway, phenylacetyl-CoA ligase and isopenicillin N acyltransferase, are located in peroxisomes working as a tandem at their optimal pH that coincides with the peroxisomes pH. Two MFS transporters, PenM and PaaT have been found to be involved in the import of the intermediates isopenicillin N and phenylacetic acid, respectively, into peroxisomes. Similar compartmentalization of intermediates occurs in Acremonium chrysogenum; two enzymes isopenicillin N-CoA ligase and isopenicillin N-CoA epimerase, that catalyse the conversion of isopenicillin N in penicillin N, are located in peroxisomes. Two genes encoding MFS transporters, cefP and cefM, are located in the early cephalosporin gene cluster. These transporters have been localized in peroxisomes by confocal fluorescence microscopy. A third gene of A. chrysogenum, cefT, encodes an MFS protein, located in the cell membrane involved in the secretion of cephalosporin C, although cefT-disrupted mutants are still able to export cephalosporin by redundant transporters. The secretion of penicillin from peroxisomes to the extracellular medium is still unclear. Attempts have been made to identify a gene encoding the penicillin secretion protein among the 48 ABC-transporters of P. chrysogenum. The highly efficient secretion system that exports penicillin against a concentration gradient may involve active penicillin extrusion systems mediated by vesicles that fuse to the cell membrane. However, there is no correlation of pexophagy with penicillin or cephalosporin formation since inactivation of pexophagy leads to increased penicillin or cephalosporin biosynthesis due to preservation of peroxisomes. The penicillin biosynthesis finding shows that in order to increase biosynthesis of novel secondary metabolites it is essential to adequately target enzymes to organelles.

The relation between prescribing of different antibiotics and rates of mortality with sepsis in US adults

BACKGROUND

Antibiotic use contributes to the rates of sepsis and the associated mortality, particularly through lack of clearance of resistant infections following antibiotic treatment. At the same time, there is limited information on the effects of prescribing of some antibiotics vs. others on subsequent sepsis and sepsis-related mortality.

METHODS

We used a multivariable mixed-effects model to relate state-specific rates of outpatient prescribing overall for oral fluoroquinolones, penicillins, macrolides, and cephalosporins between 2014 and 2015 to state-specific rates of mortality with sepsis (ICD-10 codes A40-41 present as either underlying or contributing causes of death on a death certificate) in different age groups of US adults between 2014 and 2015, adjusting for additional covariates and random effects associated with the ten US Health and Human Services (HHS) regions.

RESULTS

Increase in the rate of prescribing of oral penicillins by 1 annual dose per 1000 state residents was associated with increases in annual rates of mortality with sepsis of 0.95 (95% CI (0.02,1.88)) per 100,000 persons aged 75-84y, and of 2.97 (0.72,5.22) per 100,000 persons aged 85 + y. Additionally, the percent of individuals aged 50-64y lacking health insurance, as well as the percent of individuals aged 65-84y who are African-American were associated with rates of mortality with sepsis in the corresponding age groups.

CONCLUSIONS

Our results suggest that prescribing of penicillins is associated with rates of mortality with sepsis in older US adults. Those results, as well as the related epidemiological data suggest that replacement of certain antibiotics, particularly penicillins in the treatment of different syndromes should be considered with the aim of reducing the rates of severe outcomes, including mortality related to bacterial infections.

Empirical fluoroquinolones versus broad-spectrum beta-lactams for Gram-negative bloodstream infections in the absence of antimicrobial resistance risk factors

OBJECTIVES

Increasing antimicrobial resistance rates limit empirical antimicrobial treatment options for Gram-negative bloodstream infections (GN-BSI). However, antimicrobial resistance may be predicted based on patient-specific risk factors using precision medicine concepts. This retrospective, 1:2 matched cohort examined clinical outcomes in hospitalized adults without major risk factors for antimicrobial resistance receiving empirical fluoroquinolones or broad-spectrum beta-lactams (BSBL) for GN-BSI at Prisma Health-Midlands hospitals in Columbia, SC, USA from January 2010 through June 2015.

