Impact of Fluoroquinolone Use on Mortality Among a Cohort of Patients With Suspected Drug-Resistant Tuberculosis

Predictors of mortality in patients with drug-resistant tuberculosis: A systematic review and meta-analysis

BACKGROUND

Even though the lives of millions have been saved in the past decades, the mortality rate in patients with drug-resistant tuberculosis is still high. Different factors are associated with this mortality. However, there is no comprehensive global report addressing these risk factors. This study aimed to determine the predictors of mortality using data generated at the global level.

METHODS

We systematically searched five electronic major databases (PubMed/Medline, CINAHL, EMBASE, Scopus, Web of Science), and other sources (Google Scholar, Google). We used the Joanna Briggs Institute Critical Appraisal tools to assess the quality of included articles. Heterogeneity assessment was conducted using the forest plot and I2 heterogeneity test. Data were analyzed using STATA Version 15. The pooled hazard ratio, risk ratio, and odd's ratio were estimated along with their 95% CIs.

RESULT

After reviewing 640 articles, 49 studies met the inclusion criteria and were included in the final analysis. The predictors of mortality were; being male (HR = 1.25,95%CI;1.08,1.41,I2;30.5%), older age (HR = 2.13, 95%CI;1.64,2.62,I2;59.0%,RR = 1.40,95%CI; 1.26, 1.53, I2; 48.4%) including a 1 year increase in age (HR = 1.01, 95%CI;1.00,1.03,I2;73.0%), undernutrition (HR = 1.62,95%CI;1.28,1.97,I2;87.2%, RR = 3.13, 95% CI; 2.17,4.09, I2;0.0%), presence of any type of co-morbidity (HR = 1.92,95%CI;1.50-2.33,I2;61.4%, RR = 1.61, 95%CI;1.29, 1.93,I2;0.0%), having diabetes (HR = 1.74, 95%CI; 1.24,2.24, I2;37.3%, RR = 1.60, 95%CI;1.13,2.07, I2;0.0%), HIV co-infection (HR = 2.15, 95%CI;1.69,2.61, I2; 48.2%, RR = 1.49, 95%CI;1.27,1.72, I2;19.5%), TB history (HR = 1.30,95%CI;1.06,1.54, I2;64.6%), previous second-line anti-TB treatment (HR = 2.52, 95% CI;2.15,2.88, I2;0.0%), being smear positive at the baseline (HR = 1.45, 95%CI;1.14,1.76, I2;49.2%, RR = 1.58,95%CI;1.46,1.69, I2;48.7%), having XDR-TB (HR = 2.01, 95%CI;1.50,2.52, I2;60.8%, RR = 2.44, 95%CI;2.16,2.73,I2;46.1%), and any type of clinical complication (HR = 2.98, 95%CI; 2.32, 3.64, I2; 69.9%). There are differences and overlaps of predictors of mortality across different drug-resistance categories. The common predictors of mortality among different drug-resistance categories include; older age, presence of any type of co-morbidity, and undernutrition.

CONCLUSION

Different patient-related demographic (male sex, older age), and clinical factors (undernutrition, HIV co-infection, co-morbidity, diabetes, clinical complications, TB history, previous second-line anti-TB treatment, smear-positive TB, and XDR-TB) were the predictors of mortality in patients with drug-resistant tuberculosis. The findings would be an important input to the global community to take important measures.

Comparative in vitro susceptibility of a novel fluoroquinolone antibiotic candidate WFQ-228, levofloxacin, and moxifloxacin against Mycobacterium tuberculosis

OBJECTIVE

WFQ-228 is a novel developed fluoroquinolone (FQ) displaying potent antimicrobial activity against various clinical isolates of pathogens, including FQ-resistant isolates. The aim was to comparatively analyze in vitro susceptibilities of WFQ-228, levofloxacin (LFX), and moxifloxacin (MFX) against Mycobacterium tuberculosis (MTB) isolates, especially with gyrA mutations.

METHODS

We selected a panel of 75 MTB isolates, consisting of 25 FQ-susceptible and 50 FQ-resistant isolates determined by conventional drug susceptibility testing. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of FQs to MTB isolates were assessed.

