Seventeen Cases of Daptomycin-Induced Eosinophilic Pneumonia in a Cohort of Patients Treated for Bone and Joint Infections: Proposal for a New Algorithm

Background: Daptomycin is increasingly used in the treatment of bone and joint infections (BJIs) and may be responsible for daptomycin-induced eosinophilic pneumonia (DIEP), a potentially severe adverse drug reaction. The aim of this study was to describe DIEP in patients treated at a referral center for the management of BJI, and to revisit current definitions of this disease.Methods: Patients treated from 1 January 2012 to 31 March 2021 were included in a prospective cohort (NCT02817711), in which all potential serious adverse events are prospectively recorded. Patients diagnosed with DIEP were retrospectively analyzed using different definitions.Results: In a total of 4664 patients included in the cohort during the study period, 1021 patients (21.9%) received daptomycin, of whom 17 (1.7%) were diagnosed with DIEP. Most patients were male (n = 11 [64.7%]), and periprosthetic joint infection was the commonest BJI (n = 12 [70.6%]). Only 1 patient had bronchoalveolar lavage (BAL) eosinophil count ≥25%, while most patients had peripheral blood eosinophilia (n = 15 [88.2%]). Chest computed tomography (CT) was compatible with eosinophilic pneumonia in 13 of 14 cases (92.9%). All patients recovered upon discontinuation of daptomycin. Using the different definitions available, only a minority of cases fulfilled existing criteria for DIEP. We propose a new algorithm that includes specific CT scan signs, and systemic instead of BAL eosinophilia.Conclusions: DIEP is a rare event that requires prompt discontinuation of the causative antibiotic. Current criteria to diagnose definite DIEP are too restrictive and not easily applicable in clinical practice. A new algorithm is proposed here (Lyon algorithm) to facilitate the early identification of DIEP

Correction of linezolid-induced myelotoxicity after switch to tedizolid in a patient requiring suppressive antimicrobial therapy for multidrug-resistant staphylococcus epidermidis prosthetic-joint infection

A 71-year-old man (85 kg) has a past history of vitiligo, ischemic myocardiopathy, and bilateral knee arthroplasties. A 1-stage exchange of the right prosthetic-joint infection (PJI) was done in 2016 for a mechanical prosthetic loosening. A massive constrained prosthetic joint was used to compensate for the bone loss (Supplementary Figure S1A). Iterative postoperative dislocations were followed by occurrence of a fistula in January 2017 and prosthetic loosening (Supplementary Figure S1B) without any pain. Because it was impossible to imagine a 2-stage exchange, a debridement and implant retention (DAIR) procedure followed by suppressive antimicrobial therapy was proposed. Daptomycin (700 mg/day) and ceftaroline (1200 mg/ day) were prescribed after the surgery. A multidrug-resistant Staphylococcus epidermidis, which is only susceptible to dap-tomycin, vancomycin, fosfomycin, and linezolid, was found in culture from all operative samples. After 6 weeks of intravenous antimicrobial therapy, 600 mg of linezolid bid was prescribed in August 2017. Concomitant medications were ramipril, bisopr-olol, furosemide, and aspirin. Under therapy, the patient experienced a progressive decrease of hemoglobin and hematocrit (without decrease of white blood cells or platelets). Five months after linezolid introduction, the patient developed asthenia related to anemia, with a decrease of hemoglobin to 65 mg/dL, and without leucopenia or thrombocytopenia (Figure 1). The patient did not take any treatment with potential bone marrow toxicity, except linezolid. The patient has no other adverse drug reactions. A blood transfusion (2 bags) was performed, which led to an immediate increase of the hemoglobin level to 84 mg/ dL, and linezolid was switched to 200 mg of tedizolid once a day. In May 2018, 9 months after the DAIR surgery and 4 months after the switch, the patient was perfectly fine, walked despite rupture of the right knee extensor apparatus (video S2), without any pain, without any local signs of relapse (Supplementary Figure S1C), without clinical signs of neuropathy, and he experienced a continuous increase of the hemoglobin to 14 mg/dL under tedizolid therapy. No other treatment was changed or introduced

Population pharmacokinetics of daptomycin in patients with bone and joint infection: minimal effect of rifampicin co-administration and confirmation of a sex difference

International audienceBackground Daptomycin is increasingly used in the treatment of bone and joint infection (BJI), but its pharmacokinetics (PK) and dosage requirements have not been thoroughly investigated in this indication. Daptomycin may be co-administered with rifampicin, which raises questions about a potential drug interaction. Objectives To investigate the population PK and dosage requirements of daptomycin in patients with BJI, and examine the influence of rifampicin co-administration. Methods A population approach was used to analyse PK data from patients who received daptomycin in our regional reference for BJI. We examined the influence of available covariates, including rifampicin co-administration on daptomycin PK. Simulations performed with the final model investigated the influence of dosages and covariates on PTA for both efficacy and safety. Results A total of 1303 daptomycin concentrations from 183 patients were analysed. A two-compartment model best described the data. Significant intra-individual variability was observed. Daptomycin clearance was influenced by renal function and sex, with females having a 26% lower typical clearance than males. Central volume of distribution (V1) was influenced by body weight, age, sex and rifampicin co-administration. Typical V1 was 11% lower in patients who were co-administered rifampicin. In PK/PD simulations, sex influenced the probability of AUC24/MIC target attainment, while rifampicin had a marginal effect. Conclusions A daptomycin dosage of 8 mg/kg/24 h in women and 10 mg/kg/24 h in men should optimize efficacy but may lead to excessive trough concentrations in many patients, especially in women. Therapeutic drug monitoring appears necessary for precision dosing of daptomycin

