Contemporary use of cefazolin for MSSA infective endocarditis: analysis of a national prospective cohort.

OBJECTIVES: This study aimed to assess the real use of cefazolin for methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) in the Spanish National Endocarditis Database (GAMES) and to compare it with antistaphylococcal penicillin (ASP). METHODS: Prospective cohort study with retrospective analysis of a cohort of MSSA IE treated with cloxacillin and/or cefazolin. Outcomes assessed were relapse; intra-hospital, overall, and endocarditis-related mortality; and adverse events. Risk of renal toxicity with each treatment was evaluated separately. RESULTS: We included 631 IE episodes caused by MSSA treated with cloxacillin and/or cefazolin. Antibiotic treatment was cloxacillin, cefazolin, or both in 537 (85%), 57 (9%), and 37 (6%) episodes, respectively. Patients treated with cefazolin had significantly higher rates of comorbidities (median Charlson Index 7, P <0.01) and previous renal failure (57.9%, P <0.01). Patients treated with cloxacillin presented higher rates of septic shock (25%, P = 0.033) and new-onset or worsening renal failure (47.3%, P = 0.024) with significantly higher rates of in-hospital mortality (38.5%, P = 0.017). One-year IE-related mortality and rate of relapses were similar between treatment groups. None of the treatments were identified as risk or protective factors. CONCLUSION: Our results suggest that cefazolin is a valuable option for the treatment of MSSA IE, without differences in 1-year mortality or relapses compared with cloxacillin, and might be considered equally effective.

Cloxacillin plus fosfomycin versus cloxacillin alone for methicillin-susceptible Staphylococcus aureus bacteremia: a randomized trial.

Treatment failure occurs in about 25% of patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. We assessed whether cloxacillin plus fosfomycin achieves better treatment success than cloxacillin alone in hospitalized adults with MSSA bacteremia. We conducted a multicenter, open-label, phase III-IV superiority randomized clinical trial. We randomly assigned patients (1:1) to receive 2 g of intravenous cloxacillin alone every 4 h or with 3 g of intravenous fosfomycin every 6 h for the initial 7 days. The primary endpoint was treatment success at day 7, a composite endpoint with the following criteria: patient alive, stable or with improved quick Sequential Organ Failure Assessment score, afebrile and with negative blood cultures for MSSA, adjudicated by an independent committee blinded to treatment allocation. We randomized 215 patients, of whom 105 received cloxacillin plus fosfomycin and 110 received cloxacillin alone. We analyzed the primary endpoint with the intention-to-treat approach in 214 patients who received at least 1 day of treatment. Treatment success at day 7 after randomization was achieved in 83 (79.8%) of 104 patients receiving combination treatment versus 82 (74.5%) of 110 patients receiving monotherapy (risk difference 5.3%; 95% confidence interval (CI), -5.95-16.48). Secondary endpoints, including mortality and adverse events, were similar in the two groups except for persistent bacteremia at day 3, which was less common in the combination arm. In a prespecified interim analysis, the independent committee recommended stopping recruitment for futility prior to meeting the planned randomization of 366 patients. Cloxacillin plus fosfomycin did not achieve better treatment success at day 7 of therapy than cloxacillin alone in MSSA bacteremia. Further trials should consider the intrinsic heterogeneity of the infection by using a more personalized approach. ClinicalTrials.gov registration: NCT03959345 .

Cloxacillin-induced acute vanishing bile duct syndrome: A case study and literature review.

