Adverse effects of oral second-line antituberculosis drugs in children

Current Treatment of Drug-Resistant Tuberculosis in Children

Optimal diagnosis and management of children aged <15 y with rifampicin- or multidrug-resistant tuberculosis (RR/MDR-TB) relies on identification of adults with the disease and pro-active screening of their close contacts. Children may be diagnosed with RR/MDR-TB based on microbiological confirmation from clinical specimens (sputum, gastric washings, stool), but usually the diagnosis is presumptive, with a history of exposure to RR/MDR-TB and clinical/radiological signs and symptoms suggestive of TB disease. RR/MDR-TB should also be considered in children where first-line TB treatment fails despite good adherence to therapy. Composition and duration of all-oral RR/MDR-TB treatment regimens in children are based on site and severity of TB disease, drug resistance profile of the Mycobacterium tuberculosis strain (isolated from the child or from the most likely source patient), inclusion of at least four drugs considered to be effective (with priority given to World Health Organization Group A and B drugs), toxicity and tolerability of medications (and feasibility of adverse effect monitoring in the child's setting), and availability of child-friendly formulations of TB medications. Individualized RR/MDR-TB regimens are preferable to the standardised 9-12-mo regimen for children, and injectable agents must not be used. Optimal adherence to treatment relies on education, training and support for caregivers and others who are responsible for administering medications to children, as well as close clinical monitoring and early management of adverse effects. Children who are initiated on adequate RR/MDR-TB regimens have high treatment success rates, but efforts to find and treat more children with undiagnosed RR/MDR-TB are crucial to reduce childhood TB mortality.

Drug-induced hypothyroidism in tuberculosis

INTRODUCTION

Adverse reactions to tuberculosis treatment can impact patient adherence and prognosis. Hypothyroidism is a frequent adverse reaction caused using ethionamide, prothionamide, and para-aminosalicylic acid and is often underdiagnosed.

AREAS COVERED

We searched Scielo, Scopus, and EMBASE databases, including 67 articles. Antitubercular drug-induced hypothyroidism has a prevalence of 17%. It occurs after 2 to 3 months of treatment and resolves within 4 to 6 weeks after discontinuation. It is postulated to result from the inhibition of thyroperoxidase function, blocking thyroid hormone synthesis. Symptoms are nonspecific, necessitating individualized thyroid-stimulating hormone measurement for detection. Specific guidelines for management are lacking, but initiation of treatment with levothyroxine, as is customary for primary hypothyroidism, is recommended. Discontinuation of antitubercular drugs is discouraged, as it may lead to unfavorable consequences.

EXPERT OPINION

Antitubercular drug-induced hypothyroidism is more common than previously thought, affecting one in six MDR-TB patients. Despite diagnostic and treatment recommendations, implementation is hindered in low-income countries due to the lack of certified laboratories. New drugs for tuberculosis treatment may affect thyroid function, requiring vigilant monitoring for complications, including hypothyroidism.

Optimizing dosing of the cycloserine pro-drug terizidone in children with rifampicin-resistant tuberculosis

There are no pharmacokinetic data in children on terizidone, a pro-drug of cycloserine and a World Health Organization (WHO)-recommended group B drug for rifampicin-resistant tuberculosis (RR-TB) treatment. We collected pharmacokinetic data in children <15 years routinely receiving 15-20 mg/kg of daily terizidone for RR-TB treatment. We developed a population pharmacokinetic model of cycloserine assuming a 2-to-1 molecular ratio between terizidone and cycloserine. We included 107 children with median (interquartile range) age and weight of 3.33 (1.55, 5.07) years and 13.0 (10.1, 17.0) kg, respectively. The pharmacokinetics of cycloserine was described with a one-compartment model with first-order elimination and parallel transit compartment absorption. Allometric scaling using fat-free mass best accounted for the effect of body size, and clearance displayed maturation with age. The clearance in a typical 13 kg child was estimated at 0.474 L/h. The mean absorption transit time when capsules were opened and administered as powder was significantly faster compared to when capsules were swallowed whole (10.1 vs 72.6 min) but with no effect on bioavailability. Lower bioavailability (-16%) was observed in children with weight-for-age z-score below -2. Compared to adults given 500 mg daily terizidone, 2022 WHO-recommended pediatric doses result in lower exposures in weight bands 3-10 kg and 36-46 kg. We developed a population pharmacokinetic model in children for cycloserine dosed as terizidone and characterized the effects of body size, age, formulation manipulation, and underweight-for-age. With current terizidone dosing, pediatric cycloserine exposures are lower than adult values for several weight groups. New optimized dosing is suggested for prospective evaluation.

