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Featured researches published by Stephen K. Field.


Annals of Internal Medicine | 2007

Tiotropium in Combination with Placebo, Salmeterol, or Fluticasone–Salmeterol for Treatment of Chronic Obstructive Pulmonary Disease: A Randomized Trial

Shawn D. Aaron; Katherine L. Vandemheen; Dean Fergusson; François Maltais; Jean Bourbeau; Roger S. Goldstein; Meyer Balter; Denis E. O'Donnell; Andrew McIvor; Sat Sharma; Graham Bishop; John Anthony; Robert Cowie; Stephen K. Field; Andrew Hirsch; Paul Hernandez; Robert N. Rivington; Jeremy Road; Victor Hoffstein; Richard V. Hodder; Darcy Marciniuk; David G. McCormack; George A Fox; Gerard Cox; Henry B. Prins; Dominique Bleskie; Steve Doucette; Irvin Mayers; Kenneth R. Chapman; Noe Zamel

Context Physicians use multiple medications to treat chronic obstructive pulmonary disease (COPD). Contribution In this multicenter trial, 449 adults with moderate or severe COPD were randomly assigned to receive tiotropium and placebo, tiotropium and salmeterol, or tiotropium and fluticasonesalmeterol for 1 year. About 63%, 65%, and 60% of patients, respectively, had exacerbations. The third group, but not the second group, had better lung function and fewer hospitalizations than the first group. Caution Many patients discontinued assigned medications. Implications Adding fluticasonesalmeterol to tiotropium may improve lung function and decrease hospitalizations, but it does not affect reduce exacerbations in patients with moderate or severe COPD. The Editors Most patients with moderate or severe chronic obstructive pulmonary disease (COPD) experience chronic progressive dyspnea that is not alleviated by short-acting bronchodilators. It is therefore not surprising that many patients are treated with multiple inhaled medications to optimize their lung function and minimize symptoms (1). Published guidelines on COPD state that the goals of pharmacologic therapy should be to control symptoms, improve health status, and reduce the frequency of COPD exacerbations (2, 3), and many published guidelines advocate combining different classes of long-acting bronchodilators or inhaled steroids to achieve these goals (2, 3). In the past several years, several studies have shown that treatment of COPD with the long-acting anticholinergic tiotropium (47); the long-acting 2-agonist salmeterol (810); or products that combine inhaled steroids and long-acting 2-agonists, such as fluticasonesalmeterol or budesonideformoterol (1114), improve dyspnea and quality of life and decrease exacerbation rates compared with placebo. However, no studies have assessed whether therapy with a combination of these products provides greater clinical benefit than does therapy with these agents used alone. 2-Agonists and anticholinergics work by different mechanisms to cause bronchodilation (15), and inhaled corticosteroids may have an anti-inflammatory effect in COPD (16). Thus, it makes theoretical and intuitive sense that combining these therapies might be more beneficial than therapy with 1 agent alone. However, safety concerns, such as side effects associated with long-term use of long-acting 2-agonists and inhaled corticosteroids, and economic issues related to the additional costs of these medications may argue against routine use of inhaled medication polypharmacy without evidence of efficacy. We therefore conducted a randomized, double-blind, placebo-controlled clinical trial to determine whether combining tiotropium with salmeterol or fluticasonesalmeterol produces greater improvements in clinical outcomes for adults with moderate or severe COPD compared with tiotropium therapy alone. Methods Design We designed a parallel-group, 3-group, randomized, double-blind, placebo-controlled trial in patients with moderate or severe COPD that was conducted from October 2003 to January 2006. The study protocol has been published elsewhere (17). The research ethics boards of all participating centers approved the study, and all trial participants provided written informed consent. Setting and Participants We enrolled patients with diagnosed moderate or severe COPD from 27 Canadian medical centers. Twenty centers were academic hospitalbased pulmonary clinics, 5 were community-based pulmonary clinics, and 2 were community-based primary care clinics. Eligible patients had to have had at least 1 exacerbation of COPD that required treatment with systemic steroids or antibiotics within the 12 months before randomization. Additional inclusion criteria were age older than 35 years; a history of 10 pack-years or more of cigarette smoking; and documented chronic airflow obstruction, with an FEV1FVC ratio less than 0.70 and a postbronchodilator FEV1 less than 65% of the predicted value. We excluded patients with a history of physician-diagnosed asthma before 40 years of age; those with a history of physician-diagnosed chronic congestive heart failure with known persistent severe left ventricular dysfunction; those receiving oral prednisone; those with a known hypersensitivity or intolerance to tiotropium, salmeterol, or fluticasonesalmeterol; those with a history of severe glaucoma or severe urinary tract obstruction, previous lung transplantation or lung volume reduction surgery, or diffuse bilateral bronchiectasis; and those who were pregnant or were breastfeeding. Persons