Adverse Drug Reactions Associated with Anti-Tuberculosis Therapy

The pharmacovigilance has been evolved as a professional and ethical practice in ensuring the safety of medicines. The Adverse Drug Reactions (ADRs) associated with the use of medicines including Anti-Tuberculous Therapy (ATT) through a robust system of pharmacovigilance helps in promoting the safety of patients at large. The occurrence of ADRs associated with the use of ATT is expected, a large number of medicines are combined and used for prolonged duration. The suspected ADRs associated with first line ATT are well documented. However, the drugs used in second line or multidrug resistant to tuberculosis (TB), namely bedaquiline, reported to cause QT prolongation in electrocardiogram reading as one of the most common ADRs. Therefore, early identification and prevention of ADRs during ATT is essential for promoting the rational use and reduce the burden of anti-microbial resistance, besides achieving better treatment outcomes

Acquired rifampicin resistance in thrice-weekly antituberculosis therapy: impact of HIV and antiretroviral therapy

Risk factors for acquired rifampicin resistance (ARR) among tuberculosis patients on thrice-weekly antituberculosis therapy were baseline isoniazid resistance and HIV. Among HIV-infected patients, higher mycobacterial burden and lower CD4 count, but not highly active antiretroviral therapy, were significantly associated with ARR. Background: Risk factors for acquired rifampicin resistance (ARR) in human immunodeficiency virus (HIV)/tuberculosis coinfection, in the highly active antiretroviral therapy (HAART) era, needs evaluation. We studied the impact of HIV and HAART on ARR among patients taking thrice-weekly antituberculosis therapy. Methods: This cross-protocol analysis included patients with newly diagnosed, rifampicin-susceptible pulmonary tuberculosis, with and without HIV, enrolled in clinical trials (who took >80% of medication) at the National Institute for Research in Tuberculosis between 1999 and 2013. All patients received rifampicin and isoniazid for 6 months reinforced with pyrazinamide and ethambutol in the first 2 months, given thrice-weekly throughout the study along with HAART in one of the groups. Outcomes were categorized and multivariate logistic regression analysis performed to identify risk factors for ARR. Results: The per-protocol results included patients with tuberculosis: 246 HIV-uninfected patients (HIV–TB+), 212 HIV patients not on HAART (non-HAART), and 116 HIV-infected patients on HAART. Median CD4 counts of the latter 2 groups were 150 and 93 cells/μL, respectively, and the median viral loads were 147 000 and 266 000 copies/mL, respectively. Compared with HIV–TB+, the relative risks (RRs) for an unfavorable response in the coinfected, non-HAART and HAART groups were 2.1 (95% confidence interval [CI], 1.7–14.8; P<.0001) and 2.1 (95% CI, .9–5.2; P=.3), whereas for ARR, the RRs were 21.1 (95% CI, 2.6–184; P<.001) and 8.2 (95% CI, .6–104; P=.07), respectively. Conclusions: HIV-infected patients with tuberculosis treated with a thrice-weekly antituberculosis regimen are at a higher risk of ARR, compared with HIV-uninfected patients, in the presence of baseline isoniazid resistance. HAART reduces but does not eliminate the risk of ARR

Efficacy and safety of once-daily nevirapine- or efavirenz-based antiretroviral therapy in HIV-associated tuberculosis: a randomized clinical trial

Background: Nevirapine (NVP) can be safely and effectively administered once-daily but has not been assessed in human immunodeficiency virus (HIV)–infected patients with tuberculosis (TB). We studied the safety and efficacy of once-daily NVP, compared with efavirenz (EFV; standard therapy); both drugs were administered in combination with 2 nucleoside reverse-transcriptase inhibitors. Methods: An open-label, noninferiority, randomized controlled clinical trial was conducted at 3 sites in southern India. HIV-infected patients with TB were treated with a standard short-course anti-TB regimen (2EHRZ3/4RH3; [2 months of Ethambutol, Isoniazid, Rifampicin, Pyrazinamide/4 months of Isoniazid and Rifampicin] thrice weekly) and randomized to receive once-daily EFV at a dose of 600 mg or NVP at a dose of 400 mg (after 14 days of 200 mg administered once daily) with didanosine 250/400 mg and lamivudine 300 mg after 2 months. Sputum smears and mycobacterial cultures were performed every month. CD4+ cell count, viral load, and liver function test results were monitored periodically. Primary outcome was a composite of death, virological failure, default, or serious adverse event (SAE) at 24 weeks. Both intent-to-treat and per protocol analyses were done, and planned interim analyses were performed. Results: A total of 116 patients (75% [87 patients] of whom had pulmonary TB), with a mean age of 36 years, a median CD4+ cell count of 84 cells/mm3, and a median viral load of 310?000 copies/mL, were randomized. At 24 weeks, 50 of 59 patients in the EFV group and 37 of 57 patients in the NVP group had virological suppression (P = .024). There were no deaths, 1 SAE, and 5 treatment failures in the EFV arm, compared with 5 deaths, 2 SAEs, and 10 treatment failures in the NVP arm. The trial was halted by the data and safety monitoring board at the second interim analysis. Favorable TB treatment outcomes were observed in 93% of the patients in the EFV arm and 84% of the patients in the NVP arm (P = .058). Conclusions: Compared with a regimen of didanosine, lamivudine, and EFV, a regimen of once-daily didanosine, lamivudine, and NVP was inferior and was associated with more frequent virologic failure and death