Ductopenia is often regarded as a chronic process where ≥50% of portal tracts lack bile ducts, which is also known as vanishing bile duct syndrome (VBDS). One aetiology is drug-induced liver injury. Cloxacillin, an antistaphylococcal penicillin, typically causes "bland" cholestasis. We present the first case of cloxacillin-induced acute ductopenia or VBDS and a review of published cloxacillin-induced liver injuries. A 66-year-old woman with no prior liver disease, but known penicillin allergy, was treated for postcarotid angioplasty staphylococcal infection with 6 weeks of cloxacillin. She presented with a 2-week history of weakness and jaundice. Laboratory work-up showed elevated liver enzymes with a cholestatic pattern, hyperbilirubinemia and eosinophilia. She required ICU transfer for hypotension and was started empirically on prednisone. Liver biopsy revealed severe centrilobular cholestasis, mild necroinflammation and ductopenia with epithelial injury, but no ductular reaction. Two months later she was discharged on hydrocortisone and ursodiol with persistently elevated alkaline phosphatase and bilirubin. She was considered for liver transplantation but died of liver failure 4 months later. Four additional articles were found with histopathologic descriptions of cloxacillin-related liver injury. These included portal inflammation, cholestasis and mild necroinflammation. Clinical features were reported in two cases; both had mild symptoms with cholestatic liver enzymes and hyperbilirubinemia. Both patients recovered completely within 10-60 days. Cloxacillin-induced cholestasis can be secondary to acute ductopenia, which can result in worse clinical outcomes than previously described "bland" cholestasis. Liver biopsy is recommended to identify cases with acute VBDS.

Cefazolin versus cloxacillin as definitive antibiotic therapy for methicillin-susceptible Staphylococcus aureus spinal epidural abscess: a retrospective cohort study.

OBJECTIVES: We compared the effectiveness of cefazolin and cloxacillin as definitive antibiotic therapy for methicillin-susceptible Staphylococcus aureus (MSSA) spinal epidural abscess (SEA). METHODS: This retrospective cohort study included patients with MSSA SEA from two academic hospitals in Hamilton, Ontario, Canada, between 2014 and 2020. Patients treated with cefazolin were compared to those treated with cloxacillin. Co-primary outcomes included 90-day mortality, antibiotic failure, adverse reactions and recurrence. Inverse probability of treatment weighting using propensity scores was used to balance important prognostic factors and to estimate an adjusted risk difference. RESULTS: Of 98 patients with MSSA SEA, 50 and 48 patients were treated with cefazolin and cloxacillin, respectively. Mortality at 90 days was 8% and 13% in the cefazolin and cloxacillin groups, respectively (P = 0.52). The antibiotic failure rate was 12% and 19% in the cefazolin and cloxacillin groups, respectively (P = 0.41). The serious adverse reactions rate was 0% and 4% in the cefazolin and cloxacillin groups, respectively (P = 0.24). The recurrence rate was 2% and 8% in the cefazolin and cloxacillin groups, respectively (P = 0.20). The adjusted risk difference for mortality at 90 days was -1% [95% confidence interval (CI) -10% to 8%] favouring cefazolin. The adjusted risk differences for antibiotic failure, adverse reactions and recurrence were 1% (95% CI -12% to 14%), -5% (95% CI -11% to 2%) and -18% (-36% to -1%) respectively. CONCLUSION: Cefazolin is likely as effective as an antistaphylococcal penicillin and may be considered as a first-line treatment for MSSA SEA.

Fixed-dose combination antibiotics: The search for evidence using the example of ampicillin-cloxacillin.

High consumption of irrational fixed-dose combination (FDC) antibiotics may pose a threat of antimicrobial resistance. In India, ampicillin-cloxacillin was the second highest sold FDC antibiotic behind amoxicillin and clavulanic acid. There remain, however, questions about its efficacy and safety and a lack of regulatory approval. We undertook a literature review for ampicillin-cloxacillin to identify available data on the safety and efficacy of its used as FDC. We identified 1071 studies for screening and 81 studies were considered for inclusion. Only 12 studies in English language were accessible full texts for final review. None of the studies identified provided strong evidence that ampicillin-cloxacillin differed in safety or efficacy to other treatments used, and in particular to the component antibiotics used alone. To fully assess the efficacy and safety of ampicillin-cloxacillin and other FDCs, a standardised search format would be required. This should include broad international collaboration, including contacting the relevant regulatory authorities to facilitate a more evidence-based approach to their use.

Intravenously administered cloxacillin-induced neutropenia with eosinophilia in a patient with infective endocarditis: a case report.

