Myelosuppression-sparing treatment of central nervous system nocardiosis in a multiple myeloma patient utilizing a tedizolid-based regimen: a case report

In vitro activity of tedizolid against 43 species of Nocardia species

The purpose of the present study was to evaluate the in vitro activity of tedizolid against several clinically significant species of Nocardia by comparing with that of linezolid. A total of 286 isolates of Nocardia species, including 236 clinical isolates recovered from patients in Japan and 50 strains (43 species) purchased from NITE Biological Resource Center, were studied. Antimicrobial susceptibility testing was performed using the broth microdilution method. For the 286 Nocardia isolates, the minimal inhibitory concentration (MIC)50 and MIC90 values of tedizolid were 0.25 and 0.5 μg/ml, and those of linezolid were 2 and 2 μg/ml, respectively. The distribution of the linezolid/tedizolid ratios (MICs of linezolid/MICs of tedizolid) showed that tedizolid had four- to eight-fold higher activity than linezolid in 96.1% (275/286) of Nocardia isolates. Both the tedizolid and linezolid MIC90 values for Nocardia brasiliensis were two-fold higher than those for the other Nocardia species. Both tedizolid and linezolid had low MIC values, 0.25-1 μg/ml and 0.5-4 μg/ml, respectively, even against nine isolates (five species) that were resistant to trimethoprim/sulfamethoxazole. One Nocardia sputorum isolate showed reduced susceptibility to tedizolid (4 μg/ml). Bioinformatics analysis suggests different resistance mechanisms than the oxazolidinone resistance seen in enterococci and staphylococci.

Disseminated nocardiosis with persistent neurological disease

A man in his 80s with a history of sarcoidosis on chronic prednisone presented to the emergency department with several days of dyspnoea. A chest X-ray showed signs of pneumonia, and the patient was admitted. Blood and pleural fluid cultures grew Nocardia farcinica; therefore, the patient was started on treatment with trimethoprim-sulbactam and imipenem. Brain imaging showed evidence of dissemination of the infection to the central nervous system (CNS). The patient's admission was complicated by pleural effusions, acute kidney injury and pancytopenia, and therefore, his antibiotic regimen was ultimately transitioned from trimethoprim-sulfamethoxazole (TMP-SMX), meropenem and linezolid to imipenem and tedizolid. The patient received imipenem and tedizolid for the remainder of the admission. A repeat MRI of the brain was performed after 6 weeks of this dual antibiotic therapy, which unfortunately revealed persistent CNS disease. His regimen was then broadened to TMP-SMX, linezolid and imipenem. Despite these measures, however, the patient ultimately passed away from the infection.

A pharmacokinetic-pharmacodynamic (PKPD) model-based analysis of tedizolid against enterococci using the hollow-fibre infection model

BACKGROUND

Tedizolid is a novel oxazolidinone antibiotic. Considering the higher antibacterial effect in immunocompetent compared with immunosuppressed animals, it is not recommended in immunocompromised patients.

OBJECTIVES

In this study, we assessed the 'pure' pharmacokinetic-pharmacodynamic (PKPD) relationship for tedizolid against Enterococcus in the hollow-fibre infection model (HFIM).

METHODS

Unbound plasma concentration time profiles (200-5000 mg/day IV) were simulated in the HFIM over 120 h against an Enterococcus faecalis strain and two clinical isolates of Enterococcus faecium (VRE-vanB and VRE-vanA). Next, a PKPD model describing tedizolid efficacy against bacterial isolates was developed. A population PK model was linked to the developed PKPD model and utilized to predict the bacterial kinetics in plasma and in target tissues [adipose, muscle, epithelial lining fluid (ELF) and sputum] over 120 h of therapy.

