Management of emerging multidrug-resistant tuberculosis in a low-prevalence setting

A case report of using gauze packing to treat postoperative chest bleeding after left pneumonectomy for secondary rifampicin-resistant tuberculosis

One patient with rifampin-resistant tuberculosis underwent emergency left pneumonectomy and thoracic gauze packing for hemoptysis due to recurrent hemoptysis after transcatheter arterial embolization. Vital signs were maintained by mechanical ventilation and medication. Tracheotomy and anti-tuberculosis treatment were performed. After half a year of follow-up, the patient's condition was stable.

Potential and weak links in the management of tuberculosis by Pakistani private pharmacy staff

Introduction

The emergence of MDR-TB is a global threat and an obstacle to the effective control of TB in Pakistan. A lack of proper TB knowledge among the staff in private pharmacies and the sale of compromised quality anti-TB drugs are the main instigators of multidrug-resistant tuberculosis (MDR-TB). Thus, this study was aimed at investigating the quality and storage conditions of fixed-dose combination (FDC) anti-TB drugs along with the awareness of staff working in private pharmacies regarding the identification of potential patients with TB and dispensing the inappropriate treatment regimens contributing to MDR-TB.

Methods

The study is completed in two phases. In phase I a cross-sectional study is performed using two quantitative research designs, i.e., exploratory and descriptive, to evaluate the knowledge of private pharmacy staff. The sample of 218 pharmacies was selected. While in phase II cross sectional survey is conducted in 10 facilities from where FDC anti TB drugs were sampled for analyzing their quality.

Result

Results revealed the presence of pharmacists only at 11.5% of pharmacies. Approximately 81% of staff at pharmacies had no awareness of MDR-TB, while 89% of pharmacies had no TB-related informative materials. The staff identified that most of the patients with TB (70%) were of poor socio-economic class, which restricted their purchase of four FDCs only up to 2–3 months. Only 23% were acquainted with the Pakistan National TB Program (NTP). Except for MDR-TB, the results showed a significant correlation between the experiences of staff with TB awareness. Findings from the quality evaluation of four FDC-TB drugs indicated that the dissolution and content assay of rifampicin were not according to the specifications, and overall, 30% of samples failed to comply with specifications. However, the other quality attributes were within the limits.

Conclusion

In light of the data, it can be concluded that private pharmacies could be crucial to the effective management of NTP through the timely identification of patients with TB, appropriate disease and therapy-related education and counseling, and proper storage and stock maintenance.

Linezolid for drug-resistant pulmonary tuberculosis

BACKGROUND

Linezolid was recently re-classified as a Group A drug by the World Health Organization (WHO) for treatment of multi-drug resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB), suggesting that it should be included in the regimen for all patients unless contraindicated. Linezolid use carries a considerable risk of toxicity, with the optimal dose and duration remaining unclear. Current guidelines are mainly based on evidence from observational non-comparative studies.

OBJECTIVES

To assess the efficacy of linezolid when used as part of a second-line regimen for treating people with MDR and XDR pulmonary tuberculosis, and to assess the prevalence and severity of adverse events associated with linezolid use in this patient group.

SEARCH METHODS

We searched the following databases: the Cochrane Infectious Diseases Specialized Register; CENTRAL; MEDLINE; Embase; and LILACS up to 13 July 2018. We also checked article reference lists and contacted researchers in the field.

SELECTION CRITERIA

We included studies in which some participants received linezolid, and others did not. We included randomized controlled trials (RCTs) of linezolid for MDR and XDR pulmonary tuberculosis to evaluate efficacy outcomes. We added non-randomized cohort studies to evaluate adverse events.Primary outcomes were all-cause and tuberculosis-associated death, treatment failure, and cure. Secondary outcomes were treatment interrupted, treatment completed, and time to sputum culture conversion. We recorded frequency of all and serious adverse events, adverse events leading to drug discontinuation or dose reduction, and adverse events attributed to linezolid, particularly neuropathy, anaemia, and thrombocytopenia.

DATA COLLECTION AND ANALYSIS

Two review authors (BS and DC) independently assessed the search results for eligibility and extracted data from included studies. All review authors assessed risk of bias using the Cochrane 'Risk of bias' tool for RCTs and the ROBINS-I tool for non-randomized studies. We contacted study authors for clarification and additional data when necessary.We were unable to perform a meta-analysis as one of the RCTs adopted a study design where participants in the study group received linezolid immediately and participants in the control group received linezolid after two months, and therefore there were no comparable data from this trial. We deemed meta-analysis of non-randomized study data inappropriate.