METHODS

Multivariable logistic regression was used to examine early treatment failure at 72-96 h from GN-BSI. Cox proportional hazards regression was used to examine 28-day mortality and hospital length of stay (HLOS).

RESULTS

Among 74 and 148 patients receiving empirical fluoroquinolones and BSBL for GN-BSI, respectively, median age was 68 years, 159 (72%) were women, and 152 (68%) had a urinary source of infection. Early treatment failure rates were comparable in fluoroquinolone and BSBL groups (27% vs. 30%, respectively, odds ratio 0.82, 95% confidence intervals [CI] 0.43-1.54, P = 0.53), as well as 28-day mortality (8.9% vs. 9.7%, respectively, hazards ratio [HR] 0.74, 95% CI 0.26-1.90, P = 0.54). Median HLOS was 6.1 days in the fluoroquinolone group and 7.1 days in the BSBL group (HR 0.73, 95% CI 0.54-0.99, P = 0.04). Transition from intravenous to oral therapy occurred sooner in the fluoroquinolone group than in the BSBL group (3.0 vs. 4.9 days, P < 0.001).

CONCLUSIONS

In the absence of antimicrobial resistance risk factors, fluoroquinolones provide an additional empirical treatment option to BSBL for GN-BSI. Shorter HLOS in the fluoroquinolone group may be due to earlier transition from intravenous to oral antimicrobial therapy.

Cefazolin Versus Anti-Staphylococcal Penicillins for the Treatment of Patients with Methicillin-Susceptible Staphylococcus aureus Infection: A Meta-Analysis with Trial Sequential Analysis

INTRODUCTION

Methicillin-susceptible Staphylococcus aureus (MSSA) is a common cause of infection in humans. Beta-lactam antibiotics are the preferred agents, with anti-staphylococcal penicillins (ASPs) or the first-generation cephalosporin, cefazolin, favored by clinicians. Recent studies comparing the two strategies suggest similar outcomes between the agents. The purpose of this meta-analysis was to explore differences between cefazolin and ASPs for the treatment of MSSA infections.

METHODS

We performed a meta-analysis with trial sequential analysis (TSA) of observational or cohort studies using a random-effects model. Two blinded reviewers independently assessed studies for inclusion, risk of bias, and data extraction. The primary outcome was all-cause mortality. Secondary outcomes included clinical failure, infection recurrence, and antibiotic discontinuation due to adverse events. Subgroup analyses were conducted for the primary outcome by type of ASP, studies with a high percentage of deep-seated infections, and studies of low to moderate risk of bias.

RESULTS

After performing a comprehensive search of the literature, and screening for study inclusion, 19 studies (13,390 patients) were included in the final meta-analysis. Fifteen of the 19 studies (79%) were judged as having a low or moderate risk of bias. Use of cefazolin was associated with lower all-cause mortality [odds ratio (OR) 0.71, 95% confidence interval (CI) 0.56-0.91, p = 0.006, I2 = 28%], clinical failure (OR 0.55, 95% CI 0.41-0.74, p < 0.001, I2 = 0%), and antibiotic discontinuation due to adverse events (OR 0.25, 95% CI 0.16-0.39, p < 0.001, I2 = 23%). Infection recurrence was higher in the cefazolin patients (OR 1.41, 95% CI 1.04-1.93, p = 0.03, I2 = 0%).

CONCLUSION

This meta-analysis demonstrated that the use of cefazolin was associated with significant reductions in all-cause mortality, clinical failure, and discontinuation due to adverse events, but was associated with an increased risk of infection recurrence.

FUNDING

University of Florida Open Access Publishing Fund funded the Rapid Service Fees.

TRIAL REGISTRATION

PROSPERO International Prospective Register of Systematic Reviews (study ID: CRD42018106442).

Beta-lactam allergy in Chinese patients and factors predicting genuine allergy

Introduction

Beta-lactams (BL) are the most frequently reported drug allergy, but the vast majority of patients are found not to be genuinely allergic after evaluation. Few studies have investigated the clinical predictors of genuine BL allergy, and the prevalence in hospitalized Chinese patients is unknown.

