Linezolid interaction with serotonin reuptake inhibitors: report of two cases and incidence assessment

The Association of Serotonin Toxicity with Combination Linezolid-Serotonergic Agent Therapy: A Systematic Review and Meta-Analysis

Linezolid (LZD) has a longstanding reported association with the onset of serotonin toxicity (ST), secondary to drug-drug interactions with serotoninergic agents. There have been no conclusive data supporting the incidence or contributing risk factors to date. The study evaluated the incidence of ST in patients treated with LZD and serotonergic agents concomitantly versus LZD alone. The secondary objectives included a comparison of ST incidence in patients treated with one serotonergic agent + LZD versus two or more serotonergic agents + LZD. The studies used for this meta-analysis were retrieved from PubMed, Scopus, and Google Scholar. All studies including a comparison between LZD alone and LZD + a serotonergic agent published between 1 January 2000 and 1 October 2023 and meeting the quality standards were considered for inclusion. Fourteen studies were identified, with five meeting all inclusion and exclusion criteria with no significant heterogeneity. For the analysis of LZD monotherapy vs. SA combination therapy, four studies with 6025 patients total were analyzed and yielded an odds ratio of 1.78 (CI [1.04, 3.02]; I2 = 49%; GRADE certainty: low). Four studies and 2501 patients were included in the analysis of one versus more than one SA with an odds ratio of 5.18 (CI [1.05, 25.49]; I2 = 44.87; GRADE certainty: moderate). The Newcastle-Ottawa score, visual inspection of the funnel plot, and Egger's statistic were used to evaluate quality and heterogeneity. The Peto method was used to calculate the summary odds ratios. All analyses were performed using Comprehensive Meta-Analysis version 3.0 and R, while GRADE was used to evaluate the quality of the final recommendation. The number of concomitant serotonergic agents may play a role in the development of serotonin toxicity in patients prescribed linezolid. In patients requiring linezolid therapy and serotonergic agents, risk versus benefit analysis should pay attention to the number of interacting drugs.

Linezolid-associated serotonin toxicity: a systematic review

PURPOSE

This systematic review aims to evaluate the existing evidence associating linezolid to serotonin toxicity when used as monotherapy or when co-administered with other serotonergic agents.

METHODS

A systematic literature search using PubMed (till March 2023), IDWeek meetings (2003-2023), the European Congress of Clinical Microbiology and Infectious Disease Annual Meetings (2001-2023), and the American College of Clinical Pharmacy (1999-2023) identified studies and abstracts related to linezolid and serotonin toxicity.

RESULTS

A total of 84 studies were included. The data collected in retrospective/observational studies compared the incidence of serotonin toxicity with linezolid monotherapy at 0.0050% and linezolid combination therapy at 0.0134%. All cases which discontinued linezolid and serotonergic agent/s at signs and symptoms of toxicity found symptom resolution; 75% of cases reported serotonin toxicity resolution within 24-48 h after discontinuation.

CONCLUSION

Linezolid therapy when optimal should not be deferred due to the risk of serotonin syndrome. The data collected reveals a low prevalence of serotonin toxicity in both linezolid monotherapy and linezolid concurrent with other serotonergic agents.

Real-World Use of Oritavancin for the Treatment of Osteomyelitis

Osteomyelitis is a difficult-to-treat disease that can require both surgical debridement and a prolonged course of antimicrobial therapy. Current standard of care for the antimicrobial treatment of osteomyelitis is fraught with multiple challenges and limitations. Patients typically require the insertion of an indwelling catheter for single or multiple daily intravenous antibiotic infusions for up to 6 weeks. Currently, there are treatment guidelines for only vertebral osteomyelitis, indicating the complexity of the condition. Oritavancin is a long-acting, second-generation lipoglycopeptide, administered intravenously once per week, which has potential to be a useful alternative in the treatment of osteomyelitis. This article reviews occurrence and outcomes of off-label oritavancin use for treatment of osteomyelitis as described in case reports. Analysis included 23 patients treated for osteomyelitis with single- or multiple-dose oritavancin. Overall, clinical cure or improvement was achieved in 87% of patients, and adverse events were mild and reported in only two patients. Clinical efficacy was demonstrated in 81.8% of methicillin-resistant Staphylococcus aureus (MRSA), 71.4% of methicillin-sensitive S. aureus (MSSA), 50% of vancomycin-resistant Enterococcus (VRE), and in the single case of Streptococcus pyogenes. Oritavancin has shown efficacy against Gram-positive pathogens in osteomyelitis, and offers a possible outpatient treatment option for osteomyelitis patients. Future studies are needed to determine dosing frequency in osteomyelitis patients.

