Side effects of cephalosporins

Comparing piperacillin/tazobactam to current guidelines for the treatment of open fractures: A systematic review

Background

Current guidelines call for the use of a first-generation cephalosporin with or without an aminoglycoside for the treatment of open fractures. Due to its superior safety profile and single-dose administration, Piperacillin/tazobactam (PT) may be an effective alternative. The present systematic literature review aimed to evaluate the hypothesis that PT antibiotic prophylaxis does not differ in clinical outcomes as compared to the current guidelines in the treatment of open fractures.

Methods

Five databases were queried for literature pertaining to PT administration for open fractures. A 2-author screening process was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Methodologic index for non-randomized studies criteria was used to objectively assess the methodologic quality of the studies reviewed. Retrospective cohort studies that compared PT to current guidelines in open fractures were included.

Results

Four retrospective cohort studies consisting of 752 patients were included. The injury severity score (ISS) score was higher for the PT group, 18.1, versus the control group, 14.5 (p = .0008). Seventy-eight patients developed a surgical site infection (SSI) in the PT group versus 67 patients in the control group (p = .82). Twenty-one patients developed an acute kidney injury (AKI) in the PT group versus 19 in the control group (p = .51). There was no difference in the number of patients who developed resistant pathogens (6 (PT group) vs. 1 (control group); p = .99). Length of stay was greater in the PT group, 16.4 days, compared to the control group, 10.5 days (p=<0.00001).

Conclusion

The use of piperacillin/tazobactam for open fractures does not differ from first-generation cephalosporins with or without an aminoglycoside in regard to SSI, AKI, return to operating room, 1-year mortality, non-union, and development of resistant pathogens. LOS was significantly longer in the PT group but may be explained by a greater ISS. PT may be a non-inferior alternative to current guidelines due to its better safety profile and single-dose administration method, however, this review is limited by the lack of side effect reporting and underscores the need for larger prospective studies that compare side effect profiles between PT and control groups.

Kounis Syndrome: A Case Report and a Review of Recent Literature

Kounis syndrome (KS) is commonly defined as acute myocardial infarction (AMI) secondary to exposure to an allergen. There are multiple identified allergens that are associated with KS, examples include medications, food, and contrast media. After exposure to an allergen, the allergic pathway is triggered leading to vasospasm in coronary vessels which later on presents as AMI. A high index of clinical suspicion is of crucial importance as there are multiple variants of KS. Each type requires a different management approach depending on the severity of the presenting symptoms. Here, we present a case of a 65-year-old female with a history of transient ischemic attack (TIA) who presented to our hospital with symptoms of urinary tract infection and received the first dose of ceftriaxone while in the ER. She then developed symptoms of shortness of breath, chest pain, and diaphoresis associated with overall skin itchiness with ECG evidence of ST-elevation myocardial infarction (STEMI) in the inferior leads. She was given initial measures to treat possible allergic reactions including steroids and diphenhydramine and her ECG showed complete resolution after that; therefore, she was presumed to have KS after exposure to antibiotics. In this case report, we elaborate more about our case and further explore management options for KS.

Ensuring target concentrations of antibiotics in critically ill patients through dose adjustment

INTRODUCTION

Antibiotics are commonly prescribed in critical care, and given the large variability of pharmacokinetic (PK) parameters in these patients, drug PK frequently varies during therapy with the risk of either treatment failure or toxicity. Therefore, adequate antibiotic dosing in critically ill patients is very important.

AREAS COVERED

This review provides an overview of the basic principles of PK and pharmacodynamics of antibiotics and the main patient and pathogen characteristics that may affect the dosage of antibiotics and different approaches to adjust doses.

EXPERT OPINION

Dose adjustment should be done for aminoglycosides and glycopeptides based on daily drug concentration monitoring. For glycopeptides, in particular vancomycin, the residual concentration (Cres) should be assessed daily. For beta-lactam antibiotics, a loading dose should be administered, followed by three different possible approaches, as TDM is rarely available in most centers: 1) antibiotic regimens should be adapted according to renal function and other risk factors; 2) nomograms or software can be used to calculate daily dosing; 3) TDM should be performed 24-48 h after the initiation of treatment; however, the results are required within 24 hours to appropriately adjust dosage regimens. Drug dosing should be reduced or increased according to the TDM results.

Vitamin B12 may inhibit RNA-dependent-RNA polymerase activity of nsp12 from the SARS-CoV-2 virus

SARS‐CoV‐2 is the causative agent for the ongoing COVID19 pandemic, and this virus belongs to the Coronaviridae family. Like other members of this family, the virus possesses a positive‐sense single‐stranded RNA genome. The genome encodes for the nsp12 protein, which houses the RNA‐dependent‐RNA polymerase (RdRP) activity responsible for the replication of the viral genome. A homology model of nsp12 was prepared using the structure of the SARS nsp12 (6NUR) as a model. The model was used to carry out in silico screening to identify molecules among natural products, or Food and Drug Administration‐approved drugs that can potentially inhibit the activity of nsp12. This exercise showed that vitamin B12 (methylcobalamin) may bind to the active site of the nsp12 protein. A model of the nsp12 in complex with substrate RNA and incoming NTP showed that vitamin B12 binding site overlaps with that of the incoming nucleotide. A comparison of the calculated energies of binding for RNA plus NTP and methylcobalamin suggested that the vitamin may bind to the active site of nsp12 with significant affinity. It is, therefore, possible that methylcobalamin binding may prevent association with RNA and NTP and thus inhibit the RdRP activity of nsp12. Overall, our computational studies suggest that methylcobalamin form of vitamin B12 may serve as an effective inhibitor of the nsp12 protein.

