Adverse Events Associated With the Treatment of Multidrug-Resistant Tuberculosis: A Systematic Review and Meta-analysis

Putting in harm to cure: Drug related adverse events do not affect outcome of patients receiving treatment for multidrug-resistant Tuberculosis. Experience from a tertiary hospital in Italy

Rationale

Treatment of multi-drug resistant Tuberculosis (MDR-TB) is challenging because it mostly relies on drugs with lower efficacy and greater toxicity than those used for drug-susceptible TB.

Objectives

Aim of the study was to describe the frequency and type of adverse drug reactions in a cohort of MDR-TB patients and their potential impact on treatment outcome.

Methods

We conducted a retrospective study in a cohort of MDR-TB patients enrolled at a tertiary referral hospital in Italy from January 2008 to December 2016. The records of patients were reviewed for epidemiological, clinical, microbiological and adverse drug reactions data.

Results

Seventy-four MDR-TB patients (mean age 32 years, 58.1% males, 2 XDR, 12 pre-XDR TB) were extracted from the Institute data base and included in the retrospective study cohort in the evaluation period (January 2008—December 2016). Median length of treatment duration was 20 months (IQR 14–24). Treatment outcome was successful in 57 patients (77%; 51 cured, 6 treatment completed); one patient died and one failed (2.7% overall); 15 patients were lost to follow-up (20.3%). Sixty-six (89.2%) presented adverse drug reactions during the whole treatment period. Total number of adverse drug reactions registered was 409. Three hundred forty-six (84.6%) were classified as adverse events (AEs) and 63 (15.4%) were serious AEs (SAEs). One third of the total adverse drug reactions (134/409; 32.8%) was of gastrointestinal origin, followed by 47/409 (11.5%) ototoxic drug reactions, thirty-five (8.6%) regarded central nervous system and 33 (8.1%) affected the liver. All 63 SAEs required treatment suspension with 61 SAEs out of 63 (96.8%) occurring during the first six months of treatment. Factors associated with unsuccessful treatment outcome were smoking (p = 0.039), alcohol abuse (p = 0.005) and homeless condition (p = 0.044). Neither the number of antitubercular drugs used in different combinations nor the number of AEs showed significant impact on outcome. Patients who completed the treatment experienced a greater number of AEs and SAEs (p < 0.001) if compared to lost to follow-up patients.

Conclusions

Our data demonstrate that, despite the high frequency of adverse drug reactions and long term therapy, the clinical management of MDR-TB patients in a referral center could reach successful treatment according to WHO target, by implementing active and systematic clinical and laboratory assessment to detect, report and manage suspected and confirmed adverse drug reactions.

Safety, efficacy, and pharmacokinetics of bedaquiline in Japanese patients with pulmonary multidrug-resistant tuberculosis: An interim analysis of an open-label, phase 2 study

BACKGROUND

Bedaquiline, a diarylquinoline with a novel mode of action that specifically inhibits mycobacterial adenosine 5׳-triphosphate (ATP) synthase, has been approved in over 50 countries including the USA and EU for the treatment of pulmonary multidrug-resistant tuberculosis (pMDR-TB) in adults.

METHODS

This study was conducted to evaluate the safety, efficacy, and pharmacokinetics of bedaquiline in adult Japanese patients with pMDR-TB. In this study, patients received bedaquiline for 24 weeks or more (maximum 48 weeks) with an individualized background regimen (BR). Efficacy was assessed as the time to sputum culture conversion after the initiation of bedaquiline treatment.

RESULTS

Treatment-emergent adverse events (TEAEs) were reported in 5/6 patients (83.3%) during the investigational phase (bedaquiline treatment + 1 week). The TEAEs observed in >1 patient were hepatic function abnormal (4/6), hypoaesthesia (3/6), nasopharyngitis, acne, and nausea (2/6 each). The TEAEs leading to treatment discontinuation of bedaquiline were none. The time to sputum culture conversion was 14-15 days. Plasma bedaquiline C_max was achieved within 4-6 h of bedaquiline administration and AUC_24h ranged from 50,637 to 107,300 ng*h/mL (5 patients) at week 2 and were 58,513 and 77,148 ng *h/mL (2 patients) at week 24.

CONCLUSIONS

No new safety signals in patients, including those receiving bedaquiline with BR beyond 24 weeks, and the faster culture conversion time indicate that the administration of bedaquiline as part of a multi-drug regimen for at least 24 weeks is a suitable treatment for adult Japanese patients with pMDR-TB.

Delamanid, linezolid, levofloxacin, and pyrazinamide for the treatment of patients with fluoroquinolone-sensitive multidrug-resistant tuberculosis (Treatment Shortening of MDR-TB Using Existing and New Drugs, MDR-END): study protocol for a phase II/III, multicenter, randomized, open-label clinical trial

Background

Treatment success rates of multidrug-resistant tuberculosis (MDR-TB) remain unsatisfactory, and long-term use of second-line anti-TB drugs is accompanied by the frequent occurrence of adverse events, low treatment compliance, and high costs. The development of new efficient regimens with shorter treatment durations for MDR-TB will solve these issues and improve treatment outcomes.