Emerging drugs for treating methicillin-resistant Staphylococcus aureus

Introduction: In clinical practice, methicillin-resistant Staphylococcus aureus (MRSA) represents a major threat and has been associated with high rates of inadequate antibiotic treatment and significant increases in morbidity, mortality, and overall healthcare costs. The association between the prescription of an inappropriate or delayed antibiotic and impaired clinical outcomes has been widely described. Areas covered: To address the threat of MRSA, many new therapeutic options with a peculiar activity against MRSA have been recently developed and approved. New agents are characterized by specific issues in terms of spectrum of activity, pharmacokinetics, risk of drug-drug interactions, and toxicity, with potential advantages that should be considered in everyday clinical practice. Expert opinion: The most attractive characteristic of new drugs is represented by the broad spectrum of activity against multidrug-resistant pathogens; moreover, new compounds in most cases are characterized by favorable toxicity profiles compared with old drugs currently used in clinical practice. Some of the new antimicrobials will be also available as oral formulations, with the potential for oral switch, even in infections due to resistant pathogens. In particular conditions/populations (e.g. liver failure, renal disease, pregnancy, diabetic, children, and elderly), novel antibiotics with reduced toxicity could be an important option, including after hospital discharge.

Management of severe arterial hypertension associated with serotonin syndrome: a case report analysis based on systematic review techniques

Serotonin syndrome is thought to arise from serotonin excess. In many cases, symptoms are mild and self-limiting. But serotonin syndrome can become life threatening, when neuromuscular hyperexcitability spins out of control. Uncontainable neuromuscular hyperexcitability may lead to cardiovascular complications, linked to extreme changes in blood pressure. Currently, there is little guidance on how to control blood pressure in hyperserotonergic states. We report a case with treatment-resistant arterial hypertension, followed by a clinical review (using systematic review principles and techniques) of the available evidence from case reports published between 2004 and 2016 to identify measures to control arterial hypertension associated with serotonin syndrome. We conclude that classic antihypertensives may not be effective for the treatment of severe hypertension associated with serotonin syndrome. Benzodiazepines may lower blood pressure. Patients with severe hypertension not responding to benzodiazepines may benefit from cyproheptadine, propofol or both. In severe cases, higher cyproheptadine doses than currently recommended may be necessary.

Linezolid-associated serotonin toxicity after escitalopram discontinuation: concomitant drug considerations

We report a case of a hospitalised patient who developed probable serotonin toxicity shortly after the initiation of linezolid in whom the selective serotonin reuptake inhibitor (SSRI) escitalopram had been recently discontinued. On day 2 of linezolid administration, the patient reported severe anxiety and was observed to have full body jerking and twitching motions without mental status change. Notably, the patient was concomitantly receiving the antidepressant, trazodone and the benzodiazepine, clonazepam possibly affecting the severity and manifestations of serotonin toxicity. Linezolid was discontinued after 5 days and the patient's symptoms resolved. Serotonin toxicity can present with an array of symptoms and be life threatening if left unrecognised. This report highlights the clinical lessons that discontinuation of an SSRI upon initiation of linezolid does not eliminate the risk of serotonin toxicity and that other concomitant medications may worsen or improve some of the symptoms lending delay and uncertainty to the diagnosis.

The role of methicillin-resistant Staphylococcus aureus in skin and soft tissue infections

PURPOSE OF REVIEW

Methicillin-resistant Staphylococcus aureus (MRSA) has become a major public health issue worldwide over the last years. MRSA is frequently implicated in the development of skin and soft tissue infections, leading to significant increases in morbidity, mortality and overall healthcare costs.