Results of Intradermal Skin Testing with Cefazolin according to a History of Hypersensitivity to Antibiotics

BACKGROUND

The relationship between cephalosporin hypersensitivity and a history of β-lactam hypersensitivity is unclear. We evaluated the usefulness of routine intradermal cefazolin skin testing and its relationship with the history of β-lactam hypersensitivity.

METHODS

The electronic medical records of patients who underwent intradermal cefazolin (0.3 mg/mL) skin testing without negative controls from January 2010 to January 2011 at Seoul National University Bundang Hospital were evaluated. The history of β-lactam hypersensitivity of the patients was taken. Immediate adverse reactions after cefazolin injection were evaluated by searching the electronic medical records for key words and reviewing consultation documents of allergy specialists or dermatologists. The medical records of the patients were reviewed by an allergist.

RESULTS

There were 13,153 cases of cefazolin skin testing over the 13-month study period. Among the 12,969 cases with negative skin test results, 8 had immediate hypersensitivity related to cefazolin (0.06%). The negative predictive value of cefazolin skin testing alone was 99.94%. The overall positivity rate of cefazolin skin tests was 1.4% (184/13,153). Of the cases with a history of allergy to β-lactams, 15% (6/40) showed a positive cefazolin skin test result compared to only 1.36% (178/13,113) of cases with no such history (P < 0.001) including some false-positive tests.

CONCLUSION

The results suggest that routine screening involving cefazolin skin testing without negative controls is not useful for all patients, but could be helpful for those with a history of β-lactam hypersensitivity, although a large prospective study is needed to confirm this.

Risk Factors of Infection and Role of Antibiotic Prophylaxis in Totally Implantable Venous Access Port Placement: Propensity Score Matching

BACKGROUND

To evaluate risk factors of infection and effectiveness of preprocedural single-dose intravenous prophylactic antibiotic (PABX) during totally implantable venous access port (TIVAP) placement in preventing procedure-related infections.

METHODS

This was a retrospective single-institution multicenter study evaluating short-term (30-day) infection outcomes after TIVAP placement. Correlation between infection rates and clinical factors, including hematologic versus non-hematologic malignancy, inpatient versus outpatient status, single versus double lumen and PABX, was investigated using univariate and multivariable analysis in the overall study population as well as the propensity-score-matched cohort.

RESULTS

Overall, 5967 patients underwent TIVAP placement from 2005 to 2016, of which 3978 (67%) patients received PABX. On propensity score matching, 1952 patients with PABX were matched to the same number of patients without PABX. TIVAP was removed due to infection concern in 48 patients in unmatched and 30 patients in matched population. There was no difference in the rate of infection between those who received PABX and those who did not in both unmatched and matched population (p = 0.5387 and 0.9999). Although infection rate was significantly higher in patients who had TIVAP placement in inpatient setting (p < 0.0001), who received a double-lumen TIVAP (p < 0.0001), or who had hematologic malignancy (p = 0.0004) on univariate analysis, inpatient status was the sole factor associated with higher rate of TIVAP infection on multivariable analysis of both overall (odds ratio 2.31, p < 0.0001) and matched populations (odds ratio 4.36, p = 0.0004).

CONCLUSION

Placement of TIVAP in inpatient setting increases the risk of TIVAP infection. PABX before TIVAP placement does not prevent short-term procedure-related infections.

A prospective study of the incidence of drug-induced liver injury by the modern volatile anaesthetics sevoflurane and desflurane

BACKGROUND

Volatile anaesthetics are known to cause drug-induced liver injury, a hepatotoxic reaction characterised by antibodies to trifluoroacetylated lipid and protein adducts and cytochrome p450 2E1. The incidence of volatile anaesthetic drug-induced liver injury from older agents has been described, but modern agents have not been prospectively studied.

AIM

To determine prospectively the incidence of volatile anaesthetic drug-induced liver injury from sevoflurane and desflurane.

METHODS

Adult surgical patients with a predicted post-operative stay of at least 4 days were recruited. If volatile anaesthetic was administered, liver biochemistry was performed regularly. Medications, observations and other investigations were documented. Patients with abnormal liver biochemistry were classified as likely volatile anaesthetic drug-induced liver injury or not based on clinical assessment, Roussel Uclaf Causality Assessment Method score, and the absence of other likely pathology. Some patients were also tested for antibodies to both trifluoroacetylated lipid and protein adducts, and cytochrome p450 2E1.

RESULTS

A total of 209 patients were recruited, of which 121 were included for analysis. Post-operative liver biochemistry was abnormal in 62 patients (51.2%); further classified as not volatile anaesthetic drug-induced liver injury in 47 cases (38.8%), and likely volatile anaesthetic-drug induced liver injury in 15 cases (12.4%). Of the likely volatile anaesthetic drug-induced liver injury patients, only one had severe disease with alanine transaminase greater than five times the upper limit of normal, while four cases had moderate disease with alanine transaminase greater than three times the upper limit of normal. Thus, the incidence of clinically significant volatile anaesthetic drug-induced liver injury was 4.1%. No risk factors were identified.