RESULTS

MFX exhibited the most potent activity against FQ-susceptible MTB, demonstrating a MIC₅₀ of 0.031 mg/L, which was lower than that of LFX and WFQ-228. Against FQ-resistant MTB isolates, the MIC₅₀ of WFQ-228 was higher than that of MFX but lower than that of LFX. For WFQ-228, there was a significant overlap existing in the MIC distributions between the probable susceptible (PS) and probable resistant (PR) groups. Six out of 50 PR isolates were classified as susceptible based on a proposed critical concentration (CC) of 0.5 mg/L, yielding a poor sensitivity of 88.0%. These discordant isolates had GyrA substitution in Ala90Val, Ser91Pro, and Asp94Tyr. Additionally, MFX exhibited bactericidal activity against MTB isolates without gyrA mutations, which was significantly higher than that of isolates with gyrA mutations.

CONCLUSION

WFQ-228 is more efficacious than LFX in isolates with specific mutations conferring low-level FQ resistance. The bactericidal effect is noted more frequently in FQ-susceptible isolates than FQ-resistant isolates for MFX.

Predictors of mortality among multidrug-resistant tuberculosis patients in central Ethiopia: a retrospective follow-up study

The burden of multidrug-resistant tuberculosis (MDR-TB) related to mortality in resource-poor countries remains high. This study aimed to estimate the incidence and predictors of death among MDR-TB patients in central Ethiopia. A retrospective follow-up study was conducted at three hospitals in the Amhara region on 451 patients receiving treatment for MDR-TB from September 2010 to January 2017. Data were collected from patient registration books, charts and computer databases. Data were fitted to a parametric frailty model and survival was expressed as an adjusted hazard ratio (AHR) with a 95% confidence interval (CI). The median follow-up time of participants was 20 months (interquartile range: 12, 22) and 46 (10.20%) of patients died during this period. The incidence rate of mortality was 7.42 (95% CI 5.56-9.91)/100 person-years. Older age (AHR = 1.04, 95% CI 1.01-1.08), inability to self-care (AHR = 13.71, 95% CI 5.46-34.40), co-morbidity (AHR = 5.74, 95% CI 2.19-15.08), low body mass index (AHR = 4.13, 95% CI 1.02-16.64), acute lung complications (AHR = 4.22, 95% CI 1.66-10.70) and lung consolidation at baseline (AHR = 5.27, 95% CI 1.06-26.18) were independent predictors of mortality. Most of the identified predictor factors of death in this study were considered to be avoidable if the TB programme had provided nutritional support for malnourished patients and ensured a close follow-up of the elderly, and patients with co-morbidities.

Survival of patients with multidrug-resistant tuberculosis in Central China: a retrospective cohort study

The aim of this study was to evaluate long-term survival and risk factors associated with multidrug-resistant tuberculosis (MDR-TB) patient survival in Central China. Between December 2006 and June 2011, incident and retreatment adult MDR-TB patients were enrolled in the present study. Cox proportional hazard regression analysis was used to evaluate the risk factors affecting survival. The total follow-up period was 270 person-years (PY) for 356 MDR-TB cases in Wuhan. Of the 356 cases, 103 patients died, yielding an average case fatality rate of 381.2 per 1000 TB patients per year. Using adjusted Cox regression analysis, older age (adjusted hazard ratio (aHR) >3.0 starting from 30 years) and low education level (primary and middle school; aHR 1.67 (95% CI 1.01–2.77)) were independently associated with lower survival. Diabetes mellitus profoundly affected the survival of MDR-TB patients (aHR 1.95 (95% CI 1.30–2.93)). Our data demonstrate that coexistent diabetes significantly and negatively impacted MDR-TB patient survival. In addition, MDR-TB patients aged 60 years or older exhibited a greater risk of mortality during follow-up. Our findings emphasise that MDR-TB patients with comorbidities that increase their risk of death require additional medical interventions to reduce mortality.