BACKGROUND: Bacteremia following Staphylococcus aureus is a serious clinical condition which is often associated with distant metastatic infections. One of the most dreaded complications of Staphylococcus aureus bacteremia is infective endocarditis. Cloxacillin is a common antibiotic prescribed for suspected staphylococcal infections and confirmed methicillin-sensitive Staphylococcus aureus infections. Prolonged use of cloxacillin may lead to neutropenia. CASE PRESENTATION: A 38-year-old Sinhalese man presented to Teaching Hospital Kurunegala, Sri Lanka, complaining of a 3-week history of fever; he was found to have a pansystolic murmur over the apex of his heart. He had leukocytosis with predominant neutrocytosis. His C-reactive protein was 231 mg/l and erythrocyte sedimentation rate was 100 mm/first hour. Transthoracic two-dimensional echocardiography revealed prolapsed mitral valve with 7 × 13 mm vegetation over the posterior mitral valve. On the following day, three blood cultures became positive and were subsequently identified as Staphylococcus aureus. Intravenously administered cloxacillin 3 g 6 hourly was started. Following day 24 of intravenously administered cloxacillin, our patient developed high spike fever. His total white blood cells were: 990/mm3 with 34% neutrophils and 22% eosinophils. His hemoglobin concentration was 9.5 g/dL and platelet count remained normal (202 × 106/mm3). His C-reactive protein was 78 mg/l, erythrocyte sedimentation rate was 95 mm/first hour, and he was otherwise comfortable, showing no signs of sepsis beside the high grade fever. His serum was negative for filarial and Toxoplasma antibodies while stool was negative for oocytes and amoebic cysts. Further, his serum was negative for dengue virus, Epstein-Barr virus, cytomegalovirus, and hepatitis B antibodies. He was clinically well on day 6 after stopping cloxacillin with 44% neutrophils and 18% eosinophils. His C-reactive protein and erythrocyte sedimentation rate became normal, and there was no further plan for cardiothoracic intervention or administration of antimicrobials. He was discharged from hospital and remained well 6 months later. CONCLUSION: This case report signifies the potential fatal adverse effect of cloxacillin in methicillin-sensitive Staphylococcus aureus infections. Leukopenia is associated with prolonged use of high doses of cloxacillin. In addition to transthoracic two-dimensional echocardiography and inflammatory markers, sequential white blood cells and differential counts would help clinicians to assess the prognosis of patients with infective endocarditis.

Successful desensitization to cloxacillin in a patient with sepsis, with infective endocarditis and clinical suspicion of hypersensitivity to penicillins, a case report.

WHAT IS KNOWN AND OBJECTIVE: Beta-lactam antibiotic (BLA) therapy is frequently needed to treat infective endocarditis (IE). Hypersensitive reactions to BLA restrict BLA therapy in allergic patients. In the current case, we aim to describe the utility of desensitization (DS) in this context. Although the evidence is limited, DS is recommended. CASE DESCRIPTION: This case report deals with a 79-year-old woman with a clinical suspicion of allergy to BLA and a methicillin-sensitive Staphylococcus aureus (MSSA) IE. A cloxacillin DS protocol was developed to enable treatment with cloxacillin. WHAT IS NEW AND CONCLUSION: Alternative antibiotic treatments may be less effective or not available in MSSA IE. In this case report, DS allowed optimal cloxacillin treatment.

Daptomycin versus placebo as an adjunct to beta-lactam therapy in the treatment of Staphylococcus aureus bacteremia: study protocol for a randomized controlled trial.