with a recent COPD exacerbation requiring oral or intravenous antibiotics or steroids were required to wait until treatment with these agents had been discontinued for 28 days before entering the study. Randomization and Interventions We randomly assigned patients to 1 of 3 treatment groups for 52 weeks: tiotropium (Spiriva [Boehringer Ingelheim Pharma, Ingelheim, Germany]), 18 g once daily, plus placebo inhaler, 2 puffs twice daily; tiotropium, 18 g once daily, plus salmeterol (Serevent [GlaxoSmithKline, Research Triangle Park, North Carolina]), 25 g/puff, 2 puffs twice daily; or tiotropium, 18 g once daily, plus fluticasonesalmeterol (Advair [GlaxoSmithKline]), 250/25 g/puff, 2 puffs twice daily. Randomization was done through central allocation of a randomization schedule that was prepared from a computer-generated random listing of the 3 treatment allocations, blocked in variable blocks of 9 or 12 and stratified by site. Neither research staff nor patients were aware of the treatment assignment before or after randomization. All study patients were provided with inhaled albuterol and were instructed to use it when necessary to relieve symptoms. Any treatment with inhaled corticosteroids, long-acting 2-agonists, and anticholinergics that the patient may have been using before entry was discontinued on entry into the study. Therapy with other respiratory medications, such as oxygen, antileukotrienes, and methylxanthines, was continued in all patient groups. Tiotropium was administered by using a Handihaler device (Boehringer Ingelheim). Study drugs were administered through a pressurized metered-dose inhaler using a spacer device (Aerochamber Plus, Trudell Medical, London, Ontario, Canada), and patients were taught the correct inhalation technique to ensure adequate drug delivery. The metered-dose inhalers containing placebo, salmeterol, and fluticasonesalmeterol were identical in taste and appearance, and they were enclosed in identical tamper-proof blinding devices. The medication canisters within the blinding devices were stripped of any identifying labeling. Adherence to therapy was assessed by weighing the returned inhaler canisters. Measurements and Outcomes The primary outcome was the proportion of patients in each treatment group who experienced a COPD exacerbation within 52 weeks of randomization. Respiratory exacerbations were defined, according to the 2000 Aspen Lung Conference Consensus definition, as a sustained worsening of the patients respiratory condition, from the stable state and beyond normal day-to-day variations, necessitating a change in regular medication in a patient with underlying COPD (18). An acute change in regular COPD medications was defined as physician-directed, short-term use of oral or intravenous steroids, oral or intravenous antibiotics, or both therapies. Secondary outcomes were the mean number of COPD exacerbations per patient-year; the total number of exacerbations that resulted in urgent visits to a health care provider or emergency department; the number of hospitalizations for COPD; the total number of hospitalizations for all causes; and changes in health-related quality of life, dyspnea, and lung function. Health-related quality of life was assessed by using the St. Georges Respiratory Questionnaire (19), dyspnea was assessed by using the Transitional Dyspnea Index (20) and the dyspnea domain of the Chronic Respiratory Disease Questionnaire (21), and lung function was assessed by measuring the FEV1 according to established criteria of the American Thoracic Society. Follow-up Procedures Patients were monitored for exacerbations by monthly telephone calls. Exacerbations and all secondary outcomes were also assessed through patient visits at baseline and at 4, 20, 36, and 52 weeks after randomization. For every suspected exacerbation, we contacted both the patient and the patients treating physician to ensure that the medical encounter had been prompted by acute respiratory symptoms and a full report, including physician, emergency department, and hospital records that described the circumstances of each suspected exacerbation, was prepared. The assembled data from the visit for the suspected exacerbation were presented to a blinded adjudication committee for review, and the committee confirmed whether the encounter met the study definition of COPD exacerbation. For the purposes of the trial, we considered that a patient had experienced a new COPD exacerbation if he or she had not been receiving oral steroids and antibiotics for at least 14 days after the previous exacerbation. Patients were followed for the full 52-week duration of the trial, and primary and secondary outcomes were recorded throughout the 1-year period regardless of whether patients had experienced an exacerbation or discontinued treatment with study medications. We did not break the study blinding for patients who prematurely discontinued treatment with study medications. Adverse events were captured by the research coordinators through monthly patient telephone interviews and at scheduled patient visits by using checklists of potential side effects. Physicians rated events as expected or unexpected, and they were asked to rate event severity and attribute causality of adverse events to the study drugs. Statistical Analysis We designed the study to detect an 18% absolute d