Methods

This study is a phase II/III, multicenter, randomized, open-label clinical trial of non-inferiority design comparing a new regimen to the World Health Organization-endorsed conventional regimen for fluoroquinolone-sensitive MDR-TB. The control arm uses a conventional treatment regimen with second-line drugs including injectables for 20–24 months. The investigational arm uses a new shorter regimen including delamanid, linezolid, levofloxacin, and pyrazinamide for 9 or 12 months depending on time to sputum culture conversion. The primary outcome is the treatment success rate at 24 months after treatment initiation. Secondary outcomes include time to sputum culture conversion on liquid and solid media, proportions of sputum culture conversion on liquid media after 2 and 6 months of treatment, treatment success rate according to pyrazinamide resistance, and occurrence of adverse events grade 3 and above as evaluated by the Common Terminology Criteria for Adverse Events. Based on an α = 0.025 level of significance (one-sided test), a power of 80%, and a < 10% difference in treatment success rate between the control and investigational arms (80% vs. 70%) when the anticipated actual success rate in the treatment group is assumed to be 90%, the number of participants needed per arm to show non-inferiority of the investigational regimen was calculated as 48. Additionally, assuming the proportion of fluoroquinolone-susceptible MDR-TB among participants as 50%, and 5% loss to follow-up, the number of participants is calculated as N/( 0.50 × 0.95), resulting in 102 persons per group (204 in total).

Discussion

This trial will reveal the effectiveness and safety of a new shorter regimen comprising four oral drugs, including delamanid, linezolid, levofloxacin, and pyrazinamide, for the treatment of fluoroquinolone-sensitive MDR-TB. Results from this trial will provide evidence for adopting a shorter and more convenient treatment regimen for MDR-TB.

Trial registration

ClincalTrials.gov, NCT02619994. Registered on 2 December 2015.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3053-1) contains supplementary material, which is available to authorized users.

A survey of the tuberculosis physician workforce in the country of Georgia

SETTING

A well-trained and sufficient tuberculosis (TB) workforce is essential for disease control, especially in an era of newly implemented diagnostics and medications. However, there are few reports on the status of the TB workforce in many endemic countries.

OBJECTIVE

To evaluate the demographics, salary, career satisfaction, and attitudes towards the field of TB among the physician TB workforce in the country of Georgia.

DESIGN

A cross-sectional study of physicians in the current Georgian National TB Programme (NTP) using an anonymous 31-item questionnaire.

RESULTS

Among 184 NTP physicians countrywide, 142 (77%) were contacted and 138 (75%) completed questionnaires. The median age was 56 years (interquartile range 50-64); most (81%) were female. The monthly salary from TB work was USD205 for 50% of respondents. Nearly half (47%) received an additional salary from another source. Many physicians (65%) indicated that they were satisfied with their work, but over half (55%) were unsatisfied with reimbursement. While most physicians (78%) were concerned about the lack of interest in TB, only 36% would recommend a career in TB care.

CONCLUSION

While the current TB workforce in Georgia finds their work fulfilling, an ageing workforce, low salaries and perceived lack of interest in the field are a matter of concern for future TB control.

Adverse drug reactions during drug-resistant TB treatment in high HIV prevalence settings: a systematic review and meta-analysis

Objectives

To estimate the prevalence of adverse drug reactions or events (ADR) during drug-resistant TB (DR-TB) treatment in the context of settings with high HIV prevalence (at least 20% of patients).

Methods

We conducted a systematic review and meta-analysis of articles in PubMed and Scopus. Pooled proportions of patients experiencing adverse events and relative risk with 95% CI were calculated.

Results

The search yielded 24 studies, all observational cohorts. Ten reported on the number of patients experiencing ADR and were included in the meta-analysis representing 2776 study participants of whom 1943 were known to be HIV infected (70.0%). An average of 83% (95% CI: 82%-84%) of patients experienced one or more ADR. Among the seven articles ( n  =   664 study participants) with information on occurrence of severe ADR, 24% (95% CI: 21%-27%) of patients experienced at least one severe ADR during drug-resistant TB treatment. Sixteen of the 24 studies analysed the relative risk of ADR by HIV infection, nine of which found no statistically significant association between HIV infection and occurrence of drug-related ADR. There was insufficient information to disaggregate risk by concomitant treatment with HIV antiretrovirals or by immunosuppression (CD4 count).

Conclusions

No randomized clinical trials were found for WHO-recommended treatment of drug-resistant TB treatment where at least 20% of the cohort was coinfected with HIV. Nearly all patients (83%) experience ADR during DR-TB treatment. While no significant association between ADR and HIV coinfection was found, further research is needed to determine whether concomitant antiretrovirals or immunosuppression increases the risks for HIV-infected patients.