Hepatocellular Injury in Children Treated for Rifampicin-resistant Tuberculosis: Incidence, Etiology and Outcome

BACKGROUND

Hepatocellular injury has been reported commonly in adults on rifampicin-resistant and multidrug-resistant tuberculosis (RR/MDR-TB) treatment. However, there are limited data in children.

METHODS

Two pharmacokinetic studies of children (0-17 years) routinely treated for RR/MDR-TB were conducted in Cape Town, South Africa between October 2011 and February 2020. Hepatocellular injury adverse events (AEs; defined as elevated alanine aminotransferase [ALT]) were documented serially. Data were analyzed to determine the incidence, etiology, risk factors, management and outcome of ALT elevation.

RESULTS

A total of 217 children, median age 3.6 years (interquartile range, 1.7-7.1 years) at enrollment were included. The median follow-up time was 14.0 months (interquartile range, 9.8-17.2 months). Fifty-five (25.3%) patients developed an ALT AE. Of these, 43 of 55 (78%) patients had 54 ALT AEs attributed to their RR/MDR-TB treatment. The incidence rate of ALT AEs related to RR-TB treatment was 22.4 per 100 person-years. Positive HIV status and having an elevated ALT at enrollment were associated with time to ALT AE attributed to RR/MDR-TB treatment, with P values 0.0427 and P < 0.0001, respectively. Hepatitis A IgM was positive in 11 of 14 (78.6%) severe (grade ≥3) cases of ALT AEs. In 8 of 14 (57%) severe ALT AEs, hepatotoxic drugs were stopped or temporarily interrupted. None had a fatal or unresolved outcome.

CONCLUSIONS

Hepatocellular injury in children on RR/MDR-TB treatment is common, although usually mild; having elevated ALT early in treatment and HIV-positive status are possible risk factors. Hepatitis A was a common etiology of severe ALT AE in children treated for RR/MDR-TB.

New Drugs and Regimens for Tuberculosis Disease Treatment in Children and Adolescents

After almost 30 years of relative stagnation, research over the past decade has led to remarkable advances in the treatment of both drug-susceptible (DS) and drug-resistant (DR) tuberculosis (TB) disease in children and adolescents. Compared with the previous standard therapy of at least 6 months, 2 new regimens lasting for only 4 months for the treatment of DS-TB have been studied and are recommended by the World Health Organization (WHO), along with a shortened 6-month regimen for treatment of DS-TB meningitis. In addition, the 18- to 24-month regimens previously used for DR-TB that included painful injectable drugs with high rates of adverse effects have been replaced with shorter, safer all-oral regimens. Advances that have improved treatment include development of new TB drugs (bedaquiline, delamanid, pretomanid), reapplication of older TB drugs (rifampicin and rifapentine), and repurposing of other drugs (clofazimine and linezolid). The development of child-friendly formulations for many of these drugs has further enhanced the ability to safely and effectively treat DS- and DR-TB in children and adolescents. The characteristics and use of these drugs, regimens, and formulations are reviewed.

Frequency and Management of Adverse Drug Reactions Among Drug-Resistant Tuberculosis Patients: Analysis From a Prospective Study

Drug-resistant tuberculosis (DR-TB) management is often linked with a higher rate of adverse drug reactions (ADRs) needing effective and timely management of these ADRs, which, if left untreated, may result in a higher rate of loss to follow-up of drug-resistant patients.

Study objective: The study was aimed at prospectively identifying the nature, frequency, suspected drugs, and management approaches for ADRs along with risk factors of ADRs occurrence among DR-TB patients at Nishtar Medical University, Hospital, Multan, Pakistan.

Materials and Methods: The prospective study included all the DR-TB patients enrolled for treatment from January 2016 to May 2017 at the study site. Patients were evaluated for the treatment-induced ADRs as per standard criteria of the National Tuberculosis Program, Pakistan. Multivariate logistic regression was used to assess the independent variables associated with the occurrence of ADRs.