Canadian Medical Association Journal | 2008

Overdiagnosis of asthma in obese and nonobese adults

Shawn D. Aaron; Katherine L. Vandemheen; Louis-Philippe Boulet; R. Andrew McIvor; J. Mark FitzGerald; Paul Hernandez; Catherine Lemière; Sat Sharma; Stephen K. Field; Gonzalo G. Alvarez; Robert E. Dales; Steve Doucette; Dean Fergusson

Background: It is unclear whether asthma is overdiagnosed in developed countries, particularly among obese individuals, who may be more likely than nonobese people to experience dyspnea. Methods: We conducted a longitudinal study involving nonobese (body mass index 20–25) and obese (body mass index ≥ 30) individuals with asthma that had been diagnosed by a physician. Participants were recruited from 8 Canadian cities by means of random-digit dialing. A diagnosis of current asthma was excluded in those who did not have evidence of acute worsening of asthma symptoms, reversible airflow obstruction or bronchial hyperresponsiveness, despite being weaned off asthma medications. We stopped asthma medications in those in whom a diagnosis of asthma was excluded and assessed their clinical outcomes over 6 months. Results: Of 540 individuals with physician-diagnosed asthma who participated in the study, 496 (242 obese and 254 nonobese) could be conclusively assessed for a diagnosis of asthma. Asthma was ultimately excluded in 31.8% (95% confidence interval [CI] 26.3%–37.9%) in the obese group and in 28.7% (95% CI 23.5%–34.6%) in the nonobese group. Overdiagnosis of asthma was no more likely to occur among obese individuals than among nonobese individuals (p = 0.46). Of those in whom asthma was excluded, 65.5% did not need to take asthma medication or seek health care services because of asthma symptoms during a 6-month follow-up period. Interpretation: About one-third of obese and nonobese individuals with physician-diagnosed asthma did not have asthma when objectively assessed. This finding suggests that, in developed countries such as Canada, asthma is overdiagnosed.


Chest | 2009

A Randomized Controlled Trial of Standard vs Endobronchial Ultrasonography-Guided Transbronchial Needle Aspiration in Patients With Suspected Sarcoidosis

Alain Tremblay; David R. Stather; Paul MacEachern; Moosa Khalil; Stephen K. Field