Methods

Patients admitted to a tertiary hospital in Hong Kong (HK) were analyzed to identify the prevalence and factors associated with the presence of BL allergy labels among hospitalized Chinese patients. A combined cohort of patients having completed allergy investigation for suspected BL allergies in the United Kingdom (UK) and HK were analyzed to identify predictors of genuine allergy.

Results

The prevalence of BL allergy labels in hospitalized HK Chinese was 5%, which was associated with female gender and concomitant non-BL antibiotic allergy labels. The rate of genuine BL allergy patients referred for suspected allergies in the UK and HK cohort was only 14%. History of anaphylaxis and interval of less than a year since the index reaction were independent clinical predictors of genuine BL allergy. The negative predictive value of penicillin skin testing was 90%, confirming the need for drug provocation testing after negative skin testing. There was a high rate of confirmed piperacillin-tazobactam allergy.

Discussion

The estimated true prevalence of genuine BL allergy in hospitalized HK Chinese is around 0.5%. This high rate of BL mislabeling highlights the need for comprehensive allergy evaluation and screening. History of anaphylaxis and duration since the index reaction are important predictors of genuine allergy. Piperacillin-tazobactam allergy may pose a unique challenge in this population with a high prevalence of suspected allergies, surging antibiotic resistance, and lack of testing available.

Levels of outpatient prescribing for four major antibiotic classes and rates of septicemia hospitalization in adults in different US states - a statistical analysis

BACKGROUND

Rates of sepsis/septicemia hospitalization in the US have risen significantly during recent years. Antibiotic resistance and use may contribute to those rates through various mechanisms, including lack of clearance of resistant infections following antibiotic treatment, with some of those infections subsequently devolving into sepsis. At the same time, there is limited information on the effect of prescribing of certain antibiotics vs. others on the rates of septicemia and sepsis-related hospitalizations and mortality.

METHODS

We used multivariable linear regression to relate state-specific rates of outpatient prescribing overall for oral fluoroquinolones, penicillins, macrolides, and cephalosporins between 2011 and 2012 to state-specific rates of septicemia hospitalization (ICD-9 codes 038.xx present anywhere on a discharge diagnosis) in each of the following age groups of adults: (18-49y, 50-64y, 65-74y, 75-84y, 85 + y) reported to the Healthcare Cost and Utilization Project (HCUP) between 2011 and 2012, adjusting for additional covariates, and random effects associated with the ten US Health and Human Services (HHS) regions.

RESULTS

Increase in the rate of prescribing of oral penicillins by 1 annual dose per 1000 state residents was associated with increases in annual septicemia hospitalization rates of 0.19 (95% CI (0.02,0.37)) per 10,000 persons aged 50-64y, of 0.48(0.12,0.84) per 10,000 persons aged 65-74y, and of 0.81(0.17,1.40) per 10,000 persons aged 74-84y. Increase by 1 in the percent of African Americans among state residents in a given age group was associated with increases in annual septicemia hospitalization rates of 2.3(0.32,4.2) per 10,000 persons aged 75-84y, and of 5.3(1.1,9.5) per 10,000 persons aged over 85y. Average minimal daily temperature was positively associated with septicemia hospitalization rates in persons aged 18-49y, 50-64y, 75-84y and over 85y.

CONCLUSIONS

Our results suggest positive associations between the rates of prescribing for penicillins and the rates of hospitalization with septicemia in US adults aged 50-84y. Further studies are needed to better understand the potential effect of antibiotic replacement in the treatment of various syndromes, including the potential impact of the recent US FDA guidelines on restriction of fluoroquinolone use, as well as the potential effect of changes in the practices for prescribing of penicillins on the rates of sepsis-related hospitalization and mortality.

Knowledge, practice and attitudes regarding antibiotics use among Lebanese dentists

Objectives:

Explore antibiotic use, assess conformity with evidence-practice guidelines, and describe knowledge and attitudinal factors among Lebanese dentists.

