Ethionamide Population Pharmacokinetic Model and Target Attainment in Multidrug-Resistant Tuberculosis

Ethionamide (ETA), an isonicotinic acid derivative, is part of the multidrug-resistant tuberculosis (MDR-TB) regimen. The current guidelines have deprioritized ETA because it is potentially less effective than other agents. Our aim was to develop a population pharmacokinetic (PK) model and simulate ETA dosing regimens in order to assess target attainment. This study included subjects from four different sites, including healthy volunteers and patients with MDR-TB. The TB centers included were two in the United States and one in Bangladesh. Patients who received ETA and had at least one drug concentration reported were included. The population PK model was developed, regimens with a total of 1,000 to 2,250 mg daily were simulated, and target attainment using published MICs and targets of 1.0-log kill and resistance suppression was assessed with the Pmetrics R package. We included 1,167 ethionamide concentrations from 94 subjects. The final population model was a one-compartment model with first-order elimination and absorption with a lag time. The mean (standard deviation [SD]) final population parameter estimates were as follows: absorption rate constant, 1.02 (1.11) h(-1); elimination rate constant, 0.69 (0.46) h(-1); volume of distribution, 104.16 (59.87) liters; lag time, 0.43 (0.32) h. A total daily dose of 1,500 mg or more was needed for >= 90% attainment of the 1.0-log kill target at a MIC of 1 mg/liter, and 2,250 mg/day led to 80% attainment of the resistance suppression target at a MIC of 0.5 mg/liter. In conclusion, we developed a population PK model and assessed target attainment for different ETA regimens. Patients may not be able to tolerate the doses needed to achieve the pre-defined targets supporting the current recommendations for ETA deprioritization

Diabetes-related tuberculosis in the Middle East: an urgent need for regional research

Objectives: Diabetes mellitus (DM) triples the risk of tuberculosis (TB) disease, complicates TB treatment, and increases the risk of a poor TB outcome. As DM prevalence is increasing across the Middle East, this review was performed to identify regional gaps in knowledge and research priorities for DM/TB. Methods: Online databases were searched for studies published from Middle East countries on DM and TB and the studies summarized based on topic and major findings. Studies included had a principle hypothesis related to both diseases, or described TB patients with individual data on DM. Results: Fifty-nine studies from 10 countries met search criteria. No published studies were found from Lebanon, Bahrain, Syria, Jordan, Cyprus, or the United Arab Emirates. DM prevalence among TB patients was high, but varied considerably across studies. The vast majority of studies were not specifically designed to compare DM/TB and non-DM/TB patients, but many suggested worse treatment outcomes for DM/TB, in accordance with reports from other regions. Conclusions: Opportunity exists for the regional study of bidirectional screening, management strategies for both DM and TB diseases, and whether such efforts could take place through the integration of services

Ultrasound-guided core biopsy in the diagnostic work-up of tuberculous lymphadenitis in Saudi Arabia, refining the diagnostic approach. Case series and review of literature

Summary: Objective: Tuberculous cervical lymphadenitis is the most common presentation of extrapulmonary tuberculosis (TB) in Saudi Arabia and worldwide. Obtaining a tissue biopsy for culture and histopathology is frequently needed to establish the diagnosis. The available diagnostic tools include excisional surgical biopsy, fine needle aspiration (FNA) and ultrasound-guided core lymph node biopsy. We present a single center experience of the use of ultrasound-guided core lymph node biopsy as a diagnostic tool for tuberculous lymphadenitis. Methods: A retrospective review of the interventional radiology database for all of the patients with cervical lymphadenopathy undergoing ultrasound-guided core biopsy at King Abdulaziz Medical City-Riyadh, Saudi Arabia from January 1 2008 to December 30 2011. The data were the patient demographics, clinical characteristics, biopsy method and pathological and clinical diagnoses. Results: Five cases underwent ultrasound-guided cervical lymph node biopsy during the study period. A total of 55 cases underwent excisional cervical lymph node biopsy in the same period. The age of the patients who underwent the core biopsy ranged from 18 to 76 years old. All of the biopsies were performed as one-day surgery, and all of the patients were discharged on the same day with no complications. The final diagnosis was confirmed in all of the cases (100%); with tuberculosis being the diagnosis in four of the five cases (80%), and one case being diagnosed as lymphoma. Conclusion: Ultrasound-guided core biopsy is an underutilized procedure in our hospital and could be a very valuable asset in the diagnostic algorithm of tuberculous lymphadenitis in Saudi Arabia. The widespread use of the procedure would positively affect patient care, providing earlier diagnosis and treatment. Keywords: Ultrasound-guided biopsy, Ultrasound-guided core biopsy, Ultrasound-guided lymph node biops

Fixed-dose combination associated with faster time to smear conversion compared to separate tablets of anti-tuberculosis drugs in patients with poorly controlled diabetes and pulmonary tuberculosis in Qatar