Results: Out of 271 DR-TB patients included in the final analysis, it was observed that 55 patients (20.3%) experienced at least three ADRs. A total of 50 (18.5%) patients experienced zero adverse effects, while 15 (5.5%), 33 (12.2%), and 53 (19.6%) patients experienced one, two, and four ADRs, respectively. Gastrointestinal disturbances (66.7%), nervous system disorders (59.4%), and electrolyte disturbances (55.7%) remained the highest reported ADRs during therapy, followed by arthralgia (49.1%), ototoxicity (24%), pruritic reactions/rash (12.9%), dyspnoea (12.5%), and tinnitus (8.8%). Pulmonary cavitation at the baseline visit (p-value 0.001, OR 3.419; 95% CI (1.694–6.902) was significantly associated with the occurrence of ADRs among DR-TB patients.

Conclusion: The frequency of ADRs was high among the study cohort; however, these were managed effectively. Patients with recognized risk factors for ADRs occurrence need continuous clinical management efforts.

Frequency and Factors Associated With Adverse Events Among Multi-Drug Resistant Tuberculosis Patients in Pakistan: A Retrospective Study

Background

Treatment of multi-drug resistant tuberculosis (MDR-TB) for a prolonged period with comparatively less effective and more toxic second-line anti-TB drugs is associated with greater incidence of adverse events.

Study aim

This study aimed to evaluate the frequency and factors associated with occurrence of adverse events among patients with MDR-TB attending the Bahawal Victoria Hospital, Bahawalpur, Pakistan.

Study design

This retrospective study included all patients with MDR-TB who were registered and treated at the study site between June 2014 and December 2016 and had their treatment outcomes available at the time of data collection (i.e., November 2018).

Measures and outcomes

The Electronic Nominal Record System (ERNS) records, medical charts of patients, and laboratory reports were reviewed to obtain the data. Adverse events were reported as per the standard criteria recommended by the WHO. Multivariate binary logistic regression was used to find the independent factors associated with the occurrence of adverse events.

Results

A total of 179 patients with MDR-TB were included in the final analysis. Out of these, 114 (63.7%) patients experienced at least one adverse event during the course of their treatment. Depression was the most common adverse events (33%), followed by nausea and vomiting (27.4%) and arthralgia (27.4%). The factors associated with the occurrence of adverse events included presence of comorbidity (adjusted odds ratio [AOR] 2.951; 95% CI 1.423, 6.118) and being employed (AOR 3.445; 95% CI 1.188, 9.993).

Conclusion

Adverse events were prevalent in this cohort, however, resolved with the effective management approaches. Patients with identified factors for occurrence of adverse events need special attention and enhanced clinical management.

Incidence of adverse drug events among patients on second line anti-tuberculosis regimen in the littoral region of cameroon

Background

An adverse drug event (ADE) is an injury resulting from medical intervention associated with a drug. This study assesses the incidence of ADEs among participants on second-line drugs for tuberculosis (TB) in Cameroon.

Methods

This was a longitudinal observational study including 65 participants and carried out from January 2017 to December 2017. Markers of ADEs were obtained from creatinine, transaminase audiogram, and clinical data. Multivariate analysis was used to determine the association between predictors and ADEs.

Results

Forty-eight (73.8%) of the 65 participants developed 72 ADEs. Fifty-four (75%), 11 (15.3%), and 7 (9.7%) of the 72 ADEs were classified as Grades 1, 2, and 3, respectively. Gastrointestinal disorders were most common (35 [46.6%]) followed by auditory injuries (16 [22.2%]), hepatotoxicity (11 [15.3%]), neurological disorders (6 [8.3%]), and kidney disorders (4 [5.6%]). The follow-up duration of this study was 11,250-person day (PDY). The incidence rate for ADEs was 4.3/1000 PDY and that for gastrointestinal disorders, auditory injuries, hepatotoxicity, neurological disorders, and kidney disorders was 3.1, 1.4, 1.0, 0.5, and 0.2 (/1000PDY), respectively. Kanamycin (65 [90.3%]), isoniazid (4 [5.6%]), and ethambutol (3 [4.2%]) were incriminated with ADEs. Most (29 [60.4%]) of the ADEs occurred during the first 2 months of drug initiation. There was an association between poor treatment outcome and ADEs (P = 0.04, odds ratio = 1.20, 95% confidence of interval = 0.21-6.80].