RESULTS

The PKPD model adequately described the bacterial kill kinetics for all bacterial populations. At the human recommended dose of 200 mg/day, bacterial growth was predicted in plasma and all tissues, except for ELF. Bacteriostasis was observed only at a higher dose of 1200 mg/day over 120 h. An fAUC/MIC of 80 related to stasis over 120 h. Subpopulations resistant to 3 × MIC were amplified in plasma and target tissues, except for ELF, at doses of 200-800 mg/day.

CONCLUSIONS

The human dose of 200 mg/day was insufficient to suppress bacterial growth in the HFIM, indicating that further components contribute to the clinical effect of tedizolid. This study supports the warning/precaution for tedizolid to limit its use in immunocompromised patients.

Long-term use of tedizolid for pulmonary nocardiosis

Nocardiosis usually occurs in immunocompromised patients and causes infections in various organs, including the lungs, skin, and organs of the central nervous system. Herein, we report the case of a patient with minimal change nephrotic syndrome who had been on immunosuppressive drugs and developed pulmonary nocardiosis due to Nocardia nova complex and Pneumocystis pneumonia. For pulmonary nocardiosis, trimethoprim-sulfamethoxazole, linezolid, and clarithromycin were initiated sequentially, but were subsequently discontinued due to side effects; the treatment was completed with tedizolid. Tedizolid was used safely for 200 out of 286 days of antibiotic treatment, and clinical improvement was observed. Tedizolid is a bacteriostatic oxazolidine antibiotic that inhibits bacterial protein synthesis, the same mechanism as its predecessor, linezolid. Tedizolid is thought to cause less frequent myelosuppression than linezolid, at least for short-term use. In the future, tedizolid may be a promising alternative to linezolid in cases of nocardiosis that usually require long-term treatment.

Nocardia farcinica Brain Abscess in a Multiple Myeloma Patient Treated with Proteasome Inhibitor: A Case Report and Review of the Literature

Nocardia brain abscess is relatively rare, accounting for about 1–2% of all brain abscesses, and its mortality rate is three times higher than of other types of bacterial brain abscesses; thus, early diagnosis and treatment are essential. Nocardia brain abscess generally occurs in immunodeficient patients. We report a case of Nocardia farcinica brain abscess in a multiple myeloma patient treated with proteasome inhibitor (bortezomib and ixazomib), cyclophosphamide, and corticosteroid. The patient was treated with ceftriaxone and trimethoprim-sulfamethoxazole, together with drainage of the brain abscess. Regular brain MRI follow-ups showed that intracranial lesions were gradually absorbed and improved.

Safety of Tedizolid as Suppressive Antimicrobial Therapy for Patients With Complex Implant-Associated Bone and Joint Infection due to Multidrug-Resistant Gram-Positive Pathogens: Results From the TediSAT Cohort Study

A prospective cohort study was conducted to evaluate long-term safety of tedizolid as suppressive antimicrobial treatment in patients with implant-associated bone and joint infection caused by multidrug-resistant gram-positive pathogens. Seventeen patients received tedizolid with a median duration of treatment of 6 months. No patients developed a serious adverse event.

Tedizolid (torezolid) for the treatment of complicated skin and skin structure infections

INTRODUCTION

Acute bacterial skin and skin structure infections (ABSSSI) are among the most frequent infectious diseases. Recently, several new antibiotics with activity against MRSA have been approved. Tedizolid, a second-generation oxazolidinone approved for ABSSSI offers theoretical advantages over first-generation oxazolidinones.

AREAS COVERED

A comprehensive online search of Medline, ClinicalTrials.gov, and conference presentations was made, selecting articles between January 2000 and April 2020. In this review, the authors discuss the chemical and microbiological properties of tedizolid, summarize its efficacy, safety, and potential role in the treatment of ABSSSI as well as the potential for future indications.