BACKGROUND: Staphylococcus aureus bacteremia is associated with significant morbidity and mortality. To treat this infection, the current standard of care includes intravenous anti-staphylococcal beta-lactam antibiotics and obtaining adequate source control. Combination therapy with an aminoglycoside or rifampin, despite early promise, can no longer be routinely recommended due to an absence of proven benefit and risk of harm. Daptomycin is a rapidly acting bactericidal antibiotic that is approved for the treatment of Staphylococcus aureus bacteremia as monotherapy but has not been shown to be superior to the current standard of care. As demonstrated in vitro, the addition of daptomycin to beta-lactam therapy may result in enhanced anti-staphylococcal activity. Our objective is to assess the efficacy and safety of prescribing the combination of daptomycin with cefazolin or cloxacillin for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia in adults. We hypothesize that adjunctive therapy with daptomycin will reduce the duration of bacteremia in this population. METHODS: The DASH-RCT trial is a randomized, double blind, placebo-controlled trial designed per the Standard Protocol Items: Recommendation for Interventional Trials (SPIRIT) and Consolidated Standards of Reporting Trials (CONSORT) guidelines. We recruit adults with confirmed MSSA bacteremia, at the McGill University Health Center. Patients are eligible if they are 18 years or older, can receive cefazolin or cloxacillin monotherapy, and are enrolled within 72 h of the first blood culture being drawn. Exclusion criteria include anaphylaxis to study drugs, having polymicrobial bacteremia, anticipated hospital admission for < 5 days, and healthcare team refusal. While receiving standard of care, study patients are randomized to a 5-day course of adjunctive daptomycin or placebo. The trial began in December 2016 and is expected to end in December 2018, after recruiting an estimated 102 patients. DISCUSSION: The DASH-RCT will compare the use of daptomycin as an adjunct to an anti-staphylococcal beta-lactam versus placebo in the treatment of MSSA bacteremia. We believe that a short course of dual therapy will result in earlier eradication of bacteremia and that subsequent research could evaluate effects on metastatic infection, relapse, and/or mortality. Ongoing issues in the trial include a delay between presentation of infection, enrollment in the trial, and the potential for unrecognized deep foci of infection at diagnosis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02972983 . Registered on 25 November 2016. Trial protocol: http://individual.utoronto.ca/leet/dash/dashprotocol.pdf.

Acute kidney injury during treatment with high-dose cloxacillin: a report of 23 cases and literature review.

BACKGROUND: International guidelines recommend high-dose cloxacillin for endocarditis or osteoarticular infections due to methicillin-susceptible staphylococci. However, data on the tolerability of these regimens are scarce. METHODS: We used the computerized registry of suspected drug-related adverse events in our institution. Cases of acute kidney injury (AKI), as defined by KDIGO, in patients receiving high-dose cloxacillin were retrospectively reviewed. Data were collected from medical charts on a standardized questionnaire. RESULTS: From 2009 to 2015, 23 consecutive patients (16 men, 7 women) with a median age of 75 years (interquartile range [IQR], 66-80) fulfilled inclusion criteria. By the time of AKI diagnosis, patients were treated with a median cloxacillin dose of 12 g/day (IQR, 10-12) after a median duration of 7 days (IQR, 4-10). Most patients (n=20) fulfilled RIFLE criteria for failure, with a median peak serum creatinine concentration of 339 µmol/L (IQR, 249-503). Urinalysis was indicative of tubular disease in 7 patients, 3 had hypereosinophilia and 8 had abnormal liver function tests. All patients presented at least one risk factor for AKI, including concomitant nephrotoxic drugs: gentamicin (n=19), diuretics (n=15), angiotensin-converting enzyme inhibitors (n=8) and angiotensin II receptor-blockers (n=6). Thirteen patients (57%) had cloxacillin plasma concentrations >50 µg/mL. Thirteen patients (57%) had complete recovery of renal function. CONCLUSIONS: AKI during high-dose cloxacillin treatment mostly occurs in elderly patients taking concomitant nephrotoxic drugs. The outcome is usually favourable after cloxacillin discontinuation. Therapeutic drug monitoring may decrease the risk of AKI in patients treated with high-dose cloxacillin.

Cloxacillin induced agranulocytosis: A rare adverse event of a commonly used antibiotic.