Conclusions

The incidence of ADEs is associated with several factors and most of them occurred during the intensive phase of treatment. Kanamycin was the most associated drug linked to ADEs requiring its replacement with a less toxic one.

Modern approaches to pharmacotherapy of tuberculosis infection in children

Anti-TB drugs for children: Aetiotropic therapy is used for the treatment of tuberculosis (TB) in children, as well as in adult patients. Anti-tuberculosis drugs (anti-TB drugs) are divided into 3 lines, taking into account drug sensitivity in Mycobacterium tuberculosis (MBT). First-line anti-TB drugs (basic) are used to treat TB caused by drug-susceptible MBT. Second- and third-line (reserve) drugs are recommended for the treatment of MBT-induced multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB, respectively.

Stages and regimens to treat tuberculosis: Chemotherapy of tuberculosis in children is carried out in 2 stages (intensive treatment and continuation of treatment) and includes 5 regimens. Each regimen assumes a certain combination of anti-TB drugs, indicating the duration and frequency of their administration. The final chemotherapy regimen is chosen only according to the results of determining the drug sensitivity. To improve the TB epidemic among children, it is important to improve the regimens for the use of anti-TB drugs. The effectiveness of anti-tuberculosis pharmacotherapy is largely determined by the MBT sensitivity and the rational choice of the chemotherapy regimen. The wrong choice of a chemotherapy regimen or its violation threatens to reduce the effectiveness of pharmacotherapy and expand the spectrum of resistance of the pathogen. The development of fixed-dose combination anti-TB drugs and special dosage forms for children will improve the quality of chemotherapy and adherence to treatment. Pharmacoeconomic studies are needed to increase the effectiveness of drug pharmacotherapy for tuberculosis infection in children and to optimize the costs of its implementation.

Chemical Classes Presenting Novel Antituberculosis Agents Currently in Different Phases of Drug Development: A 2010-2020 Review

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is a curable airborne disease currently treated using a drug regimen consisting of four drugs. Global TB control has been a persistent challenge for many decades due to the emergence of drug-resistant Mtb strains. The duration and complexity of TB treatment are the main issues leading to treatment failures. Other challenges faced by currently deployed TB regimens include drug-drug interactions, miss-matched pharmacokinetics parameters of drugs in a regimen, and lack of activity against slow replicating sub-population. These challenges underpin the continuous search for novel TB drugs and treatment regimens. This review summarizes new TB drugs/drug candidates under development with emphasis on their chemical classes, biological targets, mode of resistance generation, and pharmacokinetic properties. As effective TB treatment requires a combination of drugs, the issue of drug-drug interaction is, therefore, of great concern; herein, we have compiled drug-drug interaction reports, as well as efficacy reports for drug combinations studies involving antitubercular agents in clinical development.

Unfavorable outcomes to second-line tuberculosis therapy among HIV-infected versus HIV-uninfected patients in sub-Saharan Africa: A systematic review and meta-analysis

BACKGROUND

Drug resistance is a key obstacle to the global target set to end tuberculosis by 2030. Clinical complexities in drug-resistant tuberculosis and HIV-infection co-management could worsen outcomes of second-line anti-tuberculosis drugs. A comprehensive estimate for risks of unsuccessful outcomes to second-line tuberculosis therapy in HIV-infected versus HIV-uninfected patients is mandatory to address such aspects in segments of the target set. Therefore, this meta-analysis was aimed to estimate the pooled risk ratios of unfavorable outcomes to second-line tuberculosis therapy between HIV-infected and HIV-uninfected patients in sub-Saharan Africa.

METHODS

We conducted a literature search from PubMed/MEDLINE, EMBASE, SCOPUS and Google Scholar. We screened the retrieved records by titles and abstracts. Finally, we assessed eligibility and quality of full-text articles for the records retained by employing appraisal checklist of the Joanna Briggs Institute. We analyzed the data extracted from the included studies by using Review Manager Software, version 5.3 and presented our findings in forest and funnel plots. Protocol for this study was registered on PROSPERO (ID: CRD42020160473).