Multidrug-resistant tuberculosis treatment adherence in migrants: a systematic review and meta-analysis

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) is a growing concern in meeting global targets for TB control. In high-income low-TB-incidence countries, a disproportionate number of MDR-TB cases occur in migrant (foreign-born) populations, with concerns about low adherence rates in these patients compared to the host non-migrant population. Tackling MDR-TB in this context may, therefore, require unique approaches. We conducted a systematic review and meta-analysis to identify and synthesise data on MDR-TB treatment adherence in migrant patients to inform evidence-based strategies to improve care pathways and health outcomes in this group.

METHODS

This systematic review and meta-analysis was conducted in line with PRISMA guidelines (PROSPERO 42017070756). The databases Embase, MEDLINE, Global Health and PubMed were searched to 24 May 2017 for primary research reporting MDR-TB treatment adherence and outcomes in migrant populations, with no restrictions on dates or language. A meta-analysis was conducted using random-effects models.

RESULTS

From 413 papers identified in the database search, 15 studies reporting on MDR-TB treatment outcomes for 258 migrants and 174 non-migrants were included in the systematic review and meta-analysis. The estimated rate of adherence to MDR-TB treatment across migrant patients was 71% [95% confidence interval (CI) = 58-84%], with non-adherence reported among 20% (95% CI = 4-37%) of migrant patients. A key finding was that there were no differences in estimated rates of adherence [risk ratio (RR) = 1.05; 95% CI = 0.82-1.34] or non-adherence (RR = 0.97; 95% CI = 0.79-1.36) between migrants and non-migrants.

CONCLUSIONS

MDR-TB treatment adherence rates among migrants in high-income low-TB-incidence countries are approaching global targets for treatment success (75%), and are comparable to rates in non-migrants. The findings highlight that only just over 70% of migrant and non-migrant patients adhere to MDR-TB treatment. The results point to the importance of increasing adherence in all patient groups, including migrants, with an emphasis on tailoring care based on social risk factors for poor adherence. We believe that MDR-TB treatment targets are not ambitious enough.

High Rates of Treatment Success in Pulmonary Multidrug-Resistant Tuberculosis by Individually Tailored Treatment Regimens

RATIONALE

We evaluated whether treatment outcomes for patients with multidrug-resistant and extensively drug-resistant tuberculosis can be substantially improved when sufficient resources for personalizing medical care are available.

OBJECTIVES

To describe the characteristics and outcomes of patients with pulmonary multidrug-resistant tuberculosis at the Otto Wagner Hospital in Vienna, Austria.

METHODS

We conducted a retrospective single-center study of patients initiated on treatment for multi-drug resistant tuberculosis between January 2003 and December 2012 at the Otto Wagner Hospital, Vienna, Austria. The records of patients with multidrug-resistant tuberculosis were reviewed for epidemiological, clinical, laboratory, treatment, and outcome data.

MEASUREMENTS AND MAIN RESULTS

Ninety patients with pulmonary multidrug-resistant tuberculosis were identified. The median age was 30 years (interquartile range, 26-37). All patients were of non-Austrian origin, and 70 (78%) came from former states of the Soviet Union. Thirty-nine (43%) patients had multidrug-resistant tuberculosis; 28 (31%) had additional bacillary resistance to at least one second-line injectable drug and 9 (10%) to a fluoroquinolone. Fourteen (16%) patients had extensively drug-resistant tuberculosis. Eighty-eight different drug combinations were used for the treatment of the 90 patients. Surgery was performed on 10 (11.1%) of the patients. Sixty-five (72.2%) patients had a successful treatment outcome, 8 (8.9%) defaulted, 3 (3.3%) died, 8 (8.9%) continued treatment in another country and their outcome was unknown, and 6 (6.7%) were still on therapy. None of the patients experienced treatment failure. Treatment outcomes for patients with extensively drug-resistant tuberculosis were similar to those of patients with multidrug-resistant tuberculosis.

CONCLUSIONS

High rates of treatment success can be achieved in patients with multidrug-resistant and extensively drug-resistant tuberculosis when individually tailored treatment regimens can be provided in a high-resource setting.

Should all suspected tuberculosis cases in high income countries be tested with GeneXpert?

In countries with a low incidence of multidrug-resistant tuberculosis (MDR-TB), universal testing with GeneXpert might not be always cost-effective. This study provides hospital managers in low MDR-TB incidence countries with criteria on when decentralised universal GeneXpert testing would make sense. The alternatives taken into consideration include: universal microbiological culture and drug susceptibility testing (DST) only (comparator); as above but with concurrent centralized GeneXpert in a referral laboratory vs a decentralized GeneXpert system in every hospital to test smear-positive cases only; as above but testing all samples with GeneXpert regardless of smear status. The parameters were from the national TB statistics for England and from a systematic review. Decentralised GeneXpert to test any suspected TB case was the most cost-effective option when 6% or more TB patients belonged to the high-risk group, defined as previous TB diagnosis and or being born in countries with a high MDR-TB incidence. Hospital managers in England and other low MDR-TB incidence countries could use these findings to decide when to invest in GeneXpert or other molecular diagnostics with similar performance criteria for TB diagnostics.