Abstract Background Diabetes is associated with increased risk of tuberculosis (TB) treatment failure, death, and relapse compared to patients without diabetes. Current TB regimens are available as fixed dose combination (FDC) and separate tablets (ST), in which using the former is purported to make it easier to adhere and complete treatment. So far there are no studies assessing the performance of FDC compared to ST in diabetic patients with pulmonary TB. Methodology A retrospective cohort study was conducted, and included eight hospitals in Qatar in which patients diagnosed with pulmonary TB received rifampin, isoniazid, pyrazinamide, and ethambutol (as FDC or ST) given as directly observed therapy. Sputum smears for acid fast bacilli were tested weekly. We included patients admitted between December 2012 and December 2015, ≥18 years old, diagnosed with TB with pretreatment positive sputum smears, and having diabetes. Patients with Mycobacterium tuberculosis that was resistant to any first-line drug were excluded. Blood glucose was monitored closely and controlled to < 180 md/dL using oral hypoglycemic agents and/or insulin. We assessed the effectiveness of TB regimens by comparing time to confirmed negative smears between those treated with FDC or ST, and the impact of adding metformin. Results 103 patients met inclusion criteria. Mean age and body mass index were 45.6 ± 9.1 years and 22.1 ± 3.6 kg/m2, respectively. Fifty-four (52%) patients received the FDC. There was no difference between groups in baseline characteristics and sputum bacillary loads. Patients prescribed FDC showed faster times to sputum smear conversion compared to ST (32 ± 19 vs. 46 ± 31 days, p = 0.01). The difference was greater among patients with pretreatment bacillary load of 3+ (FDC 36.6 ± 19.5 vs. ST 56.1 ± 28.8, p = 0.008). Receipt of metformin≥2000 mg/day altered the difference in time to smear conversion (FDC 30.7 ± 13.4 vs. ST 62 ± 35.5, p = 0.016), which was of greatest difference in those with pretreatment bacillary load 3+ and who received metformin≥2000 mg/day (FDC 36 ± 12.1 vs. ST 92.2 ± 26 days, p = 0.001). Conclusion Patients with diabetes and prescribed FDC showed faster smear conversion during treatment for pulmonary TB compared to ST which was more pronounced in those with 3+ bacillary load pretreatment and which appeared to be modified by higher dose metformin

Impact of early diagnosis of impaired glucose regulation in tuberculosis: Comparison of clinical outcomes in people with tuberculosis in Tanzania

This research article was published by John Wiley & Sons, Inc., 2022Objective Diabetes mellitus (DM) has been known to compromise tuberculosis (TB) treatment outcomes. Association data are limited for early hyperglycaemia detection and TB treatment outcomes. Thus, we assessed treatment outcomes including time to sputum conversion and death in TB participants with or without hyperglycaemia. Methods A prospective cohort study recruited TB participants receiving anti-TB treatment at health facilities in Tanzania between October 2019 and September 2020. Hyperglycaemia was defined as having pre-existing DM or pre-treatment random blood glucose of ≥7.8mmol/L, in combination categorised as impaired glucose regulation (IGR). Those with IGR were further screened for hyperglycaemia severity using glycated haemoglobin. In case of unknown status, participants were tested for HIV. Time to death was determined at 6 months of TB treatment. Results Of 1,344 participants, 187 (13.9%) had IGR, of whom 44 (23.5%) were HIV co-infected. Overall treatment success was 1,206 (89.7%), and was similar among participants with or without IGR (p>0.05). Time to death for participants with and without IGR was 18 versus 28 days (p=0.870), respectively. Age ≥40 years (p=0.038), bacteriological positive (p=0.039), HIV (p=0.009), or recurrent TB (p=0.017) predicted death or treatment success during TB treatment in adjusted multivariable models. Conclusion IGR did not influence clinical outcomes in TB patients with or without IGR in a programme of early IGR diagnosis and integration TB, HIV and DM care. Early detection and co-management of multi-morbidities among people diagnosed with TB may reduce likelihood of poor treatment outcomes in a programmatic setting

Clinical-demographic markers for improving diabetes mellitus diagnosis in people with tuberculosis in Tanzania

BACKGROUND: Tuberculosis (TB) control is threatened by an increasing prevalence of diabetes mellitus (DM), particularly in endemic countries. Screening for DM is not routinely implemented in Tanzania; therefore, we aimed to screen for DM at TB diagnosis using clinical-demographic markers. METHODS: Our cross-sectional study recruited TB patients who received anti-TB treatment between October 2019 and September 2020 at health care facilities in three regions from Tanzania. Patients were screened for DM using DM symptoms (polydipsia, polyphagia and polyuria) and random blood glucose (RBG) testing. Patients with a history of DM and those with no history of DM but an RBG ≥ 7.8 mmol/L had point-of-care glycated haemoglobin (HbA1c) testing, and were considered to have DM if HbA1c was ≥ 48 mmol/mol. RESULTS: Of 1344 TB patients, the mean age was 41.0 (± 17.0) years, and 64.7% were male. A total of 1011 (75.2%) had pulmonary TB, and 133 (10.4%) had at least one DM symptom. Overall, the prevalence of DM was 7.8%, of which 36 (2.8%) TB patients with no history of DM were newly diagnosed with DM by RBG testing. TB/DM patients were older than those with only TB (50.0 ± 14.0 years vs 40.0 ± 17.0 years, p < 0.001). Patients with RBG ≥ 7.8 mmol/L were more likely to have pulmonary TB (p = 0.003), age ≥ 35 years (p = 0.018), and have at least one DM symptom (p < 0.001). There was a substantial agreement (Kappa = 0.74) between the on-site glucometer and point-of-care HbA1c tests in detecting DM range of hyperglycemia. CONCLUSION: The implementation of clinical-demographic markers and blood glucose screening identified the overall prevalence of DM and those at risk of DM in TB patients. Clinical-demographic markers are independent predictors for DM range hyperglycemia and highlight the importance of further diagnostic testing and early co-management of TB and DM