RECENT FINDINGS

In order to face the threat of MRSA, major changes in clinical management of skin and soft tissue infections are required. The identification of populations at risk for the acquisition of infections due to MRSA, together with the improvement of the diagnostic techniques, is paramount. Moreover, a number of new antimicrobials with activity against MRSA have been recently developed and approved for the treatment of skin and soft tissue infections, however, the use of the new drugs in the wide clinical practice remains limited.

SUMMARY

We reviewed the current epidemiology of MRSA in skin and soft tissue infections, with particular focus on implications for clinical management. The potential role of new antibiotic options against MRSA infections is also discussed.

Linezolid in the treatment of drug-resistant tuberculosis: the challenge of its narrow therapeutic index

INTRODUCTION

Linezolid is an oxazolidinone with potent activity against M tuberculosis, and improves culture conversion and cure rates when added to treatment regimens for drug resistant tuberculosis. However, linezolid has a narrow therapeutic window, and the optimal dosing strategy that minimizes the substantial toxicity associated with linezolid's prolonged use in tuberculosis treatment has not been determined, limiting the potential impact of this anti-mycobacterial agent.

AREAS COVERED

This paper aims to review and summarize the current knowledge on linezolid for the treatment of drug-resistant tuberculosis. The focus is on the pharmacokinetic-pharmacodynamic determinants of linezolid's efficacy and toxicity in tuberculosis, and how this relates to defining an optimal dose. Mechanisms of linezolid toxicity and resistance, and the potential role of therapeutic drug monitoring are also covered. Expert commentary: Prospective pharmacokinetic-pharmacodynamic studies are required to define optimal therapeutic targets and to inform improved linezolid dosing strategies for drug-resistant tuberculosis.

Síndrome serotoninérgico en anciano con falla renal crónica tratada con linezolid: reporte de caso

<p>El síndrome serotoninérgico es una reacción adversa y potencialmente mortal a medicamentos; está caracterizado por cambios en el estado mental, hiperactividad autonómica y anormalidades músculo-esqueléticas causadas por exceso de serotonina a nivel central. Se reporta el caso de un paciente de 71 años con enfermedad renal crónica estadio V y cuadro clínico de infección intraabdominal asociada al catéter. Luego de 33 días de la hospitalización presentó temblor en manos, hiperreflexia y taquicardia. Al día 36 se tornó confuso, desorientado e incoherente, con palpitaciones y disneico. Entre los factores de riesgo para desarrollo de síndrome serotoninérgico se encuentra el uso de linezolid, que en combinación de otros medicamentos con acción serotoninérgica —como los inhibidores selectivos de recaptación de serotonina, el litio, la trazodona, entre otros— se asocia con la presentación de este cuadro. El síndrome serotoninérgico puede ser evitado con una buena educación al personal médico y la modificación de las conductas de prescripción de medicamentos; el pilar del tratamiento se basa en la suspensión de los fármacos que están causando el cuadro y el planteamiento de medidas de soporte.</p>

Serotonergic and Adrenergic Drug Interactions Associated with Linezolid: A Critical Review and Practical Management Approach

OBJECTIVE

To describe the evidence for serotonergic and adrenergic drug interactions with linezolid and discuss clinical management strategies.

DATA SOURCES

A literature search of PubMed (1947–November 2012), MEDLINE (1946–November 2012), EMBASE (1974–November 2012), and International Pharmaceutical Abstracts (1970–November 2012) was conducted using the terms linezolid, drug interaction, serotonin syndrome, serotonin toxicity, sympathomimetic, serotonergic agents, and adrenergic agents. Citations of retrieved articles were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

English-language articles describing coadministration of serotonergic or adrenergic agents with linezolid to humans were included. Studies published only in abstract form were excluded.

DATA SYNTHESIS

One prospective study, 6 retrospective studies, and 24 case reports were identified describing a serotonergic or adrenergic drug interaction. Incidence of serotonin syndrome in patients on linezolid and serotonergic agents ranged between 0.24% and 4%. Serotonergic agents determined to have probable (according to the Horn Drug Interaction Probability Scale) linezolid interactions in case reports included meperidine, citalopram, escitalopram, fluoxetine, paroxetine, sertraline, duloxetine, and venlafaxine. Serotonergic agent dose and duration of coadministration with linezolid did not appear to influence the occurrence of serotonin syndrome. Adrenergic medication coadministration was associated with a possible drug interaction as determined by the Horn Drug Interaction Probability Scale but did not appear to result in clinically significant drug interactions with linezolid.