Proceedings from the CIHLMU 5th Infectious Diseases Symposium 2016 "Drug Resistant Tuberculosis: Old Disease - New Challenge"

The 5th CIH^LMU Infectious Disease Symposium, Munich, Germany, March 12, 2016 brought together Tuberculosis Experts from developed and low middle-income countries to discuss the control of drug resistance Tuberculosis. The meeting featured 9 presentations: Tuberculosis history and current scenario, Tuberculosis and migration - current scenario in Germany, Mechanism of Tuberculosis resistance development, Epidemiology of resistance - transmission vs. new generation of resistance, The impact of diagnostic in patients beyond - sensitivity and specificity, The Bangladesh regimen - new hope trough old drugs, New drugs and regimens - an overview on studies and Multi and Extensively Drug Resistant Tuberculosis from Europe. The presentations were followed by a panel discussion. Serious Multidrug Resistance epidemic in some countries may jeopardize the progress in Tuberculosis control. In this meeting epidemiology, mechanism, immigration and screening, diagnosis, research and treatment of drug resistant tuberculosis were discussed.

Adverse Effects and Choice between the Injectable Agents Amikacin and Capreomycin in Multidrug-Resistant Tuberculosis

The prolonged use of injectable agents in a regimen for the treatment of multidrug-resistant tuberculosis (MDR-TB) is recommended by the World Health Organization, despite its association with ototoxicity and nephrotoxicity. We undertook this study to look at the relative adverse effects of capreomycin and amikacin. We reviewed the case notes of 100 consecutive patients treated at four MDR-TB treatment centers in the United Kingdom. The median total duration of treatment with an injectable agent was 178 days (interquartile range [IQR], 109 to 192 days; n = 73) for those with MDR-TB, 179 days (IQR, 104 to 192 days; n = 12) for those with MDR-TB plus fluoroquinolone resistance, and 558 days (IQR, 324 to 735 days; n = 8) for those with extensively drug-resistant tuberculosis (XDR-TB). Injectable use was longer for those started with capreomycin (183 days; IQR, 123 to 197 days) than those started with amikacin (119 days; IQR, 83 to 177 days) (P = 0.002). Excluding patients with XDR-TB, 51 of 85 (60%) patients were treated with an injectable for over 6 months and 12 of 85 (14%) were treated with an injectable for over 8 months. Forty percent of all patients discontinued the injectable due to hearing loss. Fifty-five percent of patients experienced ototoxicity, which was 5 times (hazard ratio [HR], 5.2; 95% confidence interval [CI], 1.2 to 22.6; P = 0.03) more likely to occur in those started on amikacin than in those treated with capreomycin only. Amikacin was associated with less hypokalemia than capreomycin (odds ratio, 0.28; 95% CI, 0.11 to 0.72), with 5 of 37 (14%) patients stopping capreomycin due to recurrent electrolyte loss. There was no difference in the number of patients experiencing a rise in the creatinine level of >1.5 times the baseline level. Hearing loss is frequent in this cohort, though its incidence is significantly lower in those starting capreomycin, which should be given greater consideration as a first-line agent.

Recent controversies about MDR and XDR-TB: Global implementation of the WHO shorter MDR-TB regimen and bedaquiline for all with MDR-TB?

Tuberculosis (TB) is now the biggest infectious disease killer worldwide. Although the estimated incidence of TB has marginally declined over several years, it is out of control in some regions including in Africa. The advent of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) threatens to further destabilize control in several regions of the world. Drug-resistant TB constitutes a significant threat because it underpins almost 25% of global TB mortality, is associated with high morbidity, is a threat to healthcare workers and is unsustainably costly to treat. The advent of highly resistant TB with emerging bacillary resistance to newer drugs has raised further concern. Encouragingly, in addition to preventative strategies, several interventions have recently been introduced to curb the drug-resistant TB epidemic, including newer molecular diagnostic tools, new (bedaquiline and delamanid) and repurposed (linezolid and clofazimine) drugs and shorter and individualized treatment regimens. However, there are several controversies that surround the use of new drugs and regimens, including whether, how and to what extent they should be used, and who specifically should be treated so that outcomes are optimally improved without amplifying the burden of drug resistance, and other potential drawbacks, thus sustaining effectiveness of the new drugs. The equipoise surrounding these controversies is discussed and some recommendations are provided.