CONCLUSIONS

Volatile anaesthetic drug-induced liver injury from modern agents seems to be as common (4.1%) as previously reported with older agents (3%), and may identify patients at risk of severe acute liver injury with subsequent re-exposure.

Synthesis and characterization of basil seed mucilage coated Fe3O4 magnetic nanoparticles as a drug carrier for the controlled delivery of cephalexin

A novel drug delivery system, loaded the drug cephalexin on the basil seed mucilage coated magnetic nanoparticles (Fe₃O₄@BSM-CPX) was prepared and characterized by means of X-ray diffraction (XRD), Furier Transform Infrared (FTIR), Field Emission Scanning Electron Microscope (FESEM), Vibrating Sample Magnetometer (VSM), Transmission Electron Microscopy (TEM), and Anti-bacterial, and Specific Surface (BET). By comparing the size of the uncoated nanoparticles (12nm) and the size of the coated magnetite nanoparticles (6nm), it was found that with the mucilage coating being put on the magnetite nanoparticles, the size of the nanoparticle cores has also decreased. The optimum pH results showed that the higher adsorption capacity occurs when cephalexin is cationic at pH2.5 because the NH₃⁺ group of cephalexin interacts better with negative functional groups of the basil seed mucilage. Disk Diffusion Anti-Bacterial test showed that the loading of CPX on the Fe₃O₄@BSM nanocarrier, not only does not have any negative effects on the structure and performance of the drug, but also increases the antibacterial properties of CPX. Furthermore, the in vitro release of Fe₃O₄@BSM-CPX nanocomposites showed an initial burst release in the first 18h, followed by a more gradual and sustained release for 120h.

Comparison of the effects of cefazolin and ceftriaxone on canine chondrocyte culture

Cephalosporins (CEFs) are antibiotics frequently used to treat bone infections and septic arthritis. The effects of CEFs on chondrocytes have not been studied until now. Cefazolin (cef1) and ceftriaxone (cef3), first-and third-generation CEFs, were selected to investigate their direct effects on normal and osteoarthritic (OA) primary canine chondrocytes, which were either nonstimulated or stimulated with the pro-inflammatory cytokine IL-1β. In our results, treatment with CEFs increased the negative effects on both conditioned normal and OA chondrocytes, especially when applied to IL-1β-stimulated cells (inflammatory stimulus). CEFs significantly decreased cell viability and induced apoptotic cell death in both normal and OA chondrocytes; moreover, treatment with cef1 caused necrotic cell death in OA chondrocytes. Cef3 treatment could increase s-GAG synthesis in normal cells preincubated with IL-1β, while cef1 had no significant effect. The expression of TNF was clearly downregulated after cef3 treatments, whereas it was upregulated after cef1 treatments. However, cef3 induced stronger downregulation of TIMP1 and the extracellular matrix component genes COL2A1 and ACAN. In conclusion, these results suggest both the cytotoxic effects of CEFs and their adverse effects on chondrogenic marker genes at the transcriptional level, which provide additional insight into the clinical application of cef1 and cef3.

Suspected Anaphylactic Reaction Prior to Induction of Anesthesia

Although uncommon, anaphylactic reactions during surgery are very dangerous and can result in serious morbidity. Various anesthetics can trigger anaphylactic reactions, and incidents with cephalosporin antibiotics are on the rise. In the case presented, an 84-year-old woman scheduled for calcaneus fracture surgery, was injected with cefbuperazone as a prophylactic antibiotic. On the way to the operating room, before induction of anesthesia, the patient lost consciousness and showed signs of hypoxemia, and anaphylactic reaction, which included hypotension, bronchospasm, and rash. Five hours after immediate intubation and fluid resuscitation, the patient was extubated and transferred to the general ward. Eight weeks later, the skin prick test confirmed a positive reaction to cefbuperazone.

Overtreatment of gonorrhea and chlamydial infections in 2 inner-city emergency departments

BACKGROUND

Infections with Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) are the most commonly reported sexually transmitted diseases in the United States.

OBJECTIVES

The primary objective of this study was to estimate the incidence of overtreatment of GC and CT infections in the emergency department (ED). The secondary objective was to determine if there are clinical variables that predict infection with GC and CT.

METHODS

A retrospective medical record review was performed at 2 inner-city hospitals. Records were obtained from the evaluation of female patients who presented to the ED between January 1, 2012, and December 31, 2012, who were tested for GC and CT infection. A standardized form was used to extract specific information from each medical record.

RESULTS

Data were extracted from 538 medical records. Of the 522 ED visits, 32 (6%) yielded test results positive for either GC or CT, including 3 that were positive for both. Treatment was administered to 101 patients (19%) and declined by an additional 9 (2%). Of those receiving antibiotics, 87 of 101 (0.86; 95% confidence interval, 0.77-0.92) had negative test results. Of those not offered antibiotics, 17 of 412 (0.04; 95% confidence interval, 0.02-0.07) had positive test results. The overtreatment proportion was similar at hospitals (55/66 [0.83] and 32/35 [0.91], respectively). Of clinical variables that were considered, only age less than 19 years was statistically associated with a positive test result for GC and CT.

CONCLUSION

The rate of overtreatment for GC and CT was 86%. The practice of empirical treatment should be reconsidered.