Cloxacillin, a semisynthetic penicillin is a potent inhibitor of most penicillinase-producing Staphylococci. Use of high doses of Cloxacillin for 6 weeks is recommended for the treatment of infective endocarditis caused by methicillin-susceptible Staphylococcus aureus (MSSA). Here, we report a case of Cloxacillin-induced agranulocytosis in a patient treated for MSSA native tricuspid valve endocarditis, which was resolved after discontinuation of the antibiotic. This case report highlights a rare adverse event of a commonly used antibiotic.

Cloxacillin: A New Cause of Pill-Induced Esophagitis.

A large variety of medications can cause pill-induced esophagitis. Herein we present a case of cloxacillin-induced esophagitis. A 66-year-old male presented with an acute onset of epigastric and retrosternal pain on the 5th day of a course of oral cloxacillin prescribed for erysipelas. Initial clinical and imaging assessment was negative and he was sent home. A few days later, he returned with persistent severe retrosternal pain; endoscopy at the same day revealed a normal upper esophagus, several small stellate erosions in the midesophagus, and a normal squamocolumnar junction with a small hiatus hernia. Treatment with esomeprazole 40 mg bid and Mucaine(R) suspension resulted in complete resolution of his symptoms. Pill-induced esophagitis may be underreported by patients, when symptoms are mild and unrecognized and/or underdiagnosed by the clinicians as a cause of retrosternal pain, odynophagia, or dysphagia. Failure of early recognition may result in unnecessary diagnostic investigations and prolongation of the patient's discomfort. This case signifies the importance of enhancing clinician awareness for drug-associated esophageal injury when assessing patients with retrosternal pain, as well as the value of prophylaxis against this unpleasant condition by universally recommending drinking enough water in an upright position during ingestion of any oral medication.

[Reinstating cloxacilin for empiric antibiotic in late-onset sepsis]. / Reposicionando la cloxacilina como antibioticoterapia empírica inicial de la sepsis tardía neonatal.

Vancomycin has been used for more than 50 years in neonatal intensive care units (NICUs) as the therapy of choice for late-onset sepsis, mainly because Coagulase negative Staphylococci (CoNS) are common and mostly resistant to oxacyllin despitelow virulence and unusual association with fulminant sepsis. CUs due to several factors including its high pharmacokinetic variability, difficulty in reaching therapeutic plasmatic drug concentrations and progressively increasing minimum inhibitory concentrations (MIC). The increase of CoNS with higher MICs as well as the rise of infections caused by resistant gram-negative bacilli and candida should move to reconsider Vancomycin as first line treatment. Infections in neonates have a different behavior than in other populations and we consoder of utmost importance to consider the use of oxacyllin as first line antimicrobial therapy for late-onset sepsis.

Reposicionando la cloxacilina como antibioticoterapia empírica inicial de la sepsis tardía neonatal / Reinstating cloxacilin for empiric antibiotic in late-onset sepsis

Vancomycin has been used for more than 50 years in neonatal intensive care units (NICUs) as the therapy of choice for late-onset sepsis, mainly because Coagulase negative Staphylococci (CoNS) are common and mostly resistant to oxacyllin despitelow virulence and unusual association with fulminant sepsis. CUs due to several factors including its high pharmacokinetic variability, difficulty in reaching therapeutic plasmatic drug concentrations and progressively increasing minimum inhibitory concentrations (MIC). The increase of CoNS with higher MICs as well as the rise of infections caused by resistant gram-negative bacilli and candida should move to reconsider Vancomycin as first line treatment. Infections in neonates have a different behavior than in other populations and we consoder of utmost importance to consider the use of oxacyllin as first line antimicrobial therapy for late-onset sepsis.