Predictors of unfavorable responses to therapy in rifampicin-sensitive pulmonary tuberculosis using an integrated approach of radiological presentation and sputum mycobacterial burden

INTRODUCTION: Despite the exalted status of sputum mycobacterial load for gauging pulmonary tuberculosis treatment and progress, Chest X-rays supplement valuable information for taking instantaneous therapeutic decisions, especially during the COVID-19 pandemic. Even though literature on individual parameters is overwhelming, few studies have explored the interaction between radiographic parameters denoting severity with mycobacterial burden signifying infectivity. By using a sophisticated approach of integrating Chest X-ray parameters with sputum mycobacterial characteristics, evaluated at all the three crucial time points of TB treatment namely pre-treatment, end of intensive phase and completion of treatment, utilizing the interactive Cox Proportional Hazards model, we aimed to precisely deduce predictors of unfavorable response to TB treatment. MATERIALS AND METHOD: We extracted de-identified data from well characterized clinical trial cohorts that recruited rifampicin-sensitive Pulmonary TB patients without any comorbidities, taking their first spell of anti-tuberculosis therapy under supervision and meticulous follow up for 24 months post treatment completion, to accurately predict TB outcomes. Radiographic data independently obtained, interpreted by two experienced pulmonologists was collated with demographic details and, sputum smear and culture grades of participants by an independent statistician and analyzed using the Cox Proportional Hazards model, to not only adjust for confounding factors including treatment effect, but also explore the interaction between radiological and bacteriological parameters for better therapeutic application. RESULTS: Of 667 TB patients with data available, cavitation, extent of involvement, lower zone involvement, smear and culture grade at baseline were significant parameters predisposing to an unfavorable TB treatment outcome in the univariate analysis. Reduction in radiological lesions in Chest X-ray by at least 50% at 2 months and 75% at the end of treatment helped in averting unfavorable responses. Smear and Culture conversion at the end of 2 months was highly significant as a predictor (p2 zones, were 3.05 (95% CI: 1.12–8.23) and 1.92 (95% CI: 0.72–5.08) respectively. Patients without cavitation, zonal involvement 2 zones and 3+ smear grade individually and independently forecasted a poorer TB outcome. The interaction model revealed that Zonal involvement confined to 2 zones, without a cavity and smear grade up to 2+, constituting “minimal disease”, had a better prognosis. Radiological clearance >50% along with smear conversion at the end of intensive phase of treatment, observed to be a reasonable alternative to culture conversion in predicting a successful outcome. These parameters may potentially take up key positions as stratification factors for future trials contemplating on shorter TB regimens

Efficacy of a Six-Month versus a 36-Month Regimen for Prevention of Tuberculosis in HIV-Infected Persons in India: A Randomized Clinical Trial

<div><h3>Background</h3><p>The optimal duration of preventive therapy for tuberculosis (TB) among HIV-infected persons in TB-endemic countries is unknown.</p> <h3>Methods</h3><p>An open-label randomized clinical trial was performed and analyzed for equivalence. Seven hundred and twelve HIV-infected, ART-naïve patients without active TB were randomized to receive either ethambutol 800 mg and isoniazid 300 mg daily for six-months (6EH) or isoniazid 300 mg daily for 36-months (36H). Drugs were dispensed fortnightly and adherence checked by home visits. Patients had chest radiograph, sputum smear and culture performed every six months, in addition to investigations if they developed symptoms. The primary endpoint was incident TB while secondary endpoints were all-cause mortality and adverse events. Survival analysis was performed on the modified intent to treat population (m-ITT) and rates compared.</p> <h3>Findings</h3><p>Tuberculosis developed in 22 (6.4%) of 344 subjects in the 6EH arm and 13 (3.8%) of 339 subjects in the 36H arm with incidence rates of 2.4/100py (95%CI- 1.4–3.5) and 1.6/100py (95% CI-0.8–3.0) with an adjusted rate ratio (aIRR) of 1.6 (0.8–3.2). Among TST-positive subjects, the aIRR of 6EH was 1.7 (0.6–4.3) compared to 36H, p = 0.8. All-cause mortality and toxicity were similar in the two arms. Among 15 patients with confirmed TB, 4 isolates were resistant to isoniazid and 2 were multidrug-resistant.</p> <h3>Interpretation</h3><p>Both regimens were similarly effective in preventing TB, when compared to historical incidence rates. However, there was a trend to lower TB incidence with 36H. There was no increase in isoniazid resistance compared to the expected rate in HIV-infected patients.</p> <p>The trial is registered at ClinicalTrials.gov, NCT00351702.</p> </div

TB incidence and mortality rate among TST positive and negative subjects, by regimen (mITT population) and per protocol analysis.

<p>TB incidence and mortality rate among TST positive and negative subjects, by regimen (mITT population) and per protocol analysis.</p

Kaplan-Meier curves showing cumulative probability of survival without TB and death over 36 months by regimen, TST status, CD4 count and sex.

<p>The four top panels show cumulative survival without TB over 36 months by regimen (6EH versus 36H, ns), TST (<5 mm versus >5 mm, ns), CD4 count (<200 versus >200 cells/mm3, p<0.001) and sex (female versus male, p = 0.05). The four bottom panels show cumulative mortality over 36 months by regimen (6EH versus 36H, ns), TST (<5 mm versus >5 mm, ns), CD4 count (<200 versus >200 cells/mm3, p<0.001) and sex (female versus male, p<0.001).</p