EXPERT OPINION

Tedizolid has proven to be non-inferior compared to linezolid for the treatment of ABSSSI in two registrational phase III clinical trials, being well tolerated. Tedizolid exhibits antibacterial activity against the most important ABSSSI pathogens (including multidrug-resistant strains of MRSA), as well as mycobacteria and Nocardia. It appears to have a safe profile, including decreased myelotoxicity and no significant drug interactions. Preliminary studies with longer duration of therapy seem to confirm these potential benefits. Overall, tedizolid expands the newly acquired armamentarium to treat ABSSSI. The role of tedizolid for other indications is under investigation and has yet to be determined.

The role of tedizolid in skin and soft tissue infections

PURPOSE OF REVIEW

Tedizolid is a second-generation oxazolidinone with activity against Gram-positive bacteria, including MRSA isolates resistant to linezolid. Pivotal clinical trials showed that tedizolid at 200 mg once-daily for 6 days is not inferior to linezolid 600 mg twice daily for 10 days in patients with SSTI. The comparison of adverse events is favorable to tedizolid under the circumstances of the clinical trials. This is a review of recent literature on tedizolid, its use in special populations and potential adverse effects.

RECENT FINDINGS

Findings suggest that tedizolid can be used in SSTI in adolescents, those older than 65 years, obese individuals and patients with diabetic foot infections. Forthcoming research to determine the future uses of this drug in other clinical syndromes requires demonstration of tolerance whenever tedizolid is administered for longer than 6 days.We also speculate on missing data and potential future indications of tedizolid in the highly competitive field of the treatment of severe Gram-positive infections other than SSTI.

SUMMARY

Tedizolid is a second-generation oxazolidinone, very convenient for treatment of SSTI, in search for other indications including nosocomial pneumonia and bone and joint infections. VIDEO ABSTRACT.

Tedizolid phosphate for the treatment of acute bacterial skin and skin-structure infections: an evidence-based review of its place in therapy

Introduction

Tedizolid phosphate is an oxazolidinone approved for the treatment of acute bacterial skin and skin-structure infections (ABSSSIs) and active against methicillin-resistant Staphylococcus aureus.

Aims

The objective of this article was to review the evidence for the efficacy and safety of tedizolid phosphate for the treatment of ABSSSI.

Evidence review

Approval of tedizolid phosphate for the treatment of ABSSSI was based on the results of two phase III randomized controlled trials, ESTABLISH-1 (NCT01170221) and ESTABLISH-2 (NCT01421511), comparing 6-day once-daily tedizolid vs 10-day twice-daily linezolid. In ESTABLISH-1, noninferiority was met with early clinical response rates of 79.5% and 79.4% in tedizolid and linezolid groups, respectively (difference 0.1%, 95% CI –6.1% to 6.2%, with a 10% noninferiority margin). In ESTABLISH-2, noninferiority was met with 85% and 83% rates of early clinical response in tedizolid and linezolid groups, respectively (difference 2.6%, 95% CI –3.0% to 8.2%). Pooled data from ESTABLISH-1 and ESTABLISH-2 indicated a lower frequency of thrombocytopenia in tedizolid-treated than in linezolid-treated patients.

Conclusion

Tedizolid offers the option of an intravenous to oral switch, allows once-daily administration, and presents lower risk of myelotoxicity when a 6-day course is used for the treatment of ABSSSI. Greater economic cost associated with this antibiotic could be offset by its shorter treatment duration and possibility of oral administration in routine clinical practice, although either sponsored or nonsponsored postmarketing observational experience remains essential for ultimately confirming the effectiveness and tolerability of tedizolid outside clinical trials.

Nocardia infections in solid organ transplantation: Guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of Nocardia infections after solid organ transplantation (SOT). Nocardia infections have increased in the last two decades, likely due to improved detection and identification methods and an expanding immunocompromised population. The risk of developing nocardiosis after transplantation varies with the type of organ transplanted and the immunosuppression regimen used. Nocardia infection most commonly involves the lung. Disseminated infection can occur, with spread to the bloodstream, skin, or central nervous system. Early recognition of the infection and initial appropriate treatment is important to achieve good outcomes. Species identification and antimicrobial susceptibility testing are strongly recommended, as inter- and intraspecies susceptibility patterns can vary. Sulfonamide is the first-line treatment of Nocardia infections, and combination therapy with at least two antimicrobial agents should be used initially for disseminated or severe nocardiosis. Trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis may be helpful in preventing Nocardia infection after SOT.