Adverse Events Associated with Treatment of Multidrug-Resistant Tuberculosis in China: An Ambispective Cohort Study

Background

Adverse events are under-appreciated negative consequences that are significant clinical problems for patients undergoing anti-MDR-TB treatment due to longer duration of treatment and more need for concurrent use of multiple second-line drugs.

The aim of this study was to determine the incidence of adverse events and their impact on MDR-TB therapy and treatment outcome, and to identify possible drug-event pairs in China.

Material/Methods

An ambispective cohort study was conducted based on hospital medical records, which included a retrospective study that enrolled 751 MDR-TB patients receiving standardized regimen between May 2009 and July 2013, and a follow-up investigation of treatment outcome conducted in December 2016 in China. Adverse events were determined according to laboratory results or clinical criteria. Cox’s proportional hazards regression models were used for evaluating associations.

Results

There were 681(90.7%) patients experienced at least 1 type of adverse event and 55.2% of them required a changed MDR-TB treatment; 51(6.8%) patients required permanent discontinuation of the offending drug due to adverse events. The occurrence of adverse events was associated with poor treatment outcome (adjusted hazard ratio, 1.54; 95% CI 1.21, 1.87). A total of 10 different drug-event pairs were identified.

Conclusions

Adverse events occurred commonly during MDR-TB treatment in China, and often resulted in MDR-TB treatment change. The occurrence of adverse events affected MDR-TB poor outcome after treatment.

An updated systematic review and meta-analysis for treatment of multidrug-resistant tuberculosis

This systematic review aimed to update the current evidence for multidrug-resistant tuberculosis (MDR-TB) treatment.We searched for studies that reported treatment information and clinical characteristics for at least 25 patients with microbiologically confirmed pulmonary MDR-TB and either end of treatment outcomes, 6-month culture conversion or severe adverse events (SAEs). We assessed the association of these outcomes with patients' characteristics or treatment parameters. We identified 74 studies, including 17 494 participants.The pooled treatment success was 26% in extensively drug-resistant TB (XDR-TB) patients and 60% in MDR-TB patients. Treatment parameters such as number or duration and individual drugs were not associated with improved 6-month sputum culture conversion or end of treatment outcomes. However, MDR-TB patients that received individualised regimens had higher success than patients who received standardised regimens (64% versus 52%; p<0.0.01). When reports from 20 cohorts were pooled, proportions of SAE ranged from 0.5% attributed to ethambutol to 12.2% attributed to para-aminosalicylic acid. The lack of significant associations of treatment outcomes with specific drugs or regimens may reflect the limitations of pooling the data rather than a true lack of differences in efficacy of regimens or individual drugs.This analysis highlights the need for stronger evidence for treatment of MDR-TB from better-designed and reported studies.

The epidemiology, pathogenesis, transmission, diagnosis, and management of multidrug-resistant, extensively drug-resistant, and incurable tuberculosis

Global tuberculosis incidence has declined marginally over the past decade, and tuberculosis remains out of control in several parts of the world including Africa and Asia. Although tuberculosis control has been effective in some regions of the world, these gains are threatened by the increasing burden of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. XDR tuberculosis has evolved in several tuberculosis-endemic countries to drug-incurable or programmatically incurable tuberculosis (totally drug-resistant tuberculosis). This poses several challenges similar to those encountered in the pre-chemotherapy era, including the inability to cure tuberculosis, high mortality, and the need for alternative methods to prevent disease transmission. This phenomenon mirrors the worldwide increase in antimicrobial resistance and the emergence of other MDR pathogens, such as malaria, HIV, and Gram-negative bacteria. MDR and XDR tuberculosis are associated with high morbidity and substantial mortality, are a threat to health-care workers, prohibitively expensive to treat, and are therefore a serious public health problem. In this Commission, we examine several aspects of drug-resistant tuberculosis. The traditional view that acquired resistance to antituberculous drugs is driven by poor compliance and programmatic failure is now being questioned, and several lines of evidence suggest that alternative mechanisms-including pharmacokinetic variability, induction of efflux pumps that transport the drug out of cells, and suboptimal drug penetration into tuberculosis lesions-are likely crucial to the pathogenesis of drug-resistant tuberculosis. These factors have implications for the design of new interventions, drug delivery and dosing mechanisms, and public health policy. We discuss epidemiology and transmission dynamics, including new insights into the fundamental biology of transmission, and we review the utility of newer diagnostic tools, including molecular tests and next-generation whole-genome sequencing, and their potential for clinical effectiveness. Relevant research priorities are highlighted, including optimal medical and surgical management, the role of newer and repurposed drugs (including bedaquiline, delamanid, and linezolid), pharmacokinetic and pharmacodynamic considerations, preventive strategies (such as prophylaxis in MDR and XDR contacts), palliative and patient-orientated care aspects, and medicolegal and ethical issues.

Discordance between patient and clinician reports of adverse reactions to MDR-TB treatment

SETTING

An urban out-patient clinic in Durban, South Africa, providing community-based treatment for drug-resistant tuberculosis (TB).