Antibiotics in frozen bone grafts can cause allergic reactions in recipient patients

Antibiotic prophylaxis is a routine procedure during total hip arthroplasty (THA), and the vast majority of cadavers within the multitissue procurement receive one or more antibiotics. Upon harvesting, bone grafts are stored in the bone banks on the temperature as low as -80°C for up to 5 years. It is shown in the literature that the antibiotics remain active and viable in the bone grafts even after being exposed to extremely low temperatures in the prolonged periods. Possibility of remnant antibiotic concentrations in the bone grafts and the fact that these antibiotic remnants maintain active even after being exposed to extremely low temperatures create the environment in which the possibility for the allergic reaction in sensitive patient receiving bone graft exists. We hypothesize that harvested bone grafts containing active antibiotic substance have the potential for local and systemic allergic reaction in sensitive recipient patients thus increasing morbidity and the costs of the treatment. Allergic reactions can mimic surgical site infections as well with the consequent substantial pitfalls in the treatment. Following that, in the setting of an assumed but not confirmed surgical site infection, the immunological evaluation on antibiotics for recipients of bone grafts could be added to the standard diagnostic algorithms. In addition, bone banks should be obliged to provide information of all potential drugs that can be found in every specific bone graft to the end users.

Immunologic evaluation of immediate hypersensitivity to cefaclor

PURPOSE

Cefaclor is widely prescribed for various infectious diseases. As its consumption increases, the number of hypersensitivity reactions to cefaclor has increased. This study aimed to evaluate the immunologic findings of immediate hypersensitivity to cefaclor.

MATERIALS AND METHODS

We enrolled 47 patients with immediate hypersensitivity to cefaclor from Ajou University Hospital and Asan Medical Center. Serum specific IgE, IgG1, and IgG4 antibodies to cefaclor-human serum albumin (HSA) conjugate were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The most common phenotype was anaphylaxis (Group I, 78.7%), followed by urticaria (Group II, 21.3%). The detection of specific IgE, IgG1, and IgG4 to cefaclor-HSA conjugate by ELISA tended to be higher in Group I (40.5%, 41.7%, 21.6%) than in Group II (20.0%, 20.0%, 0%) with no statistical significance. Significant associations were found between specific IgE and IgG1 or IgG4 (p<0.001, p=0.019). ELISA inhibition tests showed significant inhibitions by both free cefaclor and cefaclor-HSA conjugate. For basophil activation tests in patients having no specific IgE antibody, the CD63 expression level on basophils increased with incubations of free cefaclor.

CONCLUSION

The most common manifestation of immediate hypersensitivity to cefaclor was anaphylaxis, most of which was mediated by IgE; however, a non-IgE mediated direct basophil activation mechanism was suggested in a subset of anaphylaxis patients.

Diagnosis and management of immediate hypersensitivity reactions to cephalosporins

Cephalosporins can cause a range of hypersensitivity reactions, including IgE-mediated, immediate reactions. Cephalosporin allergy has been reported with use of a specific cephalosporin, as a cross-reaction between different cephalosporins or as a cross-reaction to other β-lactam antibiotics. Unlike penicillins, the exact allergenic determinants of cephalosporins are less well understood and thus, standardized diagnostic skin testing is not available. Nevertheless, skin testing with diluted solutions of cephalosporins can be valuable in confirming IgE-mediated hypersensitivity reactions. In vitro tests are in development using recent technological advances and can be used as complementary tests. However, they are not commonly used because of their reduced sensitivity and limited availability. In selected cases of inconclusive results in both skin tests and IgE assays, a graded challenge or induction of drug tolerance with the implicated cephalosporin should be performed.

Beta-Lactam Hypersensitivity and Cross-Reactivity

Penicillin is the most frequently reported cause of drug allergy, and cross-reactivity of penicillins with other beta-lactam antibiotics is an area of debate. This review evaluates the available data on immunoglobulin E-mediated penicillin hypersensitivity and cross-reactivity with cephalosporin, carbapenem, and monobactam antibiotics. A MEDLINE search was conducted from 1950 to October 2013, and selected references from review articles were also evaluated. There is a wide variety in reported incidences of cross-reactivity between penicillins and cephalosporins or carbapenems, with early retrospective studies suggesting up to 41.7% and 47.4% cross-reactivity, respectively. Conversely, the use of monobactam antibiotics is frequently employed in the case of a penicillin allergy, as prescribers believe that there is no cross-reactivity between the 2 drug classes. More recent prospective studies suggest that the rates of cross-reactivity with cephalosporins and carbapenems are <5% and <1%, respectively. Similarities in penicillin and cephalosporin side chains may play a role in cross-reactivity between these classes. Cross-reactivity with monobactams is essentially negligible; however, there are some clinical data to support an interaction between ceftazidime and aztreonam, due to the similarity of their side chains. The data reviewed suggest that avoidance of other beta-lactams in patients with type 1 hypersensitivity to penicillins should be reconsidered.

Kounis syndrome: acute inferior myocardial infarction with atroventricular node block due to ceftriaxone: a first reported case

Cefriaxone is a third-generation cephalosporin that might rarely cause a severe allergic reaction. Acute cardiac emergencies are quite rare in the setting of drug allergies. Here, we report the first case of myocardial infarction and AV-block after intravenous cefriaxone administration.

Fatal case of cephalexin-induced toxic epidermal necrolysis

Purpose:

To describe a case of toxic epidermal necrolysis likely caused by cephalexin with a review of the literature.