Methods:

National cross-sectional telephonic survey, using a standardized questionnaire addressing demographic, educational and professional data, usual antibiotics prophylactic and curative prescription pattern and influential factors, knowledge concerning antibiotics use in selected patient-populations, and attitude regarding antimicrobial resistance. Analyses used descriptive statistics, and bivariate analysis to observe predictors of higher knowledge.

Results:

the overall response rate for the study was around 21%. 322 dentists participated. On average, 17.51% of consultations resulted in antibiotic use; previous antibiotic experience mostly influenced prescriptions (81.3%). Referral of pregnant and lactating women and cardiac patients, when antibiotics are needed, was high (26.9%, 28.5% and 79.4%, respectively). Macrolides were the dominant first-line antibiotics in penicillin allergy (47.4%). Penicillins were most common for pregnant and lactating women. Penicillins (95.0%), 2g (63.9%), and 1 hour pre-procedure (34%) were the main components of prophylaxis for cardiac patients. Prophylactic and curative use varied widely; few dentists exhibited guideline-conform prescriptions. Mean knowledge scores of prophylaxis for cardiac and non-cardiac patients, and antibiotics’ side effects were predominantly poor (46.75±14.82, 39.21±33.09 and 20.27±18.77, respectively over 100). Practicing outside Beirut, undergraduate qualification in Lebanon, and post-graduate qualification predicted higher knowledge. 75.9% acknowledged the contribution of dentistry-based prescribing to antibiotic resistance and 94.7% knew at least one cause of resistance.

Conclusions:

Dentists show positive attitude towards antimicrobial resistance. Yet, they lack uniformity in antibiotic stewardship. Poor knowledge and guideline-incongruent prophylactic and therapeutic prescribing are observed. Development of targeted interventions is needed to promote judicious antibiotic use within Lebanese dentistry.

Basophil Activation Test Application in Drug Hypersensitivity Diagnosis: An Empirical Approach

BACKGROUND

The diagnosis of drug hypersensitivity reactions (DHRs) is based both on clinical history and in vivo tests, such as specific IgE and cutaneous tests, when available.

OBJECTIVES

The aim of this work was to evaluate the basophil activation test (BAT) as a supplementary tool for drug challenges and drug allergy diagnosis.

METHOD

We evaluated 204 outpatients reporting DHRs. Available serum-specific IgE drugs were determined and cutaneous tests were performed when appropriate. BAT was performed immediately after blood sampling. The expression of CD63 was evaluated with flow cytometry. The test was considered positive when CD63 expression was > 5% and the stimulation index (the ratio of the percentage of CD63-expressing cells with drug exposure/percentage of CD63-expressing cells with wash buffer) was > 2. Patients who reported mild to severe reactions and those with a discrepancy between clinical history and BAT underwent a challenge test.

RESULTS

The drugs that caused adverse reactions were mainly antibiotics (49%). Non-steroid anti-inflammatory drugs (NSAID) were cited as responsible for DHRs in 37%, with the remaining 14% being due to other drugs. BAT revealed a high specificity (92%) and low sensitivity for antibiotics (40%). For the suspected reactions to penicillin, both the in vitro tests supported 94% of the diagnoses. We also observed a high specificity in the case of challenge with NSAIDs (100% specificity).

CONCLUSIONS

BAT is effective in discriminating adverse drug reactions, whilst only more critical cases require integrated evaluations and more complex clinical examinations. It is relevant that the concordance of anamnesis and in vitro tests reduce the need for challenge testing, limiting them to selected cases.

Hospitalizations in Children with a Penicillin Allergy Label: An Assessment of Healthcare Impact

BACKGROUND

Beta-lactam allergy is overdiagnosed. Diagnosis of penicillin allergy has been associated with a greater use of hospital resources and an increased risk of antibiotic-resistant infections, although this issue remains poorly studied in children. We aimed to compare patient characteristics and use of hospital resources in hospitalized children with and without a record of penicillin allergy.