BACKGROUND Endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) of mediastinal lymph nodes has been found to be more accurate than standard TBNA in the setting of malignancy. In patients with suspected sarcoidosis, the smaller ultrasound needle may yield inadequate material to make a histologic diagnosis of granulomatous inflammation. The aim of this study was to compare the diagnostic yield of EBUS-guided TBNA to TBNA performed with a standard 19-gauge needle in patients with mediastinal adenopathy and a clinical suspicion of sarcoidosis. METHODS A randomized controlled trial was performed in a university medical center, enrolling 50 patients (of 61 screened, 2 declined, and 9 did not meet entry criteria) with hilar and/or mediastinal adenopathy and a clinical suspicion of sarcoidosis. Twenty-four patients were randomized to undergo EBUS-guided TBNA and 26 to undergo TBNA using a standard 19-gauge needle. RESULTS The primary outcome measure of diagnostic yield was 53.8% vs 83.3% in favor of the EBUS-guided TBNA group, an absolute increase of 29.5% (p < 0.05; 95% confidence interval [CI], 8.6 to 55.4%). After blinded research pathology review, diagnostic yield was 73.1% vs 95.8%, in favor of the EBUS-guided TBNA group, an absolute increase of 22.7% (p = 0.05; 95% CI, 1.9 to 42.2%). Sensitivity and specificity were 60.9% and 100%, respectively, in the standard TBNA group, and 83.3% and 100%, respectively, in the EBUS-guided TBNA group (absolute increase in sensitivity, 22.5%; p = 0.085; 95% CI, 3.2 to 44.9%). CONCLUSIONS The diagnostic yield of EBUS-guided TBNA is superior to TBNA using a standard 19-gauge needle for sampling of mediastinal lymph nodes in patients with a clinical suspicion of sarcoidosis. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00373555.


JAMA | 2017

Reevaluation of Diagnosis in Adults With Physician-Diagnosed Asthma.

Shawn D. Aaron; Katherine L. Vandemheen; J. Mark FitzGerald; Martha Ainslie; Samir Gupta; Catherine Lemière; Stephen K. Field; R. Andrew McIvor; Paul Hernandez; Irvin Mayers; Sunita Mulpuru; Gonzalo G. Alvarez; Smita Pakhale; Ranjeeta Mallick; Louis-Philippe Boulet

Importance Although asthma is a chronic disease, the expected rate of spontaneous remissions of adult asthma and the stability of diagnosis are unknown. Objective To determine whether a diagnosis of current asthma could be ruled out and asthma medications safely stopped in randomly selected adults with physician-diagnosed asthma. Design, Setting, and Participants A prospective, multicenter cohort study was conducted in 10 Canadian cities from January 2012 to February 2016. Random digit dialing was used to recruit adult participants who reported a history of physician-diagnosed asthma established within the past 5 years. Participants using long-term oral steroids and participants unable to be tested using spirometry were excluded. Information from the diagnosing physician was obtained to determine how the diagnosis of asthma was originally made in the community. Of 1026 potential participants who fulfilled eligibility criteria during telephone screening, 701 (68.3%) agreed to enter into the study. All participants were assessed with home peak flow and symptom monitoring, spirometry, and serial bronchial challenge tests, and those participants using daily asthma medications had their medications gradually tapered off over 4 study visits. Participants in whom a diagnosis of current asthma was ultimately ruled out were followed up clinically with repeated bronchial challenge tests over 1 year. Exposure Physician-diagnosed asthma established within the past 5 years. Main Outcomes and Measures The primary outcome was the proportion of participants in whom a diagnosis of current asthma was ruled out, defined as participants who exhibited no evidence of acute worsening of asthma symptoms, reversible airflow obstruction, or bronchial hyperresponsiveness after having all asthma medications tapered off and after a study pulmonologist established an alternative diagnosis. Secondary outcomes included the proportion with asthma ruled out after 12 months and the proportion who underwent an appropriate initial diagnostic workup for asthma in the community. Results Of 701 participants (mean [SD] age, 51 [16] years; 467 women [67%]), 613 completed the study and could be conclusively evaluated for a diagnosis of current asthma. Current asthma was ruled out in 203 of 613 study participants (33.1%; 95% CI, 29.4%-36.8%). Twelve participants (2.0%) were found to have serious cardiorespiratory conditions that had been previously misdiagnosed as asthma in the community. After an additional 12 months of follow-up, 181 participants (29.5%; 95% CI, 25.9%-33.1%) continued to exhibit no clinical or laboratory evidence of asthma. Participants in whom current asthma was ruled out, compared with those in whom it was confirmed, were less likely to have undergone testing for airflow limitation in the community at the time of initial diagnosis (43.8% vs 55.6%, respectively; absolute difference, 11.8%; 95% CI, 2.1%-21.5%). Conclusions and Relevance Among adults with physician-diagnosed asthma, a current diagnosis of asthma could not be established in 33.1% who were not using daily asthma medications or had medications weaned. In patients such as these, reassessing the asthma diagnosis may be warranted.