Case:

An 80-year-old male with a known allergy to cephalosporins, residing at a long-term acute care hospital, received cephalexin for a urinary tract infection. And 1 day after starting therapy, the patient developed an extensive erythematous rash accompanied by skin sloughing; 4 days after receiving cephalexin, the patient was directly admitted to the burn intensive care unit and was diagnosed with toxic epidermal necrolysis involving 56% of the total body surface area. Progressive deterioration to multisystem organ failure ensued, and the patient died 5 days following his admission to the burn intensive care unit. At the time of death, ulcerations were noted over approximately 80% of his body.

Summary:

The temporal association of the patient’s ingestion of cephalexin for a urinary tract infection to his onset of toxic epidermal necrolysis suggests that this 80-year-old man developed toxic epidermal necrolysis following the administration of cephalexin for a urinary tract infection.

T cell responses to drugs and drug metabolites

Understanding the chemical mechanisms by which drugs and drug metabolites interact with cells of the immune system is pivotal to our knowledge of drug hypersensitivity as a whole.In this chapter, we will discuss the currently accepted mechanisms where there is scientific and clinical evidence to support the ways in which drugs and their metabolites interact with T cells. We will also discuss bioanalytical platforms, such as mass spectrometry, and in vitro test assays such as the lymphocyte transformation test that can be used to study drug hypersensitivity; the combination of such techniques can be used to relate the chemistry of drug antigen formation to immune function. Ab initio T cell priming assays are also discussed with respect to predicting the potential of a drug to cause hypersensitivity reactions in humans in relation to the chemistry of the drug and its ability to form haptens, antigens and immunogens in patients.

Validation of the cephalosporin intradermal skin test for predicting immediate hypersensitivity: a prospective study with drug challenge

BACKGROUND

Cephalosporin is a major offending agent in terms of drug hypersensitivity along with penicillin. Cephalosporin intradermal skin tests (IDTs) have been widely used; however, their validity for predicting immediate hypersensitivity has not been studied. This study aimed to determine the predictive value of cephalosporin intradermal skin testing before administration of the drug.

METHODS

We prospectively conducted IDTs with four cephalosporins, one each of selected first-, second-, third-, or fourth-generation cephalosporins: ceftezol; cefotetan or cefamandole; ceftriaxone or cefotaxime; and flomoxef, respectively, as well as with penicillin G. After the skin test, whatever the result, one of the tested cephalosporins was administered intravenously and the patient was carefully observed.

RESULTS

We recruited 1421 patients who required preoperative cephalosporins. Seventy-four patients (74/1421, 5.2%) were positive to at least one cephalosporin. However, none of responders had immediate hypersensitivity reactions after a challenge dose of the same or different cephalosporin, which were positive in the skin test. Four patients who suffered generalized urticaria and itching after challenge gave negative skin tests for the corresponding drug. The IDT for cephalosporin had a sensitivity of 0%, a specificity of 97.5%, a negative predictive value of 99.7%, and a positive predictive value (PPV) of 0%, when challenged with the same drugs that were positive in the skin test.

CONCLUSION

Routine skin testing with a cephalosporin before its administration is not useful for predicting immediate hypersensitivity because of the extremely low sensitivity and PPV of the skin test (CRIS registration no. KCT0000455).

Intestinal tract injury by drugs: Importance of metabolite delivery by yellow bile road

Drug secretion into bile is typically considered a safe route of clearance. However, biliary delivery of some drugs or their reactive metabolites to the intestinal tract evokes adverse consequences due to direct toxic actions or indirect disruption of intestinal homeostasis. Biliary concentration of the chemotherapy agent 5-fluorodeoxyuridine (FUDR) and other compounds is associated with bile duct damage while enterohepatic cycling of antibiotics contributes to the disruptions of gut flora that produce diarrhea. The goal of this review is to describe key evidence that biliary delivery is an important factor in the intestinal injury caused by representative drugs. Emphasis will be given to 3 widely used drugs whose reactive metabolites are plausible causes of small intestinal injury, namely the nonsteroidal anti-inflammatory drug (NSAID) diclofenac, the immunosuppressant mycophenolic acid (MPA), and the chemotherapy agent irinotecan. Capsule endoscopy and other sensitive diagnostic techniques have documented a previously unappreciated, high prevalence of small intestinal injury among NSAID users. Clinical use of MPA and irinotecan is frequently associated such severe intestinal injury that dosage must be reduced. Observations from clinical and experimental studies have defined key events in the pathogenesis of these drugs, including roles for multidrug resistance-associated protein 2 (MRP2) and other transporters in biliary secretion and adduction of enterocyte proteins by reactive acyl glucuronide metabolites as a likely mechanism for intestinal injury. New strategies for minimizing the adverse intestinal consequences of irinotecan chemotherapy illustrate how basic information about key events in the biliary secretion of drugs and the nature of their proximate toxicants can lead to safer protocols for drugs.

Diagnosing immediate reactions to cephalosporins

BACKGROUND

After penicillins, cephalosporins are the betalactams that most often induce IgE-mediated reactions. The development of diagnostic tests has been delayed, however, because the cephalosporin allergenic determinants have not been properly identified.

OBJECTIVE

To evaluate the usefulness of skin tests, serum specific IgE assays, and challenges in diagnosing immediate reactions to cephalosporins and to clarify the pathogenic mechanism of such reactions.