METHODS

We identified all hospitalizations in children labelled as being allergic to penicillin in a database containing all hospitalizations in Portuguese public hospitals between 2000 and 2014, and compared these with a similar number of age-, sex-, and main diagnosis-matched hospitalizations without a penicillin allergy label. Comparisons were made for length of hospital stay, comorbidities (Charlson Comorbidity Index), in-hospital mortality, and hospitalization costs.

RESULTS

We identified 1,718 hospitalizations corresponding to children labelled as penicillin-allergic. Compared with patients without such a label, these children had longer hospital stays (mean 5 vs. 4 days, p = 0.03) and a higher comorbidity index (mean 0.11 vs. 0.09, p < 0.001). Hospitalization costs were also higher (EUR 2,071 vs. 1,798), but the difference was not significant (p = 0.12).

CONCLUSIONS

Hospitalizations of children labelled as allergic to penicillin are associated with longer hospital stays, more comorbidities, and a tendency towards higher hospitalization costs. An accurate diagnosis of penicillin allergy based on clinical history and confirmatory tests is therefore essential in all paediatric patients.

Cross-Reactivity and Tolerability of Cephalosporins in Patients with IgE-Mediated Hypersensitivity to Penicillins

BACKGROUND

Studies performed since 1990 on samples of at least 30 subjects with a documented IgE-mediated hypersensitivity to penicillins have found a rate of positive responses to allergy tests with cephalosporins ranging from 0% to 27%.

OBJECTIVE

We sought to assess the cross-reactivity with cephalosporins and evaluate the possibility of using cephalosporins in penicillin-allergic subjects.

METHODS

We conducted a prospective study of 252 consecutive subjects who had suffered 319 immediate reactions (mostly anaphylaxis) to penicillins and had positive skin tests to at least 1 penicillin reagent. All patients underwent serum specific IgE assays for cefaclor, as well as skin tests with 3 aminocephalosporins (cephalexin, cefaclor, and cefadroxil), cefamandole, cefuroxime, ceftazidime, ceftriaxone, cefotaxime, and cefepime. Patients with negative results for the last 5 cephalosporins were challenged with cefuroxime axetil and ceftriaxone; those with negative results for aminocephalosporins were also challenged with cefaclor and cefadroxil.

RESULTS

Ninety-nine participants (39.3%) had positive allergy tests for cephalosporins. Specifically, 95 (37.7%) were positive to aminocephalosporins and/or cefamandole, which share similar or identical side chains with penicillins. All 244 subjects who underwent challenges with cefuroxime axetil and ceftriaxone tolerated them. Of the 170 patients who underwent aminocephalosporin challenges, 3 reacted to cefaclor and 4 to cefadroxil.

CONCLUSIONS

Cross-reactivity between penicillins and cephalosporins seems to be mainly related to side chain similarity or identity. Subjects with an IgE-mediated hypersensitivity to penicillins could be treated with cephalosporins such as cefuroxime and ceftriaxone that have side-chain determinants different from those of penicillins and are negative in pretreatment skin testing.

Oxidation of β-lactam antibiotics by peracetic acid: Reaction kinetics, product and pathway evaluation

Peracetic acid (PAA) is a disinfection oxidant used in many industries including wastewater treatment. β-Lactams, a group of widely prescribed antibiotics, are frequently detected in wastewater effluents and surface waters. The reaction kinetics and transformation of seven β-lactams (cefalexin (CFX), cefadroxil (CFR), cefapirin (CFP), cephalothin (CFT), ampicillin (AMP), amoxicillin (AMX) and penicillin G (PG)) toward PAA were investigated to elucidate the behavior of β-lactams during PAA oxidation processes. The reaction follows second-order kinetics and is much faster at pH 5 and 7 than at pH 9 due to speciation of PAA. Reactivity to PAA follows the order of CFR ∼ CFX > AMP ∼ AMX > CFT ∼ CFP ∼ PG and is related to β-lactam's nucleophilicity. The thioether sulfur of β-lactams is attacked by PAA to generate sulfoxide products. Presence of the phenylglycinyl amino group on β-lactams can significantly influence electron distribution and the highest occupied molecular orbital (HOMO) location and energy in ways that enhance the reactivity to PAA. Reaction rate constants obtained in clean water matrix can be used to accurately model the decay of β-lactams by PAA in surface water matrix and only slightly overestimate the decay in wastewater matrix. Results of this study indicate that the oxidative transformation of β-lactams by PAA can be expected under appropriate wastewater treatment conditions.