OBJECTIVE

To describe concordance between patient report and clinician documentation of adverse drug reactions (ADRs) to treatment for multidrug-resistant TB (MDR-TB).

DESIGN

ADRs were documented by interview using an 18-item symptom checklist and medical record data abstraction during a cross-sectional parent study with 121 MDR-TB patients, 75% of whom were co-infected with the human immunodeficiency virus. Concordance was analyzed using Cohen's κ statistic, Gwet's agreement coefficient (AC) 1, and McNemar's test.

RESULTS

ADRs were reported much more frequently in patient interviews (μ = 8.6) than in medical records (μ = 1.4). Insomnia was most common (67% vs. 2%), followed by peripheral neuropathy (65% vs. 18%), and confusion (61 vs. 4%). κ scores were very low, with the highest degree of concordance found in hearing loss (κ = 0.23), which was the only ADR not found to be significantly different between the two data sources (P = 0.34).

CONCLUSIONS

Our study showed a lack of concordance between patient report and clinician documentation of ADRs. These findings indicate the need for improved documentation of ADRs to better reflect patients' experiences during MDR-TB treatment. These data have important implications for country-level pharmacovigilance programs that rely on clinician documentation of ADRs for MDR-TB policy formation.

Drug resistant TB: UK multicentre study (DRUMS): Treatment, management and outcomes in London and West Midlands 2008-2014

OBJECTIVES

Detailed information regarding treatment practices and outcomes of MDR-TB treatment in the UK is required as a baseline for care improvements.

METHODS

100 consecutive cases between 2008 and 2014 were reviewed retrospectively at 4 MDR-TB treatment centres in England to obtain information on drug treatment choices, hospital admission duration and outcomes for MDR-TB.

RESULTS

Initial hospital admission was long, median 62.5 (IQR 20-106, n = 92) days, and 13% (12/92) of patients lost their home during this period. Prolonged admission was associated with pulmonary cases, cavities on chest radiograph, a public health policy of waiting for sputum culture conversion (CC) and loss of the patient's home. Sputum CC occurred at a median of 33.5 (IQR 16-55, n = 46) days. Treatment success was high (74%, 74/100) and mortality low (1%, 1/100). A significant proportion of the cohort had "neutral" results due to deportation and transfer overseas (12%, (12/100)). 14% (14/100) had negative outcomes for which poor adherence was the main reason (62%, 9/14).

CONCLUSIONS

Successful outcome is common in recognised centres and limited by adherence rather than microbiological failure. Duration of hospital admission is influenced by lack of suitable housing and some variation in public health practice. Wider access to long-term assisted living facilities could improve completion rates.

Population Pharmacokinetics of Bedaquiline and Metabolite M2 in Patients With Drug-Resistant Tuberculosis: The Effect of Time-Varying Weight and Albumin

Albumin concentration and body weight are altered in patients with multidrug‐resistant tuberculosis (MDR‐TB) and change during the long treatment period, potentially affecting drug disposition. We here describe the pharmacokinetics (PKs) of the novel anti‐TB drug bedaquiline and its metabolite M2 in 335 patients with MDR‐TB receiving 24 weeks of bedaquiline on top of a longer individualized background regimen. Semiphysiological models were developed to characterize the changes in weight and albumin over time. Bedaquiline and M2 disposition were well described by three and one‐compartment models, respectively. Weight and albumin were correlated, typically increasing after the start of treatment, and significantly affected bedaquiline and M2 plasma disposition. Additionally, age and race were significant covariates, whereas concomitant human immunodeficiency virus (HIV) infection, sex, or having extensively drug‐resistant TB was not. This is the first population model simultaneously characterizing bedaquiline and M2 PKs in its intended use population. The developed model will be used for efficacy and safety exposure‐response analyses.

Severe adverse events during second-line tuberculosis treatment in the context of high HIV Co-infection in South Africa: a retrospective cohort study

Background

According to the World Health Organization, South Africa ranks as one of the highest burden of TB, TB/HIV co-infection, and drug-resistant TB (DR-TB) countries. DR-TB treatment is complicated to administer and relies on the use of multiple toxic drugs, with potential for severe adverse drug reactions. We report the occurrence of adverse events (AEs) during a standardised DR-TB treatment regimen at two outpatient, decentralized, public-sector sites in Johannesburg, South Africa.

Methods

We reviewed medical records of the six-month intensive treatment phase for rifampicin-resistant (RR) TB patients registered May 2012 - December 2014. Patients contributed follow-up time until death, loss from treatment, censoring (6 months) or data extraction. A standardized regimen of kanamycin, moxifloxacin, ethionamide, terizidone, and pyrazinamide was used according to national guidelines. AEs were graded using the AIDS Clinical Trial Group scale. We present subhazard ratios from competing risk analysis for time to severe AE, accounting for mortality and loss from treatment.