CONCLUSIONS

Linezolid-associated serotonergic drug interactions occur more commonly than adrenergic interactions. Serotonergic interactions considered probable according to the Horn Drug Interaction Probability Scale do not appear to correlate with drug dosage; time of onset ranges from <1 to 20 days, and effect resolves in <1 to 5 days after discontinuation of offending agents. If coadministration of linezolid and a serotonergic agent cannot be avoided, clinicians should be aware of the symptoms and management of serotonergic toxicity; close monitoring is recommended and additional serotonergic agents should not be used. While adrenergic drug interactions with linezolid are less common in clinical practice, monitoring for signs of hypertension remains important.

Linezolid is associated with serotonin syndrome in a patient receiving amitriptyline, and fentanyl: a case report and review of the literature

We report a unique case of an adverse interaction between the oxazolidinone antibiotic linezolid, the tricyclic antidepressant amitriptyline and the opioid analgesic fentanyl in a 68-year-old woman with advanced ischemic peripheral arterial disease and sepsis, under empirical antibiotic treatment. We also summarize the current relevant literature as identified via PubMed, EMBASE, and PsycINFO as well as reference sections of selected articles.

Clinical relevance of linezolid-associated serotonin toxicity

OBJECTIVE

To evaluate and review the literature surrounding serotonin toxicity in patients receiving linezolid and determine the clinical relevance of this reaction.

DATA SOURCES

Literature was accessed via MEDLINE/PubMed and Google Scholar (both through February 2013) using the search terms linezolid, serotonin syndrome, serotonin toxicity, and adverse reaction.

STUDY SELECTION AND DATA EXTRACTION

Relevant case reports, retrospective studies, surveys, and review articles were included. Bibliographies of all relevant articles were reviewed for additional sources.

DATA SYNTHESIS

Linezolid exhibits mild, nonselective inhibition of monoamine oxidase and has been associated with serotonin toxicity when used in combination with other serotonergic agents. Based on published reports, the incidence of linezolid-associated serotonin toxicity is between 0.54% and 18.2%. Our review identified 32 documented cases, including 3 fatalities. Most cases occurred in patients concurrently receiving selective serotonin reuptake inhibitors. Receipt of multiple agents with serotonergic activity seems to increase the risk of serotonin toxicity. Both onset and resolution of symptoms varied from hours to days.

CONCLUSIONS

Current Food and Drug Administration recommendations to avoid the use of linezolid in patients receiving select serotonergic agents highlight the need to carefully balance the risk/benefit ratio in this situation. Although linezolid has been available for 12 years, reports of serotonin toxicity with this agent are uncommon. While clinicians should be aware of this potentially severe interaction and closely monitor patients who are receiving linezolid in combination with serotonergic agents, our findings show that linezolid is not contraindicated in this situation.

An evidence-based review of linezolid for the treatment of methicillin-resistant Staphylococcus aureus (MRSA): place in therapy

Methicillin-resistant Staphylococcus aureus (MRSA), including community-associated and hospital-associated strains, is a major cause of human morbidity and mortality. Treatment options have become limited due to the emergence of MRSA strains with decreased sensitivity to vancomycin, which has long been the first-line therapy for serious infections. This has prompted the search for novel antibiotics that are efficacious against MRSA. Linezolid, an oxazolidinone class of antibiotic, was approved by the Food and Drug Administration in 2000 for treatment of MRSA infections. Since then, there have been a multitude of clinical trials and research studies evaluating the effectiveness of linezolid against serious infections, including pneumonia (both community- and hospital-acquired), skin and soft-tissue infections such as diabetic foot ulcers, endocarditis, osteomyelitis, prosthetic devices, and others. The primary aim of this review is to provide an up-to-date evaluation of the clinical evidence for using linezolid to treat MRSA infections, with a focus on recently published studies, including those on nosocomial pneumonia. Other objectives are to analyze the cost-effectiveness of linezolid compared to other agents, and to review the pharmokinetics and pharmacodynamics of linezolid, emphasizing the most current concepts.