Clinical predictors of drug-resistant tuberculosis in Mexico

Drug-resistant tuberculosis (DR-TB) remains a major global health problem. Early treatment of TB is critical; in the absence of rapid- susceptibility testing, the empiric selection of drugs should be guided by clinical data. This study aimed to determine the clinical predictors of DR-TB. From September 2010 to August 2017, sociodemographic and clinical characteristics were collected from 144 patients with tuberculosis at the Hospital Civil de Guadalajara, Mexico. Isolates were subjected to drug-susceptibility testing. Clinical predictors of DR-TB were determined using univariate and multivariate analysis. Any drug, isoniazid, and rifampin resistance rates were 47.7, 23.0, and 11.6%, respectively. The visualization of cavities and nodules through either chest radiography or computed tomography were independent predictors of DR-TB. In conclusion, early detection of DR-TB in this population could be based on multiple cavities being observed using chest imaging. This study’s results can be applied to future patients with TB in our community to optimize the DR-TB diagnostic process.

Clinical impact of using fluoroquinolone with low antimycobacterial activity on treatment delay in tuberculosis: Hospital-based and population-based cohort study

BACKGROUND/PURPOSE

Little remains known regarding whether newer FQ with less anti-mycobacterial activity (gemifloxacin) would reduce treatment delay.

METHODS

We identified one hospital-based cohort (HBC) and one population-based cohort (PBC) including patients receiving amoxicillin/clavulanate acid (Beta-lactam), gemifloxacin (Gemi), and fluoroquinolones other than gemifloxacin (Non-Gemi FQ) prior to TB treatment.

RESULTS

A total of 201 patients in the HBC and 3544 patients in the PBC were recruited. After 1:1 propensity score matching, TB treatment delay was statistically insignificant between Beta-lactam, Gemi group, and Non-Gemi FQ group in HBC (Beta-lactam vs Gemi: 22.3 ± 21.4 d vs 28.6 ± 27.9 d, p = 0.292; Beta-lactam vs Non-Gemi FQ: 33.3 ± 26.5 d vs 50.3 ± 47.3 d, p = 0.135) and PBC (Beta-lactam vs Gemi: 26.4 ± 29.1 vs 25.0 ± 28.1, p = 0.638; Beta-lactam vs Non-Gemi FQ: 29.4 ± 36.0 d vs 32.7 ± 35.0 d, p = 0.124, Non-Gemi FQ vs Gemi: 28.4 ± 33.0 d vs 25.0 ± 28.1 d, p = 0.29).

CONCLUSION

While limited by relatively low case number, our study showed that use of gemifloxacin neither results in nor reduces delay in TB treatment. The issue of FQ use on TB treatment delay was also not observed in our study. Early survey and maintaining high clinical alertness remains the key to reducing TB treatment delay.

Fluoroquinolones in Drug-Resistant Tuberculosis: Culture Conversion and Pharmacokinetic/Pharmacodynamic Target Attainment To Guide Dose Selection

Fluoroquinolones are group A drugs in tuberculosis guidelines. We aim to compare the culture conversion between new-generation (levofloxacin and moxifloxacin) and old-generation (ciprofloxacin and ofloxacin) fluoroquinolones, develop pharmacokinetic models, and calculate target attainment for levofloxacin and moxifloxacin. We included three U.S. tuberculosis centers.

Fluoroquinolones are group A drugs in tuberculosis guidelines. We aim to compare the culture conversion between new-generation (levofloxacin and moxifloxacin) and old-generation (ciprofloxacin and ofloxacin) fluoroquinolones, develop pharmacokinetic models, and calculate target attainment for levofloxacin and moxifloxacin. We included three U.S. tuberculosis centers. Patients admitted between 1984 and 2015, infected with drug-resistant tuberculosis, and who had received fluoroquinolones for ≥28 days were included. Demographics, sputum cultures and susceptibility, treatment regimens, and serum concentrations were collected. A time-to-event analysis was conducted, and Cox proportional hazards model was used to compare the time to culture conversion. Using additional data from ongoing studies, pharmacokinetic modelling and Monte Carlo simulations were performed to assess target attainment for different doses. Overall, 124 patients received fluoroquinolones. The median age was 40 years, and the median weight was 60 kg. Fifty-six patients (45%) received old-generation fluoroquinolones. New-generation fluoroquinolones showed a faster time to culture conversion (median 16 versus 40 weeks, P = 0.012). After adjusting for isoniazid and clofazimine treatment, patients treated with new-generation fluoroquinolones were more likely to have culture conversion (adjusted hazards ratio, 2.16 [95% confidence interval, 1.28 to 3.64]). We included 178 patients in the pharmacokinetic models. Levofloxacin and moxifloxacin were best described by a one-compartment model with first-order absorption and elimination. At least 1,500 to 1,750 mg levofloxacin and 800 mg moxifloxacin may be needed for maximum kill at the current epidemiologic cutoff values. In summary, new-generation fluoroquinolones showed faster time to culture conversion compared to the old generation. For optimal target attainment at the current MIC values, higher doses of levofloxacin and moxifloxacin may be needed.