Results

Across the two sites, 578 eligible patient files were reviewed. 36.7 % were categorized as low weight (≤50 kg) at DR-TB initiation. 76.0 % had no history of TB treatment prior to the current episode of RR TB. 26.8 % were diagnosed with RR TB while hospitalized, indicating poor clinical condition. 82.5 % of patients were also HIV positive, of whom 43.8 % were on ART prior to RR TB treatment and 32.1 % initiated ART with or after RR TB treatment. Median CD4 count was 114.5 (IQR: 45-246.5). Overall, 578 reports of AEs were captured for 204 patients (35.3 %) and 110 patients (19.0 %) had at least one severe AE reported. Patients with at least one AE experienced a median of 3 (IQR: 2-4) AEs per patient. HIV-positive patients with CD4 counts ≤100 cells/mm³ and those newly initiating ART were more likely to experience a severe AE (sHR: 2.76, 95 % CI: 1.30–5.84 and sHR: 3.07, 95 % CI: 1.46–6.46, respectively).

Conclusion

Severe AE are common during the first 6 months of RR TB treatment and HIV-positive patients newly initiating ART have the highest subdistribution hazard ratio for severe AE, accounting for the competing risks of death and loss from treatment.

Dilemma of managing asymptomatic children referred with 'culture-confirmed' drug-resistant tuberculosis

BACKGROUND

The diagnosis of drug-resistant tuberculosis (DR-TB) in children is challenging and treatment is associated with many adverse effects.

OBJECTIVE

We aimed to assess if careful observation, without initiation of second-line treatment, is safe in asymptomatic children referred with 'culture-confirmed' DR-TB.

SETTING

KwaZulu-Natal, South Africa-an area with high burdens of HIV, TB and DR-TB.

DESIGN, INTERVENTION AND MAIN OUTCOME MEASURES

We performed an outcome review of children with 'culture-confirmed' DR-TB who were not initiated on second-line TB treatment, as they were asymptomatic with normal chest radiographs on examination at our specialist referral hospital. Children were followed up every other month for the first year, with a final outcome assessment at the end of the study.

RESULTS

In total, 43 asymptomatic children with normal chest radiographs were reviewed. The median length of follow-up until final evaluation was 549 days (IQR 259-722 days); most (34; 83%) children were HIV uninfected. Resistance patterns included 9 (21%) monoresistant and 34 (79%) multidrug-resistant (MDR) strains. Fifteen children (35%) had been treated with first-line TB treatment, prior to presentation at our referral hospital. At the final evaluation, 34 (80%) children were well, 7 (16%) were lost to follow-up, 1 (2%) received MDR-TB treatment and 1 (2%) died of unknown causes. The child who received MDR-TB treatment developed new symptoms at the 12-month review and responded well to second-line treatment.

CONCLUSIONS

Bacteriological evaluation should not be performed in the absence of any clinical indication. If drug-resistant Mycobacterium tuberculosis is detected in an asymptomatic child with a normal chest radiograph, close observation may be an appropriate strategy, especially in settings where potential laboratory error and poor record keeping are constant challenges.

The effect of surgery on the outcome of treatment for multidrug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND

In 2014 only 50 % of multidrug-resistant tuberculosis (MDR-TB) patients achieved a successful treatment outcome. With limited options for medical treatment, surgery has re-emerged as an adjuvant therapeutic strategy. We conducted a systematic review and meta-analysis to assess the evidence for the effect of surgery as an adjunct to chemotherapy on outcomes of adults treated for MDR-TB.

METHODS

Databases and grey literature sources were searched using terms incorporating surgery and MDR-TB. No language or publication type limits were applied. Articles published pre-1990, without a comparator group, or reporting <10 surgical participants were excluded. Two-stage sifting in duplicate was employed. Data on WHO-defined treatment outcomes were abstracted into a standardised database. Study-level risk of bias was evaluated using standardised tools. Outcome-level evidence quality was assessed using GRADE. Forest plots were generated, random effects meta-analysis conducted, and heterogeneity assessed using the I(2) statistic.

RESULTS

Of 1024 unique citations identified, 62 were selected for full-text review and 15 retained for inclusion. A further four articles were included after bibliography/citation searching, and one additional unpublished manuscript was identified, giving 20 articles for final inclusion. Six were meta-analyses/systematic reviews and 14 were primary research articles (observational studies). From the 14 primary research articles, a successful outcome (cured/treatment completed) was reported for 81.9 % (371/453) and 59.7 % (1197/2006) in the surgical and non-surgical group respectively, giving a summary odds ratio of 2.62 (95 % confidence interval 1.94-3.54). Loss to follow-up and treatment failure were lower in the surgery group (both p = 0.01). Overall GRADE quality of evidence for all outcomes considered was "very low".