RESULTS

A total of 19 studies with 1,766 from 4,481 HIV-infected and 1,164 from 3,820 HIV-uninfected patients had unfavorable outcomes. The risk ratios we estimated between HIV-infected and HIV-uninfected drug-resistant tuberculosis patients were 1.18 (95% CI: 1.07-1.30; I2 = 48%; P = 0.01) for the overall unfavorable outcome; 1.50 (95% CI: 1.30-1.74) for death; 0.66 (95% CI: 0.38-1.13) for treatment failure; and 0.82 (95% CI: 0.74-0.92) for loss from treatment. Variable increased risks of unfavorable outcomes estimated for subgroups with significance in mixed-age patients (RR: 1.22; 95% CI: 1.10-1.36) and eastern region of sub-Saharan Africa (RR: 1.47; 95% CI: 1.23-1.75).

CONCLUSIONS

We found a higher risk of unfavorable treatment outcome in drug-resistant tuberculosis patients with death highly worsening in HIV-infected than in those HIV-uninfected patients. The risks for the unfavorable outcomes were significantly higher in mixed-age patients and in the eastern region of sub-Saharan Africa. Therefore, special strategies that reduce the risks of death should be discovered and implemented for HIV and drug-resistant tuberculosis co-infected patients on second-line tuberculosis therapy with optimal integration of the two programs in the eastern region of sub-Saharan Africa.

Isoniazid-phytochemical conjugation: A new approach for potent and less toxic anti-TB drug development

Mycobacterium tuberculosis (Mtb) causes one of the most grievous pandemic infectious diseases, tuberculosis (TB), with long-term morbidity and high mortality. The emergence of drug-resistant Mtb strains, and the co-infection with human immunodeficiency virus, challenges the current WHO-TB stewardship programs. The first-line anti-TB drugs, isoniazid (INH) and rifampicin (RIF), have become extensively obsolete in TB control from chromosomal mutations during the last decades. However, based on clinical trial statistics, the production of well-tolerated anti-TB drug(s) is miserably low. Alternately, semi-synthesis or structural modifications of first-line obsolete antitubercular drugs remain as the versatile approach for getting some potential medicines. The use of any suitable phytochemicals with INH in a hybrid formulation could be an ideal approach for the development of potent anti-TB drug(s). The primary objective of this review was to highlight and analyze available INH-phytochemical hybrid research works. The utilization of phytochemicals through chemical conjugation is a new trend toward the development of safer/non-toxic anti-TB drugs.

New Drugs for the Treatment of Tuberculosis

Tuberculosis (TB) has now surpassed HIV as the leading infectious cause of death, and treatment success rates are declining. Multidrug-resistant TB, extensively drug-resistant TB, and even totally drug-resistant TB threaten to further destabilize disease control efforts. The second wave in TB drug development, which includes the diarylquinoline, bedaquiline, and the nitroimidazoles delamanid and pretomanid, may offer options for simpler, shorter, and potentially all-oral regimens to treat drug-resistant TB. The "third wave" of TB drug development includes numerous promising compounds, including less toxic versions of older drug classes and candidates with novel mechanisms of action.

Diagnosis and Management of Multidrug-Resistant Tuberculosis in Children: A Practical Approach

Approximately 25,000 children develop multidrug-resistant (MDR) tuberculosis (TB) each year, but few of them are diagnosed and appropriately treated for MDR-TB. New diagnostic tools have improved our ability to diagnose children with bacteriologically confirmed TB earlier. However, the majority of childhood TB cases are not bacteriologically confirmed; therefore a high index of suspicion is needed, and taking a detailed history of contact with drug-resistant source cases and previous TB treatment is important to identify presumed MDR-TB cases. Treatment for MDR-TB is rapidly changing with the addition of new and repurposed drugs, the introduction of shorter regimens and the move towards injectable-free, all-oral MDR-TB treatment regimens. Children have been neglected in the introduction of the new drugs, but drug dosing and safety studies are now being completed. This article presents a practical approach in deciding which regimen to use in individual children in need of MDR-TB treatment. Outcomes in those treated are generally good, but only <5% of children with MDR-TB are currently diagnosed and appropriately treated. Diagnosing children with MDR-TB and getting them on to correct treatment regimens should now be our main focus.