Management of complex tuberculosis cases: a focus on drug-resistant tuberculous meningitis

INTRODUCTION

Drug-resistant tuberculous meningitis has been reported worldwide. Isoniazid mono-resistance is the most frequent cause of drug-resistant tuberculous meningitis, a life-threatening disease. Extensive drug-resistant tuberculous meningitis has also been reported in some isolated case reports. Areas covered: We reviewed the current literature on drug-resistant tuberculous meningitis, as well as drug-resistant tuberculosis. Expert commentary: Drug-resistant tuberculous meningitis is a life-threatening disease and needs prompt diagnosis and treatment. Xpert MTB/RIF Ultra technology can detect Mycobacterium tuberculosis and rifampicin resistance in cerebrospinal fluid (CSF) even with low numbers of bacilli. The optimum antituberculosis drug regimen for multidrug-resistant tuberculous meningitis is largely unknown as no second-line antituberculosis drug-containing regimen has been tested in a randomized controlled fashion in drug-resistant tuberculous meningitis. A combination of levofloxacin, kanamycin, ethionamide, linezolid, and pyrazinamide would be an appropriate regimen because of excellent CSF profile of most of these drugs. End TB Strategy will help in checking the increasing challenge of drug-resistant tuberculous meningitis as it aims to eliminate all kinds of tuberculosis by the year 2035.

Limited Effect of Later-Generation Fluoroquinolones in the Treatment of Ofloxacin-Resistant and Moxifloxacin-Susceptible Multidrug-Resistant Tuberculosis

Recent data conflict on the clinical efficacy of later-generation fluoroquinolones, such as moxifloxacin or levofloxacin, for the treatment of multidrug-resistant tuberculosis (MDR-TB) that is resistant to ofloxacin but susceptible to moxifloxacin. The purpose of the present study was to evaluate whether later-generation fluoroquinolones can improve treatment outcomes in patients with ofloxacin-resistant, moxifloxacin-susceptible MDR-TB. A retrospective cohort study was performed on 208 patients with moxifloxacin-susceptible MDR-TB who were treated between 2006 and 2011. Later-generation fluoroquinolones were used for all patients. Overall, 171 patients (82%) had ofloxacin-susceptible, moxifloxacin-susceptible MDR-TB (ofloxacin-susceptible group), and 37 (18%) had ofloxacin-resistant, moxifloxacin-susceptible MDR-TB (ofloxacin-resistant group). Compared to the ofloxacin-susceptible group, the ofloxacin-resistant group was more likely to have a history of MDR-TB treatment (P < 0.001) and cavitary lesions on chest radiography (P < 0.001). In addition, the ofloxacin-resistant group was more likely than the ofloxacin-susceptible group to have resistance to the drugs pyrazinamide (P = 0.003), streptomycin (P = 0.015), prothionamide (P < 0.001), and para-aminosalicylic acid (P < 0.001). Favorable outcomes were more frequently achieved for the ofloxacin-susceptible group than for the ofloxacin-resistant group (91% [156/171] versus 57% [21/37], respectively [P < 0.001]). In multivariable regression logistic analysis, the ofloxacin-susceptible group was about 5.36 (95% confidence interval, 1.55 to 18.53) times more likely than the ofloxacin-resistant group (P < 0.001) to have favorable outcomes. Despite in vitro moxifloxacin susceptibility, the frequency of favorable treatment outcomes for ofloxacin-resistant MDR-TB was significantly lower than that for ofloxacin-susceptible MDR-TB, even when later-generation fluoroquinolones were used, indicating that more-aggressive therapies may be needed for ofloxacin-resistant MDR-TB.