CONCLUSIONS

This meta-analysis suggests that surgery as an adjunct to chemotherapy is associated with improved treatment outcomes in MDR-TB patients. However, inherent limitations in observational study design, insufficient reporting, and lack of adjustment for confounders, led to grading of the evidence as very low quality. Data on rationale for surgical referral, subsequent outcomes and resource-limited settings are scarce, precluding evidence-based recommendations on the suitability of surgery by patient characteristics or setting. It is hoped that highlighted methodological and reporting gaps will encourage improved design and reporting of future surgical studies for MDR-TB.

Evaluation of community-based treatment for drug-resistant tuberculosis in Bangladesh

OBJECTIVE

Drug-resistant tuberculosis (TB) threatens global TB control because it is difficult to diagnose and treat. Community-based programmatic management of drug-resistant TB (cPMDT) has made therapy easier for patients, but data on these models are scarce. Bangladesh initiated cPMDT in 2012, and in 2013, we sought to evaluate programme performance.

METHODS

In this retrospective review, we abstracted demographic, clinical, microbiologic and treatment outcome data for all patients enrolled in the cPMDT programme over 6 months in three districts of Bangladesh. We interviewed a convenience sample of patients about their experience in the programme.

RESULTS

Chart review was performed on 77 patients. Sputum smears and cultures were performed, on average, once every 1.35 and 1.36 months, respectively. Among 74 initially culture-positive patients, 70 (95%) converted their cultures and 69 (93%) patients converted the cultures before the sixth month. Fifty-two (68%) patients had evidence of screening for adverse events. We found written documentation of musculoskeletal complaints for 16 (21%) patients, gastrointestinal adverse events for 16 (21%), hearing loss for eight (10%) and psychiatric events for four (5%) patients; conversely, on interview of 60 patients, 55 (92%) reported musculoskeletal complaints, 54 (90%) reported nausea, 36 (60%) reported hearing loss, and 36 (60%) reported psychiatric disorders.

CONCLUSIONS

The cPMDT programme in Bangladesh appears to be programmatically feasible and clinically effective; however, inadequate monitoring of adverse events raises some concern. As the programme is brought to scale nationwide, renewed efforts at monitoring adverse events should be prioritised.

The need to accelerate access to new drugs for multidrug-resistant tuberculosis

Approximately half a million people are thought to develop multidrug-resistant tuberculosis annually. Barely 20% of these people currently receive recommended treatment and only about 10% are successfully treated. Poor access to treatment is probably driving the current epidemic, via ongoing transmission. Treatment scale-up is hampered by current treatment regimens, which are lengthy, expensive, poorly tolerated and difficult to administer in the settings where most patients reside. Although new drugs provide an opportunity to improve treatment regimens, current and planned clinical trials hold little promise for developing regimens that will facilitate prompt treatment scale-up. In this article we argue that clinical trials, while necessary, should be complemented by timely, large-scale, operational research that will provide programmatic data on the use of new drugs and regimens while simultaneously improving access to life-saving treatment. Perceived risks - such as the rapid development of resistance to new drugs - need to be balanced against the high levels of mortality and transmission that will otherwise persist. Doubling access to treatment and increasing treatment success could save approximately a million lives over the next decade.

Impact of lopinavir-ritonavir or nevirapine on bedaquiline exposures and potential implications for patients with tuberculosis-HIV coinfection

Concomitant treatment of tuberculosis (TB) and HIV is recommended and improves outcomes. Bedaquiline is a novel drug for the treatment of multidrug-resistant (MDR) TB; combined use with antiretroviral drugs, nevirapine, or ritonavir-boosted lopinavir (LPV/r) is anticipated, but no clinical data from coinfected patients are available. Plasma concentrations of bedaquiline and its M2 metabolite after single doses were obtained from interaction studies with nevirapine or LPV/r in healthy volunteers. The antiretrovirals' effects on bedaquiline and M2 pharmacokinetics were assessed by nonlinear mixed-effects modeling. Potential dose adjustments were evaluated with simulations. No significant effects of nevirapine on bedaquiline pharmacokinetics were identified. LPV/r decreased bedaquiline and M2 clearances to 35% (relative standard error [RSE], 9.2%) and 58% (RSE, 8.4%), respectively, of those without comedication. As almost 3-fold (bedaquiline) and 2-fold (M2) increases in exposures during chronic treatment with LPV/r are expected, dose adjustments are suggested for evaluation. Efficacious, safe bedaquiline dosing for MDR-TB patients receiving antiretrovirals is important. Modeling results suggest that bedaquiline can be coadministered with nevirapine without dose adjustments. The predicted elevation of bedaquiline and M2 levels during LPV/r coadministration may be a safety concern, and careful monitoring is recommended. Further data are being collected in coinfected patients to determine whether dose adjustments are needed. (These studies have been registered at ClinicalTrials.gov under registration numbers NCT00828529 [study C110] and NCT00910806 [study C117].).