Inhaled Antibiotics for Mycobacterial Lung Disease

Mycobacterial lung diseases are an increasing global health concern. Tuberculosis and nontuberculous mycobacteria differ in disease severity, epidemiology, and treatment strategies, but there are also a number of similarities. Pathophysiology and disease progression appear to be relatively similar between these two clinical diagnoses, and as a result these difficult to treat pulmonary infections often require similarly extensive treatment durations of multiple systemic drugs. In an effort to improve treatment outcomes for all mycobacterial lung diseases, a significant body of research has investigated the use of inhaled antibiotics. This review discusses previous research into inhaled development programs, as well as ongoing research of inhaled therapies for both nontuberculous mycobacterial lung disease, and tuberculosis. Due to the similarities between the causative agents, this review will also discuss the potential cross-fertilization of development programs between these similar-yet-different diseases. Finally, we will discuss some of the perceived difficulties in developing a clinically utilized inhaled antibiotic for mycobacterial diseases, and potential arguments in favor of the approach.

Is hypothyroidism rare in multidrug resistance tuberculosis patients on treatment? A systematic review and meta-analysis

BACKGROUND

Hypothyroidism is one of the adverse drug reactions that associated with Multidrug Resistant Tuberculosis (MDR-TB) medications. Extremely variable magnitude of hypothyroidism in MDR-TB patients has been reported from different parts of the world. However, there is no evidence that tried to estimate the pooled prevalence of hypothyroidism to confirm the rareness of hypothyroidism in MDR-TB patients on treatment. Therefore, we did a systematic review and meta-analysis to estimate the prevalence of hypothyroidism in MDR-TB patients on treatment, and to summarize the demographic and clinical characteristics of the patients.

METHODS

We conducted a systematic review and meta-analysis on studies reported around the world on the prevalence of hypothyroidism in MDR-TB patients on treatment. We searched electronic databases: PubMed/Medline, EMBASE, CINAHL, Science Direct, Academic Search Complete and Google scholar for English language articles without limiting publication year. We also reviewed the bibliographies of relevant studies and conducted an electronic search for relevant conference abstracts. Eligible studies were cross-sectional and cohort studies that included at least five participants. We used a random-effects model to estimate the pooled prevalence of hypothyroidism. The registration number of this review study protocol is CRD42018109237.

RESULTS

We included 30 studies and pooled data on a total of 6,241 MDR-TB patients. The crude prevalence of hypothyroidism was extremely heterogeneous. The pooled prevalence of hypothyroidism in MDR-TB patients on treatment was 17.0% (95% CI: 13.0-20.0). Ethionamide and para-aminosalicylic acid (PAS) were the most frequently reported drugs that associated with the occurrence of hypothyroidism.

CONCLUSION

This review revealed that hypothyroidism is not a rare adverse drug reaction in MDR-TB patients on treatment. Ethionamide and PAS were the most frequently reported drugs that associated with the occurrence of hypothyroidism. Screening of hypothyroidism in MDR-TB patients on treatment is important while targeting patients on Ethionamide and PAS based treatment regimen.

Incidence and predictors of major adverse drug events among drug-resistant tuberculosis patients on second-line anti-tuberculosis treatment in Amhara regional state public hospitals; Ethiopia: a retrospective cohort study

Background

Second line anti-tuberculosis drugs are substantially complex, long term, more costly, and more toxic than first line anti-tuberculosis drugs. In Ethiopia, evidence on the incidence and predictors of adverse drug events has been limited. Thus, this study aimed at assessing incidence and predictors of major adverse drug events among drug resistant tuberculosis patients on second line tuberculosis treatment in Amhara Regional State public hospitals, Ethiopia.

Methods

A multi-center retrospective cohort study was conducted on 570 drug resistant tuberculosis Patients. Data were entered in to EPI-Data version 4.2.0.0 and exported to Stata version 14 for analysis. Proportional hazard assumption was checked. The univariate Weibull regression gamma frailty model was fitted. Cox-Snell residual was used to test goodness of fit and Akaike Information Criteria (AIC) for model selection. Hazard ratio with 95% CI was computed and variables with P-value < 0.05 in the multivariable analysis were taken as significant predictors for adverse drug event.

Results

A total of 570 patients were followed for 5045.09 person-month (PM) observation with a median follow-uptime of 8.23 months (Inter Quartile Range (IQR) =2.66–23.33). The overall incidence rate of major adverse drug events was 5.79 per 100 PM (95% CI: 5.16, 6.49). Incidence rate at the end of 2nd, 4th, and 6th months was 13.73, 9.25, 5.97 events per 100 PM observations, respectively. Age at 25–49 (Adjusted Hazard Ratio (AHR) = 3.36, 95% CI: 1.36, 8.28), and above 50 years (AHR = 5.60, 95% CI: 1.65, 19.05), co-morbid conditions (AHR = 2.74 CI: 1.12, 6.68), and anemia (AHR = 3.25 CI: 1.40, 7.53) were significant predictors of major adverse drug events.