METHODS

We studied 76 adults with immediate reactions to cephalosporins, mainly ceftriaxone, cefotaxime, and ceftazidime. Skin tests and serum specific IgE assays were performed for culprit cephalosporins and cefaclor, as well as for penicillin, amoxicillin, and ampicillin. Some subjects with negative results underwent challenges and re-evaluations. Responses to cephalosporins other than the culprit ones were also studied.

RESULTS

In the first allergologic work-up, an IgE-mediated hypersensitivity to penicillins and/or cephalosporins was diagnosed in 63 (82.9%) of the 76 patients on the basis of skin-test and/or specific IgE assay positivity. Of the 13 negative patients, eight accepted challenges and underwent re-evaluations. Considering both first- and second-evaluation results, the skin-test-positivity rate increased from 76.3% to 85.5% and that of sepharose-radioimmunoassay positivity from 67.1% to 74.3%. Overall, an IgE-mediated hypersensitivity was diagnosed in 70 patients (in seven after retesting). On the basis of skin-test and CAP-FEIA results, we classified our 76 patients into five groups: group A (three patients), positive only to penicillin reagents; B (17), positive to both cephalosporin and penicillin reagents; C (24), positive to more than one cephalosporin; D (21), positive only to the responsible cephalosporin; E (11) negative to skin tests and CAP-FEIA, including five sepharose-radioimmunoassay positive.

CONCLUSIONS

Most immediate reactions to cephalosporins appear to be IgE-mediated. Cephalosporin skin testing and sepharose-radioimmunoassay are useful tools for evaluating these reactions. Cephalosporin IgE-mediated hypersensitivity may be a transient condition; therefore, allergologic exams should be repeated in patients with negative initial allergologic work-ups, including challenges.

A review of evidence supporting the American Academy of Pediatrics recommendation for prescribing cephalosporin antibiotics for penicillin-allergic patients

The American Academy of Pediatrics, evidence-based guidelines endorse the use of cephalosporin antibiotics for patients with reported allergies to penicillin, for the treatment of acute bacterial sinusitis and acute otitis media. Many physicians, however, remain reluctant to prescribe such agents. Although such concern is understandable, lack of consistent data regarding exactly what constitutes an initial penicillin-allergic reaction and subsequent cross-sensitivity to cephalosporins may be preventing many patients from receiving optimal antibiotic therapy. This article reviews evidence in support of the American Academy of Pediatrics recommendation. Included is an examination of the types and incidence of reactions to penicillins and cephalosporins; the frequency of cross-reactivity between these 2 groups of agents; experimental and clinical studies that suggest that side chain-specific antibodies predominate in the immune response to cephalosporins, thereby explaining the lack of cross-sensitivity between most cephalosporins and penicillins; the role of skin testing; and the risks of anaphylaxis. Specific recommendations for the treatment of patients on the basis of their responses to previously prescribed agents are summarized.

Cephalosporin allergy

Allergic reactions to cephalosporins may occur because of sensitization to cephalosporin determinants shared with penicillin or to unique cephalosporin haptens. The exact nature of the haptenic determinants resulting from the degradation of currently available cephalosporins is incompletely understood. Cephalosporin skin testing or specific IgE immunoassays have limited clinical utility. Patients with a history of allergy to cephalosporins or penicillin may be at increased risk for a reaction to cephalosporins. Skin testing for an allergy to penicillin may be helpful in patients with a history of penicillin allergy who have a clinical indication for cephalosporin use. Most of these patients have negative tests and should not be at increased risk for a reaction to cephalosporins.

[Problems of pharmacotherapy of infections in the aged]

Infectious diseases play an important role in the elderly. Disease progression is often more severe, displaying a higher complication rate and causing increased mortality. Elderly patients suffer more frequently than younger under pneumonia, exacerbations of chronic bronchitis, urinary tract infections as well as skin and soft tissue infections. When starting empiric antibiotic therapy one should consider that the bacterial spectrum afflicting elderly patients may differ from that afflicting younger patients. In addition an increasing number of nosocomial and multiresistant pathogens is seen in elderly patients due to more frequent hospitalisation and living in nursing homes. Patient multimorbidity and multiple co-medications make awareness of important drug-interactions essential. The purpose of this article is to review the indications and side-effects of well-tried and newer antibiotics with respect to patients age. Especially the newer antibiotics Ertapenem, Linezolid, Quinupristin/Dalfopristin and Telithromycin are discussed in detail.

Efficacy of cephalexin two vs. three times daily vs. cefadroxil once daily for streptococcal tonsillopharyngitis

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral cephalexin twice vs. three times daily vs. cefadroxil once daily as therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. A prospective open-label, observational cohort study was conducted over 18 months (January 2000-June 2001). Children enrolled had an acute onset of symptoms and signs of a tonsillopharyngeal illness and a laboratory-documented GABHS infection. Follow-up examination and laboratory testing occurred 21 +/- 4 days following enrollment. Two hundred seventy-one patients were enrolled (intent to treat group): 63 received cephalexin twice daily, 124 received cephalexin three times daily, and 84 received cefadroxil once daily. Fifty-three children did not return for the follow-up visit, leaving 218 patients in the per-protocol group: 54 cephalexin twice-daily treated, 94 cephalexin 3-times daily treated, and 70 cefadroxil once-daily treated. In the per-protocol group, bacteriologic cure for those treated with cephalexin twice daily was 87%, for cephalexin 3 times daily, it was 81% and for cefadroxil once daily it was 81% (p = 0.61). The clinical cure rate for cephalexin twice-daily treatment was 91%; for three-times daily, it was 86%; and for cefadroxil once daily, it was 84% (p = 0.56). Because treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. Younger age of patient was significantly associated with bacteriologic (p = 0.04) and clinical (p = 0.01) failure independent of treatment group but in the adjusted logistic model no differences were found among the 3 treatment regimens. Cephalexin dosed twice daily or three times daily and cefadroxil dosed once daily appear equivalent in bacteriologic and clinical cure of GABHS tonsillopharyngitis.