Chest | 2010

A Comparison of Obese and Nonobese People With Asthma Exploring an Asthma-Obesity Interaction

Smita Pakhale; Steve Doucette; Katherine L. Vandemheen; Louise-Philippe Boulet; R. Andrew McIvor; J. Mark FitzGerald; Paul Hernandez; Catherine Lemière; Sat Sharma; Stephen K. Field; Gonzalo G. Alvarez; Robert E. Dales; Shawn D. Aaron

OBJECTIVE The objectives of our study were to compare patient characteristics and severity of disease in obese and normal-weight-confirmed people with asthma and to explore reasons for misdiagnosis of asthma, including potential interactions with obesity. METHODS We randomly selected patients with physician-diagnosed asthma from eight Canadian cities. Asthma diagnosis was confirmed via a sequential lung function testing algorithm. Logistic analysis was conducted to compare obese and normal-weight-confirmed people with asthma and to assess characteristics associated with misdiagnosis of asthma. Interaction with obesity was investigated. RESULTS Complete assessments were obtained on 496 subjects who reported physician-diagnosed asthma (242 obese and 254 normal-weight subjects); 346 had asthma confirmed with sequential lung testing, and in 150 subjects a diagnosis of asthma was ruled out. Obese subjects with asthma were significantly more likely to be men, have a history of hypertension and gastroesophageal reflux disease, and have a lower FEV(1) compared with normal-weight subjects with asthma. Older subjects, men, and subjects with higher FEV(1) were more likely to have received misdiagnoses of asthma. Obesity was not an independent predictor of misdiagnosis, however there was an interaction between obesity and urgent visits for respiratory symptoms. The odds ratio for receiving a misdiagnosis of asthma for obese individuals as compared with normal-weight individuals was 4.08 (95% CI, 1.23-13.5) for those with urgent visits in the past 12 months. CONCLUSIONS Obese people with asthma have lower lung function and more comorbidities compared with normal-weight people with asthma. Obese individuals who make urgent visits for respiratory symptoms are more likely to receive a misdiagnosis of asthma.


Journal of Asthma | 2001

Predicting Emergency Department Utilization in Adults with Asthma: A Cohort Study

Robert Cowie; Margot F. Underwood; Shirley G. Revitt; Stephen K. Field

A consecutive sample of 378 adults with asthma were assessed at a university asthma program and then interviewed 1 year later regarding their need for emergency department (E.D.) asthma treatment. The purpose of this prospective cohort study was to determine whether any of their initial features could predict their subsequent need for E.D. asthma treatment. At one year, a total of 73 of the subjects had attended emergency departments for asthma. On entry, the 73 subjects had demonstrated more self-reported lifestyle restriction from asthma and more hospital admissions E.D. visits for asthma as well as poorer asthma control or than had the 305 subjects who had not required E.D. asthma treatment since entry to the cohort. This study suggests that special attention should be paid to subjects with asthma that interferes with their lifestyle and to those who have needed hospital admission for asthma.