Conclusion

The incidence rate of major adverse drug events in the early 6 months of treatment was higher than that of the subsequent months. Age above 25 years, base line anemia, and co-morbid conditions were independent predictors of adverse drug events. Thus, addressing significant predictors and strengthening continuous follow-ups are highly recommended in the study setting.

Effect of Coadministration of Lidocaine on the Pain and Pharmacokinetics of Intramuscular Amikacin in Children With Multidrug-Resistant Tuberculosis: A Randomized Crossover Trial

BACKGROUND

Currently recommended treatment for multidrug-resistant (MDR) tuberculosis (TB) includes 4-8 months of an injectable medication, which is poorly tolerated. We evaluated the impact of coadministering lidocaine on pain and pharmacokinetics of intramuscular injections of amikacin in children with MDR-TB.

METHODS

Children 8-18 years of age, receiving amikacin for MDR-TB treatment in Cape Town, South Africa, were eligible for this randomized crossover trial. Participants received a 15 mg/kg dose of intramuscular amikacin with and without additional lidocaine (0.2-0.4 mg/kg) on different days and were randomized to the order of the treatments (the sequence). Participants and staff completing evaluations were blinded to sequence. Samples were drawn predose, and at 1, 2, 4, 6 and 8 hours postdose for measurement of plasma amikacin concentrations. Pain was assessed by participants using the Wong Baker FACES pain scale (0-5) predose, immediately after the injection and then at 30 and 60 minutes. Pharmacokinetic measures were calculated using noncompartmental analysis.

RESULTS

Twelve children were included, median age 11.5 years (interquartile range [IQR], 9.9-13.4 years). Participant-reported pain scores immediately after the amikacin injection were lower when lidocaine was coadministered: 1.0 (IQR, 0.5-2.0) with lidocaine versus 2.5 (1.0-4.0) without lidocaine (P = 0.004). The median area under the concentration time curve0-8 and median maximum plasma concentration of amikacin were 109.0 μg × h/mL (IQR, 84.7-121.3) and 36.7 μg/mL (IQR, 34.1-40.5) with lidocaine compared with 103.3 μg × h/mL (IQR, 81.7-135.0; P = 0.814) and 34.1 μg/mL (IQR, 35.6-46.4; P = 0.638) without lidocaine, respectively.

CONCLUSIONS

The coadministration of lidocaine resulted in reduced pain immediately after the injection and did not alter amikacin area under the concentration time curve or maximum plasma concentration.

Epidemiology of Pediatric Multidrug-Resistant Tuberculosis in the United States, 1993-2014

Background

Multidrug-resistant tuberculosis (MDR-TB) is an important global public health threat, but accurate estimates of MDR-TB burden among children are lacking.

Methods

We analyzed demographic, clinical, and laboratory data for newly diagnosed pediatric (age <15 years) TB cases reported to the US National TB Surveillance System during 1993-2014. MDR-TB was defined as culture-confirmed TB disease with resistance to at least isoniazid and rifampicin. To ascertain potential underestimation of pediatric MDR-TB, we surveyed high-burden states for clinically diagnosed cases treated for MDR-TB.

Results

Of 20789 pediatric TB cases, 5162 (24.8%) had bacteriologically confirmed TB. Among 4826 (93.5%) with drug susceptibility testing, 82 (1.7%) had MDR-TB. Most pediatric MDR-TB cases were female (n = 51 [62%]), median age was 5 years (interquartile range, 1-12 years), one-third were Hispanic (n = 28 [34%]), and two-thirds (n = 55 [67%]) were born in the United States. Most cases had additional resistance to ≥1 other first-line drug (n = 66 [81%]) and one-third had resistance to ≥1 second-line drug (24/73 tested). Of 77 who started treatment prior to 2013, 66 (86%) completed treatment and 4 (5%) died. Among the 4 high-TB-burden states/jurisdictions surveyed, there was 42%-55% underestimation of pediatric MDR-TB cases when using only culture-confirmed case definitions.

Conclusions

Only one-quarter of pediatric TB cases had culture-confirmed TB, likely resulting in underestimation of true pediatric MDR-TB burden in the United States using strictly bacteriologic criteria. Better estimates of pediatric MDR-TB burden in the United States are needed and should include clinical diagnoses based on epidemiologic criteria.