Coxiella burnetti prosthetic joint infection in an immunocompromised woman: iterative surgeries, prolonged ofloxacin-rifampin treatment and complex reconstruction were needed for the cure

International audienceAbstract Background Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii , a strictly intracellular pathogen that can cause acute and chronic infection. Chronic Q fever can occur in immunocompetent as well as in immuno-compromised hosts, as a persistent localized infection. The main localizations are endocardial, vascular and, less frequently, osteoarticular. The most frequent osteoarticular form is spondyliscitis. Recommended treatment is combined doxycycline and hydroxychloroquine for 18 months, with cotrimoxazole as another option. Coxiella burnetti infection has been implicated in rare cases of prosthetic joint infection (PJI), and the medical and surgical management and outcome in such cases have been little reported. Case presentation We report an unusual case of chronic Q fever involving a hip arthroplasty in an immunocompromised woman treated with tumor necrosis factor (TNF)-α blockers for rheumatoid arthritis. Numerous surgical procedures (explantation, “second look”, femoral resection and revision by megaprosthesis), modification of the immunosuppressant therapy and switch from doxycycline-hydroxychloroquine to prolonged ofloxacin-rifampin combination therapy were needed to achieve reconstruction and treat the PJI, with a follow-up of 7 years. Conclusions Coxiella burnetti PJI is a complex infection that requires dedicated management in an experienced reference center. Combined use of ofloxacin-rifampin can be effective

Necrotizing external otitis: analysis of relapse risk factors in 66 patients managed during a 12 year period

International audienceAbstract Background Necrotizing external otitis (NEO) is a severe infection of the skull base that occurs generally in the elderly and/or in diabetic recipients. There are few data in the literature about the therapeutic management of this complex bone infection. Objectives To analyse relapses after NEO treatment completion, and to describe the clinical features of NEO. Methods We performed a retrospective cohort study in the Lyon regional reference centre for the management of complex bone and joint infections. Consecutive cases of NEO from 1 January 2006 to 31 December 2018 were included. The primary outcome was the relapse of NEO. Variables were analysed using Cox regression survival analysis with adjusted hazard ratio (aHR) and Kaplan–Meier curve. Results Sixty-six patients were included. Median age was 75 (IQR 69–81) years and 46 (70%) patients were diabetic. Eleven patients (17%) had temporomandibular arthritis, 10 (15%) cranial nerve paralysis, 2 (3%) cerebral thrombophlebitis, and 2 (3%) contiguous abscess. Microbiological documentation was obtained in 56 patients and revealed Pseudomonas aeruginosa in 44/56 patients (79%). Nine (14%) cases had no microbiological documentation. Antibiotic therapy was dual for 63 (95%) patients. During a median follow-up of 27 (IQR 12–40) months, 16 out of 63 (25%) patients experienced a relapse. Fungal infection was significantly associated with relapse [aHR 4.1 (95% CI 1.1–15); P = 0.03]. Conclusions NEO is a severe bone infection, mainly (but not exclusively) caused by P. aeruginosa, which occurs in elderly and diabetic recipients. Fungal infections at baseline significantly impact the outcome

Evaluation of intraosteoblastic activity of dalbavancin against Staphylococcus aureus in an ex vivo model of bone cell infection

International audienceAbstract Objectives Long-acting lipoglycopeptides are promising therapeutic options in Staphylococcus aureus bone and joint infections (BJIs). This study evaluated the ability of dalbavancin to eradicate the intraosteoblastic reservoir of S. aureus, associated with BJI chronicity. Methods Osteoblastic cells were infected with a standardized inoculum of the S. aureus reference strain HG001 and incubated for 24 h with dalbavancin, vancomycin or rifampicin using the MIC, 10×MIC, 100×MIC and/or the intraosseous concentrations reached using standard therapeutic doses (i.e. vancomycin, 10 mg/L; rifampicin, 2 mg/L; and dalbavancin, 6 mg/L). The remaining intracellular bacteria were quantified by plating cell lysates. Results MICs of dalbavancin, vancomycin and rifampicin were 0.125, 1 and 0.004 mg/L, respectively. Dalbavancin significantly reduced the intracellular inoculum of S. aureus starting at a concentration equal to the MIC, with a significant dose effect, ranging from a reduction of 31.4% (95% CI = 17.6%–45.2%) at MIC to 51.6% (95% CI = 39.8%–63.4%) at 100×MIC compared with untreated cells. Of note, dalbavancin was the only molecule to significantly reduce the intraosteoblastic inoculum at low concentration (MIC). At intraosseous concentrations, dalbavancin reduced the intracellular inoculum by 49.6% (95% CI = 45.1%–54.1%) compared with untreated cells (P < 0.001), with no significant difference compared with vancomycin (38.1%; 95% CI = 19.2%–57.0%; P = 0.646), and was less efficient than rifampicin (69.0%; 95% CI = 63.2-74.8; P < 0.001). Conclusions Dalbavancin was able to decrease the intraosteoblastic S. aureus inoculum by 50% at intraosseous concentrations reached during standard human therapeutic dosing, with no difference compared with vancomycin, and remained less efficient than rifampicin. However, it was the only molecule significantly active at low concentration