Regional variation in antibiotic prescribing among medicare part D enrollees, 2013

Background

Antibiotics are among the most widely prescribed medications. The geographic variation in antibiotic prescribing patterns and associated costs among Medicare Part D recipients have not been described. The purpose of this study was to assess the regional variation in antibiotic prescriptions and costs among Medicare Part D enrollees in 2013.

Methods

Retrospective cohort review of all Medicare Part D enrollees in 2013, using the Medicare Provider Utilization and Payment Data: Part D Prescriber Public Use File. All original or refill prescription claims for antibiotics as listed in the Part D Prescriber Public Use File were included. Our primary outcomes were total antibiotic claims and antibiotic cost per Medicare Part D Enrollee. Data were analyzed descriptively by state and by geographic region as defined by the United States Census Bureau. Antibiotic claims were described overall and by antibiotic class.

Results

Over 54 million outpatient antibiotic claims were filed for Part D enrollees in 2013, representing more than $1.5 billion in total antibiotic expenditures. Antibiotic use was highest in the South (1,623 claims/1,000 enrollees), followed by the Midwest (1,401 claims/1,000 enrollees), Northeast (1,366 claims/1,000 enrollees), and West (1,292 claims/1,000 enrollees). Average antibiotic costs per enrollee in each region were as follows: South $46.58, Northeast $43.70, Midwest $40.54, and West $36.42. Fluoroquinolones were the most commonly prescribed class overall (12.2 million claims).

Conclusions

Antibiotic use among elderly Medicare enrollees in the United States was highest in the South region. Fluoroquinolones were the most common antibiotics used in all regions. These patterns could be utilized in the development of targeted antimicrobial stewardship efforts.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2091-0) contains supplementary material, which is available to authorized users.

Non-human Immunodeficiency Virus-related Ocular Syphilis in a Korean Population: Clinical Manifestations and Treatment Outcomes

Purpose

To describe the clinical manifestations and treatment outcomes of ocular syphilis in patients without human immunodeficiency virus (HIV) infection.

Methods

A total of 45 eyes from 39 patients with ocular syphilis confirmed by serologic tests were reviewed retrospectively. The included cases were all non-HIV-infected patients presenting with intraocular inflammation from 2002 to 2014 at Kyung Hee University Hospital. Medical records of 45 eyes were analyzed and included best-corrected visual acuity and ophthalmologic examination findings of the anterior and posterior segments to determine the focus of inflammation. Optical coherence tomography and fluorescein angiography findings as well as both medical and surgical management were also analyzed.

Results

The mean patient age was 61.0 years (range, 37 to 89 years). Bilateral ocular involvement occurred in 6 patients (15.4%), and diagnoses at presentation were most frequently related to posterior uveitis (38%), followed by panuveitis (29%) and optic neuritis (11%). Isolated interstitial keratitis and intermediate uveitis were uncommon (4%, both). Twenty-eight eyes (62.2%) were treated with penicillin, and 11 eyes (24.4%) underwent surgical treatment. The mean baseline best corrected visual acuity was 0.79 ± 0.59 (mean ± standard deviation, logarithm of the minimum angle of resolution) and significantly improved to 0.60 ± 0.63 at the final follow-up after treatment (p = 0.019). Mean visual improvement was significantly greater in the penicillin-treated group (p = 0.001). Visual impairment at the final visit occurred in 11 eyes (24.4%). Among the visual impairment group, 10 eyes (90.1%) had posterior segment-involving uveitis.

Conclusions

Visual outcomes of treated, non-HIV-related ocular syphilis were favorable regardless of time to presentation. Posterior segment-involving uveitis at presentation was associated with poor visual outcome.