Update on trends in childhood tuberculosis

PURPOSE OF REVIEW

Although tuberculosis (TB) causes much morbidity and mortality in children, diagnosis and treatment remain challenging. Recently, children have gained increasing attention in research and clinical trials driving improved contact management, case identification and treatment of both drug-susceptible and drug-resistant TB. This review highlights some recent advances.

RECENT FINDINGS

The tuberculin skin test is the most widely used test to distinguish Mycobacterium tuberculosis (M. tuberculosis) infection from active TB, however, using M. tuberculosis-specific, antigenic stimulation of CD4 and CD8 cells appear more effective. The use of Xpert MTB/RIF to identify M. tuberculosis in clinical samples, together with novel sampling methods have in part, overcome the difficulty of sampling and increased case identification capacity. Advances in treating both drug-susceptible and drug-resistant childhood TB show promise in being more paediatric friendly and improving adherence. Dosing strategies for drug-sensitive TB have improved with dispersible fixed drug combinations now available. In the treatment and prevention of drug-resistant TB, however, research involving the use of newer and more effective drugs currently recommended for adults, are still ongoing in children.

SUMMARY

The World Health Organization aims to end the TB epidemic by 2035 whereas the United Nations' Sustainable Developmental Goals sets this ambitious target for 2030. Therefore, adequate funding and implementing effective national TB programs must be prioritized, particularly in high-burden, low-income settings.

Current therapies for the treatment of multidrug-resistant tuberculosis in children in India

INTRODUCTION

Multidrug-resistant tuberculosis (MDR-TB) is a serious life threatening condition affecting children as well as adults worldwide. Timely diagnosis and effective treatment, both of which are complex in children, are the prerogatives for a favorable outcome. Areas covered: This review covers epidemiology, treatment regimen and duration, newer drugs and adverse events in children with MDR-TB. Special note has been made of epidemiology and principles of treatment followed in Indian children. Expert opinion: High index of suspicion is essential for diagnosing childhood MDR-TB. If there is high probability, a child can be diagnosed as presumptive MDR-TB and started on empiric treatment in consultation with experts. However, every effort should be made to confirm the diagnosis. Backbone of an effective MDR-TB regimen consists of four 2nd line anti-TB drugs plus pyrazinamide; duration being 18-24 months. The newer drugs delamanid and bedaquiline can be used in younger children if no other alternatives are available after consultation with experts. Wider availability of these drugs should be ensured for benefit to all concerned. More research is required for development of new and repurposed drugs to combat MDR-TB. Children need to be included in clinical trials for such life-saving drugs, so that nobody is denied the benefits.

Clinical management of adults and children with multidrug-resistant and extensively drug-resistant tuberculosis

BACKGROUND

Globally there is a burgeoning epidemic of drug monoresistant tuberculosis (TB), multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Almost 20% of all TB strains worldwide are resistant to at least one major TB drug, including isoniazid. In several parts of the world there is an increasing incidence of MDR-TB, and alarmingly, almost a third of MDR-TB cases globally are resistant to either a fluoroquinolone or aminoglycoside. This trend cannot be ignored because drug-resistant TB is associated with greater morbidity compared to drug-susceptible TB, accounts for almost 25% of global TB mortality, is extremely costly to treat, consumes substantial portions of budgets allocated to national TB programmes in TB-endemic countries and is a major threat to healthcare workers, who are already in short supply in resource-poor settings. Even more worrying is the growing epidemic of resistance beyond XDR-TB, including resistance to newer drugs such as bedaquiline and delamanid, as well as the increasing prevalence of programmatically incurable TB in countries like South Africa, Russia, India and China. These developments threaten to reverse the gains already made against TB.

SOURCES

Articles related to MDR-TB and XDR-TB found on PubMed in all languages up to September 2016, published reviews, and files of the authors.

AIM AND CONTENT

To review the clinical management of adults and children with MDR- and XDR-TB with a particular emphasis on the utility of newer and repurposed drugs such as linezolid, bedaquiline and delamanid, as well as management of MDR- and XDR-TB in special situations such as in HIV-infected persons and in children.

IMPLICATIONS

This review informs on the prevention, diagnosis, and clinical management of MDR-TB and XDR-TB.