The Treatment of Severe Group A Streptococcal Infections

Group A streptococci can cause a variety of diseases ranging from uncomplicated superficial infections to severe systemic infections associated with high morbidity and mortality. Since the late 1980s a drastic resurgence of highly aggressive invasive streptococcal infections, including streptococcal toxic shock syndrome and necrotizing fasciitis, have been noted worldwide. This has prompted intense research in the field and important new information has been gained regarding the pathogenesis and treatment of life-threatening invasive group A streptococcal infections. Exotoxins with superantigenic activities have been identified as central mediators of the systemic effects seen in streptococcal toxic shock syndrome. Novel therapeutic strategies include agents that can inhibit these superantigens, and one promising candidate is intravenous polyspecific immunoglobulin that contains neutralizing antibodies against a wide spectrum of streptococcal superantigens. Intravenous immunoglobulin adjunctive therapy was shown in a case-control study to reduce mortality in patients with streptococcal toxic shock syndrome.

[Severe pneumococcal meningitis and ceftriaxone allergy]

We report the case of a 51-year-old man with an allergy to amoxicillin/acid clavulanique who presented with Streptococcus pneumoniae meningitis. Initial treatment consisted of an association of antibiotics including ceftriaxone. Six days after treatment was initiated the patient developed skin reaction and the diagnosis of allergy to ceftriaxone was established by the dosage of specific IgE. Typically Streptococcus pneumoniae meningitis is treated with vancomycin and a third-generation cephalosporin. This association had to be modified because cross allergy to cephalosporins could have developed in this patient who had previously reacted to penicillins.

Open-Label, parallel-group, multicenter, randomized study of cefprozil versus erythromycin in children with group A streptococcal pharyngitis/tonsillitis

BACKGROUND

Cefprozil and erythromycin are acceptable alternatives to penicillin in the treatment of pharyngitis/tonsillitis due to group A beta-hemolytic streptococcus (GABHS).

OBJECTIVE

The purpose of this trial was to determine the relative efficacy and tolerability of cefprozil and erythromycin in the treatment of pediatric pharyngitis/tonsillitis due to GABHS.

METHODS

This trial compared the bacteriologic and clinical efficacy of erythromycin and cefprozil in children 2 to 12 years of age with culture-documented GABHS pharyngitis/ tonsillitis. Children who were allergic to penicillin, cefprozil, or erythromycin were excluded. Patients were prospectively randomly assigned to receive 10 days of oral therapy with either cefprozil suspension 15 mg/kg per day in 2 divided doses or erythromycin ethylsuccinate suspension 30 mg/kg per day in 3 divided doses. Primary efficacy end points were bacteriologic and clinical response 2 to 8 days after treatment ended. The frequency and severity of adverse events and their relationship to treatment were also assessed.

RESULTS

A total of 199 patients were enrolled and treated (cefprozil, 99; erythromycin, 100); 12 patients in the cefprozil group and 15 in the erythromycin group were not evaluable. The GABHS eradication rate was significantly higher with cefprozil (95%) than with erythromycin (74%) (P = 0.001). The posttreatment carrier rate was lower in the cefprozil group (5%) than in the erythromycin group (18%) (95% CI, -22.3 to -3.8). Clinical cure rate was 90% (78/87) with cefprozil and 91% (77/85) with erythromycin (P = 0.95) (treatment group difference, -0.93; 95% CI, -9.9% to 8.0%). The overall incidence of drug-related adverse events was not significantly different in the 2 groups (11% with cef- prozil, 18% with erythromycin). The most common adverse events were diarrhea and vomiting. Two patients in the erythromycin group discontinued therapy because of adverse events.

CONCLUSIONS

The bacteriologic eradication rate was significantly greater with cefprozil compared with erythromycin in children with pharyngitis/tonsillitis. Both cefprozil and erythromycin produced a clinical cure in >90% of patients.

Delayed hypersensitivity to cefazolin: report on a case involving lymphocyte transformation studies with different cephalosporins

BACKGROUND

A cell-mediated immunopathogenic mechanism has been demonstrated in only a few cases of cutaneous reactions to systemically administered cephalosporins.

OBJECTIVE

The aim was to investigate the pathogenic mechanism of a maculopapular rash experienced by a subject during cefazolin therapy.

METHODS AND RESULTS

Prick, intradermal, and patch tests were carried out using penicillin determinants, ampicillin, amoxicillin, cefazolin, cephalothin, cefuroxime, ceftazidime, and ceftriaxone. Those tests for penicillin G and its determinants, as well as for ampicillin and amoxicillin, were negative. The patient displayed patch-test and delayed intradermal-test positivity to all the cephalosporins tested. No specific immunoglobulin E antibodies were found for penicillins or cefazolin. The lymphocyte-transformation-test results were negative for all the penicillins tested and showed a positive concentration-effect curve for cefazolin, ceftazidime, and ceftriaxone at concentrations up to 50 microg/mL. At 100 microg/mL the responses decreased with all the cephalosporins tested. Challenges with penicillin G and amoxicillin were well tolerated, but the challenge with cefazolin was positive.