MAIN RESULTS

We identified three RCTs for inclusion. One of these studies had serious problems with allocation of the study drug and placebo, so we could not analyse data for intervention effect from it. The remaining two RCTs recruited 104 participants. One randomized 65 participants to receive linezolid or not, in addition to a background regimen; the other randomized 39 participants to addition of linezolid to a background regimen immediately, or after a delay of two months. We included 14 non-randomized cohort studies (two prospective, 12 retrospective), with a total of 1678 participants.Settings varied in terms of income and tuberculosis burden. One RCT and 7 out of 14 non-randomized studies commenced recruitment in or after 2009. All RCT participants and 38.7% of non-randomized participants were reported to have XDR-TB.Dosing and duration of linezolid in studies were variable and reported inconsistently. Daily doses ranged from 300 mg to 1200 mg; some studies had planned dose reduction for all participants after a set time, others had incompletely reported dose reductions for some participants, and most did not report numbers of participants receiving each dose. Mean or median duration of linezolid therapy was longer than 90 days in eight of the 14 non-randomized cohorts that reported this information.Duration of participant follow-up varied between RCTs. Only five out of 14 non-randomized studies reported follow-up duration.Both RCTs were at low risk of reporting bias and unclear risk of selection bias. One RCT was at high risk of performance and detection bias, and low risk for attrition bias, for all outcomes. The other RCT was at low risk of detection and attrition bias for the primary outcome, with unclear risk of detection and attrition bias for non-primary outcomes, and unclear risk of performance bias for all outcomes. Overall risk of bias for the non-randomized studies was critical for three studies, and serious for the remaining 11.One RCT reported higher cure (risk ratio (RR) 2.36, 95% confidence interval (CI) 1.13 to 4.90, very low-certainty evidence), lower failure (RR 0.26, 95% CI 0.10 to 0.70, very low-certainty evidence), and higher sputum culture conversion at 24 months (RR 2.10, 95% CI 1.30 to 3.40, very low-certainty evidence), amongst the linezolid-treated group than controls, with no differences in other primary and secondary outcomes. This study also found more anaemia (17/33 versus 2/32), nausea and vomiting, and neuropathy (14/33 versus 1/32) events amongst linezolid-receiving participants. Linezolid was discontinued early and permanently in two of 33 (6.1%) participants who received it.The other RCT reported higher sputum culture conversion four months after randomization (RR 2.26, 95% CI 1.19 to 4.28), amongst the group who received linezolid immediately compared to the group who had linezolid initiation delayed by two months. Linezolid was discontinued early and permanently in seven of 39 (17.9%) participants who received it.Linezolid discontinuation occurred in 22.6% (141/624; 11 studies), of participants in the non-randomized studies. Total, serious, and linezolid-attributed adverse events could not be summarized quantitatively or comparatively, due to incompleteness of data on duration of follow-up and numbers of participants experiencing events.

AUTHORS' CONCLUSIONS

We found some evidence of efficacy of linezolid for drug-resistant pulmonary tuberculosis from RCTs in participants with XDR-TB but adverse events and discontinuation of linezolid were common. Overall, there is a lack of comparative data on efficacy and safety. Serious risk of bias and heterogeneity in conducting and reporting non-randomized studies makes the existing, mostly retrospective, data difficult to interpret. Further prospective cohort studies or RCTs in high tuberculosis burden low-income and lower-middle-income countries would be useful to inform policymakers and clinicians of the efficacy and safety of linezolid as a component of drug-resistant TB treatment regimens.

First experience of effectiveness and safety of bedaquiline for 18 months within an optimised regimen for XDR-TB

Extensively drug-resistant (XDR) tuberculosis (TB) is a type of multidrug-resistant (MDR) TB that is resistant to isoniazid, rifampicin, fluoroquinolones and at least one injectable second-line drug. There are insufficient antibiotics for effective combination therapy and mortality exceeds 70% [1]. Following successful phase IIb trials [2] in 2013, the novel mycobacterial ATP-synthase inhibitor bedaquiline was approved in Europe and the USA for the first 24 weeks of MDR/XDR-TB treatment alongside a World Health Organization (WHO)-approved optimised background regimen. Phase III trials are ongoing but cohort data describe good early bacteriological outcomes in France [3, 4], Italy [5], the UK [6], the USA [7], India [8] and South Africa [9].

The first successful use of bedaquiline for 18 months for XDR-TB as part of an optimised background regimenhttp://ow.ly/XE34x

Linezolid in the Starter Combination for Multidrug-Resistant Tuberculosis: Time to Move on to Group Four?

Linezolid (LNZ), a group 5 antituberculous drug (unclear efficacy), was used in the starter regimens of 23 adults with multidrug-resistant tuberculosis. The LNZ-containing regimens were effective in achieving culture conversions and relapse-free outcomes. The most frequent LNZ-related side effect was neuropathy. We propose that LNZ should be reclassified among bactericidal second-line drugs.