Thorax | 2013

TNFα antagonists for acute exacerbations of COPD: a randomised double-blind controlled trial

Shawn D. Aaron; Katherine L. Vandemheen; François Maltais; Stephen K. Field; Don D Sin; Jean Bourbeau; Darcy Marciniuk; J Mark FitzGerald; Parameswaran Nair; Ranjeeta Mallick

Background The purpose of this randomised double-blind double-dummy placebo-controlled trial was to investigate whether etanercept, a tumour necrosis factor α (TNFα) antagonist, would provide more effective anti-inflammatory treatment for acute exacerbations of chronic obstructive pulmonary disease (COPD) than prednisone. Methods We enrolled 81 patients with acute exacerbations of COPD and randomly assigned them to treatment with either 40 mg oral prednisone given daily for 10 days or to 50 mg etanercept given subcutaneously at randomisation and 1 week later. Both groups received levofloxacin for 10 days plus inhaled bronchodilators. The primary endpoint was the change in the patients forced expiratory volume in 1 s (FEV1) 14 days after randomisation. Secondary endpoints included 90-day treatment failure rates and dyspnoea and quality of life. Results At 14 days the mean±SE change in FEV1 from baseline was 20.1±5.0% and 15.2±5.7% for the prednisone and etanercept groups, respectively. The mean between-treatment difference was 4.9% (95% CI −10.3% to 20.2%), p=0.52. Rates of treatment failure at 90 days were similar in the prednisone and etanercept groups (32% vs 40%, p=0.44), as were measures of dyspnoea and quality of life. Subgroup analysis revealed that patients with serum eosinophils >2% at exacerbation tended to experience fewer treatment failures if treated with prednisone compared with etanercept (22% vs 50%, p=0.08). Conclusions Etanercept was not more effective than prednisone for treatment of acute exacerbations of COPD. Efficacy of prednisone was most apparent in patients who presented with serum eosinophils >2%. Clinical Trials gov number NCT 00789997.


Chest | 2015

Tools for Assessing Outcomes in Studies of Chronic Cough: CHEST Guideline and Expert Panel Report

Louis-Philippe Boulet; Remy R Coeytaux; Douglas C McCrory; Cynthia T. French; Anne B. Chang; Surinder S. Birring; Jaclyn A. Smith; Rebecca L. Diekemper; Bruce K. Rubin; Richard S. Irwin; Todd M. Adams; Kenneth W. Altman; Alan F. Barker; Fiona Blackhall; Donald C. Bolser; Sidney S. Braman; Christopher E. Brightling; Priscilla Callahan-Lyon; Anne Bernadette Chang; Remy Coeytaux; Terrie Cowley; Paul W. Davenport; Satoru Ebihara; Ali A. El Solh; Patricio Escalante; Anthony Feinstein; Stephen K. Field; Dina Fisher; Peter G. Gibson; Philip Gold

BACKGROUND Since the publication of the 2006 American College of Chest Physicians (CHEST) cough guidelines, a variety of tools has been developed or further refined for assessing cough. The purpose of the present committee was to evaluate instruments used by investigators performing clinical research on chronic cough. The specific aims were to (1) assess the performance of tools designed to measure cough frequency, severity, and impact in adults, adolescents, and children with chronic cough and (2) make recommendations or suggestions related to these findings. METHODS By following the CHEST methodologic guidelines, the CHEST Expert Cough Panel based its recommendations and suggestions on a recently published comparative effectiveness review commissioned by the US Agency for Healthcare Research and Quality, a corresponding summary published in CHEST, and an updated systematic review through November 2013. Recommendations or suggestions based on these data were discussed, graded, and voted on during a meeting of the Expert Cough Panel. RESULTS We recommend for adults, adolescents (≥ 14 years of age), and children complaining of chronic cough that validated and reliable health-related quality-of-life (QoL) questionnaires be used as the measurement of choice to assess the impact of cough, such as the Leicester Cough Questionnaire and the Cough-Specific Quality-of-Life Questionnaire in adult and adolescent patients and the Parent Cough-Specific Quality of Life Questionnaire in children. We recommend acoustic cough counting to assess cough frequency but not cough severity. Limited data exist regarding the performance of visual analog scales, numeric rating scales, and tussigenic challenges. CONCLUSIONS Validated and reliable cough-specific health-related QoL questionnaires are recommended as the measurement of choice to assess the impact of cough on patients. How they compare is yet to be determined. When used, the reporting of cough severity by visual analog or numeric rating scales should be standardized. Previously validated QoL questionnaires or other cough assessments should not be modified unless the new version has been shown to be reliable and valid. Finally, in research settings, tussigenic challenges play a role in understanding mechanisms of cough.