Cross-Reactivity among Beta-Lactams

Penicillins and cephalosporins are the major classes of beta-lactam (BL) antibiotics in use today and one of the most frequent causes of hypersensitivity reactions to drugs. Monobactams, carbapenems, oxacephems, and beta-lactamase inhibitors constitute the four minor classes of BLs. This review takes into account mainly the prospective studies which evaluated cross-reactivity among BLs in subjects with a well-demonstrated hypersensitivity to a certain class of BLs by performing allergy tests with alternative BLs and, in case of negative results, administering them. In subjects with either IgE-mediated or T-cell-mediated hypersensitivity, cross-reactivity among BLs, particularly among penicillins and among cephalosporins, as well as between penicillins and cephalosporins, seems to be mainly related to structural similarities among their side-chain determinants. Specifically, in penicillin-allergic subjects, cross-reactivity between penicillins and cephalosporins may exceed 30% when they are administered cephalosporins with identical side chains to those of responsible penicillins. In these subjects, a few prospective studies have demonstrated a rate of cross-reactivity between penicillins and both carbapenems and aztreonam lower than 1%. With regard to subjects with an IgE-mediated hypersensitivity to cephalosporins, in a single study, about 25% of the 98 subjects with such hypersensitivity had positive results to penicillins, 3% to aztreonam, 2% to imipenem/cilastatin, and 1% to meropenem. The cross-reactivity related to the selective recognition of the BL ring by IgE or T lymphocytes, which entails positive responses to all BLs tested, appears to be exceptional. Some studies concerning cross-reactivity among BLs have found patterns of allergy-test positivity which cannot be explained by either the common BL ring or by similar or identical side chains, thus indicating the possibility of coexisting sensitivities to different BLs because of prior exposures to them.

Synergy between baicalein and penicillins against penicillinase-producing Staphylococcus aureus

The combination of baicalein (the active constituent of Scutellaria baicalensis) with penicillin G/amoxicillin showed potent synergy against 20 clinical penicillinase-producing Staphylococcus aureus strains including 10 isolates that were additionally methicillin-resistant (MRSA). The fractional inhibitory concentration (FIC) indices of penicillins+baiclein ranged from 0.14 to 0.38. Baicalein protected penicillins (penicillin G and amoxicillin) from penicillinase and increased the susceptibility of penicillinase-supplemented S. aureus ATCC 29213 in a dose-dependent manner. The inhibition of penicillinase activity by baicalein should be responsible for the synergism and protective effect. These findings offer us good evidence that the penicillins combined with baicalein showed potent synergistic activity against penicillinase-producing S. aureus and penicillinase-producing MRSA in vitro and might provide promising implications for clinical treatment of these bacterial infections.

Antistaphylococcal penicillins versus cephalosporins for definitive treatment of meticillin-susceptible Staphylococcus aureus bacteraemia: a systematic review and meta-analysis

The objective of this study was to assess the comparative effectiveness and safety of antistaphylococcal penicillins (ASPs) and cephalosporins for the definitive treatment of patients with meticillin-susceptible Staphylococcus aureus (MSSA) bacteraemia. PubMed and Scopus electronic databases were searched up to December 2013. All-cause mortality was the primary outcome of interest. A meta-analysis of unadjusted and adjusted data was performed. Seven articles (1643 patients) were included; all but one were retrospective studies, and three of them employed propensity score matching. The studies enrolled primarily adults hospitalised in medical wards for primary or secondary community-acquired, healthcare-associated or nosocomial MSSA bacteraemia. Several ASPs and cephalosporins were compared. Unadjusted 30-day mortality was lower in patients treated with ASPs than in those treated with cephalosporins [risk ratio (RR)=0.62, 95% confidence interval (CI) 0.40-0.98]. Propensity score-adjusted 30-day mortality was not different in patients receiving ASPs or cephalosporins (RR=0.75, 95% CI 0.41-1.39). Substantial heterogeneity and publication bias were found in these analyses. Both unadjusted (RR=0.85, 95% CI 0.54-1.32) and adjusted (RR=1.42, 95% CI 0.22-9.06) 90-day mortality did not differ between patients receiving ASPs or cephalosporins. Limited data regarding adverse events, development of resistance and recurrence were available. In conclusion, the limited available published data derive from retrospective studies and show that there appears to be no statistically significant difference in mortality between ASPs and cephalosporins for the treatment of MSSA bacteraemia.