CONCLUSIONS

The data of this case demonstrate delayed hypersensitivity to cefazolin. Patch tests and delayed-reading intradermal tests can be a simple and effective means of diagnosing this type of reaction. Both in vivo and in vitro studies indicate that the responses were directed toward a determinant shared by all cephalosporins, but not by penicillins. The concentration of the cephalosporins used for the in vitro lymphocyte stimulation was critical, because at the concentrations normally used to test other beta-lactams the response decreased. This phenomenon may be attributable to an immunosuppressive, rather than toxic, effect.

Spectrum of clinical and histopathologic responses to intracranial electrodes: from multifocal aseptic meningitis to multifocal hypersensitivity-type meningovasculitis

PURPOSE

We sought to characterize and compare the histopathologic and clinical changes elicited by subdural and depth electrodes in subjects undergoing epilepsy surgery evaluation.

METHODS

A retrospective review of clinical records, imaging and histopathologic studies of epilepsy surgery cases requiring subdural strips and depth electrodes for localization of epileptogenic tissue was performed between 1993 and 1999. Forty-nine subjects had a combination of subdural and depth, whereas 10 had depth electrodes only. Histopathologic changes were classified as mild, moderate, or severe based on the density, extent, and composition of the inflammatory infiltrate.

RESULTS

Subdural electrodes induced a clinical picture of transient aseptic meningitis; histopathologically, the infiltrates were moderate in degree in the majority (73%) and severe in the remainder (27%), with T cells and eosinophils infiltrating the cortex and arteriolar walls (hypersensitivity-type response). Depth electrodes alone caused minimal or no symptoms of meningeal irritation; the cellular response elicited by these electrodes was mild in five and moderate in the remaining five cases; severe inflammation was not observed in this group. Although the proportion of small clinically silent hematomas was larger in cases with depth (five of 59) compared with subdural electrodes (one of 49), microhemorrhages were considerably more numerous with subdural than with depth electrodes.

CONCLUSIONS

These results suggest that the spectrum of brain responses to foreign bodies is wide, ranging from self-limited physiologic to hypersensitivity-type reactions of varying severity. Subdural strips elicited more intense inflammation than did depth electrodes. The histopathologic extent of the reaction to either type of electrodes could not be precisely defined because of the retrospective nature of this study. History of allergy to latex or previous craniotomies are probable risk factors for the hypersensitivity-type reaction. Surgical outcome, excellent in the majority, was independent of the severity or type of inflammation, and there have not been neurologic or systemic sequelae.

Systemic antibiotic agents

Understanding the breadth of systemic antimicrobial agents available for use by the dermatologist and their associated side-effect profiles and drug interactions allows the clinician to offer patients optimal care in the management of cutaneous infectious disease.

The cephalosporins

The cephalosporins are a large group of related beta-lactam antimicrobial agents. Favorable attributes of the cephalosporins include low rates of toxicity, relatively broad spectrum of activity, and ease of administration. Various cephalosporins are effective for treatment of many conditions, including pneumonia, skin and soft tissue infections, bacteremia, and meningitis. Differences among the numerous cephalosporin antimicrobial agents are sometimes subtle; however, an understanding of these differences is essential for optimal use of these agents. As a result of widespread use of cephalosporins, bacterial resistance to these drugs is increasingly common. New, fourth-generation agents (such as cefepime) offer an alternative for the treatment of infections caused by some drug-resistant microorganisms.

Diagnosis of penicillin, amoxicillin, and cephalosporin allergy: reliability of examination assessed by skin testing and oral challenge

The specificity of pediatrician-diagnosed allergy reactions to penicillin, amoxicillin, and oral cephalosporins, which was based on contemporaneous examination of the patient, was evaluated by an elective skin testing program. Children and adolescents (n = 247) experiencing an adverse reaction to penicillin, amoxicillin, and/or an oral cephalosporin sufficient to lead to the recommendation to avoid further use were enrolled. Skin testing with penicillin G, commercial benzylpenicilloyl phosphate, penicillin minor determinate mixture, ampicillin, cefazolin, cefuroxime, and ceftriaxone was performed according to the suspected drug allergy followed by an oral challenge, repeat testing, and prospective follow-up if no reactions were observed. Overall, 84 (34.0%) of 247 patients had an IgE-type reaction on skin testing or oral challenge. Twenty-seven (32%) of 85 suspected penicillin reactions, 53 (34%) of 156 suspected amoxicillin reactions, and 13 (50%) of 26 suspected cephalosporin reactions were shown to be IgE mediated. Positive skin tests were observed in 20 patients with non-IgE-type clinical adverse reactions, including 15 patients with only a pruritic polymorphous rash. No reactions to oral challenge were severe after negative skin testing. One hundred sixty-three patients received multiple treatment courses with beta-lactam antibiotics after a negative skin testing procedure and three (1.8%) had adverse IgE reactions, all of which were mild. Physician-diagnosed allergic reactions to beta-lactam antibiotics based on patient examination at the time of the reaction is more accurate than patient history alone but still overestimates the rate of possible true allergy in 66% of patients. Elective penicillin, amoxicillin, and cephalosporin skin testing and oral challenge protocols are necessary to identify patients not at risk.