Chest | 2014

Overview of the Management of Cough: CHEST Guideline and Expert Panel Report

Richard S. Irwin; Cynthia T. French; Sandra Zelman Lewis; Rebecca L. Diekemper; Philip Gold; Todd M. Adams; Kenneth W. Altman; Alan F. Barker; Surinder S. Birring; Donald C. Bolser; Louis Philippe Boulet; Sidney S. Braman; Christopher E. Brightling; Priscilla Callahan-Lyon; Brendan J. Canning; Anne B. Chang; Remy R Coeytaux; Terrie Cowley; Paul W. Davenport; Satoru Ebihara; Ali A. El Solh; Patricio Escalante; Stephen K. Field; Dina Fisher; Peter G. Gibson; Michael K. Gould; Susan M. Harding; Anthony Harnden; Adam T. Hill; Peter J. Kahrilas

This overview will demonstrate that cough is a common and potentially expensive health-care problem. Improvement in the quality of care of those with cough has been the focus of study for a variety of disciplines in medicine. The purpose of the Cough Guideline and Expert Panel is to synthesize current knowledge in a form that will aid clinical decision-making for the diagnosis and management of cough across disciplines and also identify gaps in knowledge and treatment options.


Therapeutic Advances in Chronic Disease | 2015

Bedaquiline for the treatment of multidrug-resistant tuberculosis: great promise or disappointment?

Stephen K. Field

Acquired drug resistance by Mycobacterium tuberculosis (MTB) may result in treatment failure and death. Bedaquiline was recently approved for the treatment of multidrug-resistant tuberculosis (MDR-TB). This report examines the available data on this novel drug for the treatment of MDR-TB. PubMed searches, last updated 18 February 2015, using the terms bedaquiline, TMC 207 and R207910 identified pertinent English citations. Citation reference lists were reviewed to identify other relevant reports. Pertinent MDR-TB treatment reports on the US Food and Drug Administration, Centers for Disease Control and Prevention (CDC), World Health Organization (WHO) and Cochrane websites were also evaluated. Bedaquiline is an adenosine triphosphate (ATP) synthase inhibitor specific for MTB and some nontuberculous mycobacteria. The early bactericidal activity (EBA) of bedaquiline is delayed until ATP stores are depleted but subsequently it is similar to the EBA of isoniazid and rifampin. Bedaquiline demonstrated excellent minimum inhibitory concentrations (MICs) against both drug-sensitive and MDR-TB. Adding it to the WHO-recommended MDR-TB regimen reduced the time for sputum culture conversion in pulmonary MDR-TB. Rifampin, other cytochrome oxidase 3A4 inducers or inhibitors alter its metabolism. Adverse effects are common with MDR-TB treatment regimens with or without bedaquiline. Nausea is more common with bedaquiline and it increases the QTcF interval. It is not recommended for children, pregnant or lactating women. More patients died in the bedaquiline-treatment arms despite better microbiological outcomes in two recent trials. The WHO and CDC published interim guidelines that recommend restricting its use to patients with MDR-TB or more complex drug resistance who cannot otherwise be treated with a minimum of three effective drugs. It should never be added to a regimen as a single drug nor should it be added to a failing regimen to prevent the emergence of bedaquiline-resistant strains.

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Kenneth W. Altman

Icahn School of Medicine at Mount Sinai

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Anne B. Chang

Queensland University of Technology

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Richard S. Irwin

University of Massachusetts Medical School

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