Advances in pediatric antimicrobial agents development

PURPOSE OF REVIEW

Rising rates of multidrug-resistant organisms has necessitated the development of novel antimicrobials. In this review, we will highlight agents that have recently received licensure and those that are in clinical development.

RECENT FINDINGS

In recent years, development of novel antimicrobial agents has accelerated. Although most studies have targeted the adult population, studies in pediatric patients are underway. Adequately powered clinical trials are needed to establish the safety and role of these new drugs.

SUMMARY

The recent development of novel antimicrobials to combat multidrug-resistant organisms is encouraging; however, more studies in the pediatric population are needed.

Nocardia infections in solid organ and hematopoietic stem cell transplant recipients

PURPOSE OF REVIEW

Nocardia spp. is a gram-positive bacteria that may cause infections in humans. Nocardiosis has been described since the early years of transplantation. This review aims to provide an overview of present knowledge regarding posttransplant nocardiosis, with a focus on recent findings.

RECENT FINDINGS

Nocardiosis is not rare among transplant recipients, especially after thoracic transplantation and/or in case of intense immunosuppressive regimen or use of tacrolimus. Low-dose cotrimoxazole is not effective to prevent nocardiosis. Although lung is the most common site of infection, more than 40% of organ transplant patients have a disseminated infection. As central nervous system involvement is frequent (about 1/3 of the patients) and possibly asymptomatic, brain imaging is mandatory. Diagnosis relies on direct examination and culture; molecular species identification is useful to guide treatment. Although cotrimoxazole is the drug for which we have the strongest clinical experience, other antibiotics such as linezolid, parenteral cephalosporins, carbapenems, and amikacin can be used to treat nocardiosis. Although treatment duration has historically been set to at least 6 months, shorter durations (<120 days) seem associated with a good outcome in selected patients.

SUMMARY

Physicians in charge of transplant patients should be aware of nocardiosis. Diagnosis and management of transplant recipients with nocardiosis require a multidisciplinary approach.

Nocardia farcinica Brain Abscess: Report of 3 Cases

BACKGROUND

Central nervous system nocardial infection is a rarely reported disease that usually affects patients with predisposing and debilitating conditions but also the immunocompetent population. The most common variant affecting the brain is Nocardia farcinica. Management of brain nocardiosis is troublesome and requires consideration of the severity of the underlying systemic disease, the difficulties in identifying the bacterium, and the frequent delay in initiating adequate therapy.

CASE DESCRIPTION

We present 3 cases of N. farcinica brain abscess (single, multiloculated, and multifocal) diagnosed in 3 patients with predisposing factors that could be successfully cured. The patients underwent craniotomy, evacuation of the purulent collection, and partial resection of the abscesses' walls. Confirmation of N. farcinica species was achieved using specific polymerase chain reaction sequencing of the 16S ribosome RNA gene. Antibiotic therapy was selected on susceptibility tests and was maintained for 10 months (1 case) and 12 months (2 cases).

CONCLUSIONS

Brain nocardiosis needs to be suspected primarily (though not exclusively) in immunocompromised patients presenting with neurologic deficit and harboring intracerebral lesions resembling brain tumors. Early identification of the specific species is paramount in order to initiate long-term antibiotic therapy, acknowledging the inherent resistance of N. farcinica to third-generation cefalosporins and its susceptibility to trimethoprim-sulphamethoxazole. According to the literature, surgical excision or aspiration of the brain abscess seems to provide good chances of eradication of the disease. In our experience, successful outcome was achieved with subtotal resection and prolonged and adequate antibiotic therapy.