Vancomicina se utiliza hace más de 50 años en unidades de cuidados intensivos neonatales (UCIN) como terapia de elección en sospecha de sepsis neonatal tardía; su principal indicación se fundamenta en que Staphylococcus coagulasa negativa (SCN) es el principal microorganismo que ocasiona sepsis tardía y éste es habitualmente resistente a cloxacilina; sin embargo, su virulencia es baja y la sepsis fulminante es inusual. Lamentablemente la prescripción de vancomicina se ha convertido en un grave problema en las UCIN, debido a diversas razones incluyendo: alta variabilidad farmacocinética del fármaco, dificultad en alcanzar concentraciones plasmáticas apropiadas y aumento de la concentración inhibitoria mínima (CIM), implicando además una mayor probabilidad de seleccionar cepas resistentes y aumento de otro tipo de infecciones ocasionadas por bacilos gramnegativos resistentes y candidiasis invasora. Considerando lo anteriormente señalado y a lo publicado en la literatura médica con respecto a las infecciones en neonatología, debido a su comportamiento clínico diferente a hospederos en otras etapas de la vida, resulta de suma importancia replantear el uso de vancomicina basado en fundamentos teóricos que avalen la seguridad de no utilizar este antimicrobiano como primera línea en sepsis neonatal tardía.

Cloxacillin-induced seizure in a hemodialysis patient.

We are reporting a cloxacillin-induced seizure in a patient with stage 5 chronic kidney disease requiring hemodialysis. To our knowledge, there are no published case reports of seizures induced by parenteral cloxacillin in hemodialysis patients. A young hemodialysis female was admitted to the hospital with decreased level of consciousness. Blood cultures revealed methicillin-sensitive Staphylococcus aureus where cloxacillin 2 g intravenously every 4 hours was initiated. Head computed tomography (CT) was not significant. After 14 hours of cloxacillin therapy (4 doses), the patient demonstrated tonic/clonic seizure activity, where phenytoin and lorazepam were initiated. The anti-seizure medications partially reduced seizure activity. Once the cloxacillin was discontinued, the seizures stopped. Two weeks later, all anti-seizure medications were stopped with no further seizure activity. Cloxacillin elimination in hemodialysis patients is similar to patients with normal kidney function. Although cloxacillin does not significantly cross the blood-brain barrier, the correlation between the start of seizures and cloxacillin initiation was confirmed by the negative CT and blood chemistry laboratory results. Moreover, seizure activity was terminated upon discontinuation of cloxacillin. Although further investigation for the cause of such seizures is warranted, clinicians should use caution when giving high doses of cloxacillin in hemodialysis patients.

DRESS syndrome due to antibiotic therapy of osteoarticular infections in children: two case reports.

Osteoarticular infection in children frequently occurs before 10 years of age. Surgical drainage is sometimes required, whereas acute osteomyelitis can be treated with antibiotic therapy alone. The duration of antibiotic therapy varies, 2 weeks is sufficient for septic arthritis, whereas 6 weeks is often required for complicated cases. Some of these antibiotic drugs present direct complications with low clinical impact in certain individuals. Hypersensitivity to these drugs causes different reactions in children. DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms) is a severe and potentially life-threatening drug reaction. It is characterised by high fever, malaise, lymphadenopathy and skin rash. From a clinical perspective, these symptoms can lead to an exacerbation of the initial infectious process for which treatment was commenced. The liver is the organ most often affected in DRESS syndrome associated with haematological changes, potentially similar to sepsis. We present two cases of children with osteoarticular infections who developed DRESS syndrome after antibiotic therapy. Both patients made a complete recovery after cessation of the antibiotic drugs used.

A probable clinically significant interaction between warfarin and cloxacillin: three case reports.

CASES: Three patients were admitted to the Imam Hospital, Tehran, Iran with a diagnosis of bacterial endocarditis. The patients had indications for valve replacement surgery and anticoagulant therapy. The administration of cloxacillin reduced the effect of warfarin, and subsequent increases in warfarin doses were unable to overcome this effect. CONCLUSION: A decrease in warfarin anticoagulation effects was detected in our three patients following cloxacillin therapy for infective endocarditis. Penicillinase-resistant penicillins remain essential antibiotics in the treatment of severe infections caused by Staphylococcus aureus due to their bactericidal activity, safety, and cost. Thus, in situations where anticoagulants are indicated in patients with infective endocarditis, it would be better to replace warfarin with low-molecular-weight or unfractionated heparin.