Penicillin allergy evaluation: experience from a drug allergy clinic in an Arabian Gulf Country, Kuwait

BACKGROUND

Hypersensitivity to penicillin has been studied worldwide, but data regarding patterns of sensitization in Arabian Gulf countries are scarce.

OBJECTIVE

To describe the patterns of penicillin hypersensitivity during a 6-year study in Kuwait in terms of demographics, type of the culprit drug, in vivo and in vitro allergy testing.

METHODS

One hundred and twenty-four patients referred to the drug allergy clinic for penicillin allergy were fully evaluated by skin prick and intradermal testing. Drug provocation test was done on patients with negative results.

RESULTS

A total of 124 patients were evaluated for penicillin allergy. Mean age was 37.8 (standard deviation, 12.7) years, range from 8 to 74 years. Thirty-nine male (31.5%) and 85 female patients (68.5%) were included. Diagnosis of penicillin allergy was confirmed in 46 patients (37.1%). Among the 44 confirmed allergic patients by skin evaluation we had 15 (34.1%) positive skin prick test, and 29 (65.9%) positive intradermal testing. Among patients with positive skin testing, 47.7% were positive to major determinant benzylpenicilloyl poly-L-lysine, 20.4% to minor determinant mixture, 50.0% to penicillin G and 40.9% to ampicillin; 13.6% of patients were positive to amoxicillin by skin prick test. One patient had a positive radioallergosorbent test and one had a positive challenge test.

CONCLUSION

Penicillin allergy is a common problem with an incidence of about one third in our study subjects.

Thin layer chromatographic analysis of Beta-lactam antibiotics

PURPOSE

The paper describes some thin layer chromatographic procedures that allow simple and rapid separation and identification of penicillins and cephalosporins from complex mixtures.

METHODS

Using silicagel GF254 as stationary phase and selecting different mobile phases we succeeded in the separation of the studied beta-lactamins. Our aim was not only to develop a simple, rapid and efficient method for their separation but also the optimization of the analytical conditions.

RESULTS

No system will separate all the beta-lactams, but they could be identified when supplementary information is used from color reactions and/or by using additional chromatographic systems.

CONCLUSIONS

The right combination of solvent system and detection method allows the identification of the studied penicillins and cephalosporins and can be successfully used in the preliminary analysis beta-lactam antibiotics.

CONCLUSION

The right combination of solvent system and detection method allows the identification of the studied penicillins and cephalosporins and can be successfully used in the preliminary analysis beta-lactam antibiotics.

Simultaneous Determination and Identification of Penicillin Residues by High-Performance Liquid Chromatographic Analysis

A new method was developed for simultaneous determination and identification of seven penicillins (amoxicillin, ampicillin, methicillin, penicillin G, oxacillin, cloxacillin, and dicloxacillin) in bovine serum. Each sample was simply extracted with acetonitrile, and identification of the reaction products of penicillins after treatment with 1,2,4-triazole-HgCl₂ solution was then carried out by high-performance liquid chromatography (HPLC) with on ultraviolet spectrophotometric detector at 325 nm. Separation of the penicillin reaction products by HPLC was carried out by using a mobile phase of 0.1 M phosphate buffer and acetonitrile in ratios of 85:15 and 60:40 (vol/vol) in a gradient flow. The retention times of the seven penicillins ranged from 4.3 to 24.6 min, and the detection limits of penicillin concentration ranged from 0.04 to 0.2 μg/ml. The calibration curves for individual penicillins extracted from bovine serum were linear, and the correlation coefficients for each of the drugs were over 0.99. The determination of penicillins extracted from bovine serum spiked with each drug gave a recovery rate from 82.0 ± 5.6% to 105.6 ± 4.6%. This detection method may be useful for routine laboratory testing of residual penicillins.