A Mathematical Model for the Impact of 3HP and Social Programme Implementation on the Incidence and Mortality of Tuberculosis: Study in Brazil.

In this paper, we presented a mathematical model for tuberculosis with treatment for latent tuberculosis cases and incorporated social implementations based on the impact they will have on tuberculosis incidence, cure, and recovery. We incorporated two variables containing the accumulated deaths and active cases into the model in order to study the incidence and mortality rate per year with the data reported by the model. Our objective is to study the impact of social program implementations and therapies on latent tuberculosis in particular the use of once-weekly isoniazid-rifapentine for 12 weeks (3HP). The computational experimentation was performed with data from Brazil and for model calibration, we used the Markov Chain Monte Carlo method (MCMC) with a Bayesian approach. We studied the effect of increasing the coverage of social programs, the Bolsa Familia Programme (BFP) and the Family Health Strategy (FHS) and the implementation of the 3HP as a substitution therapy for two rates of diagnosis and treatment of latent at 1% and 5%. Based of the data obtained by the model in the period 2023-2035, the FHS reported better results than BFP in the case of social implementations and 3HP with a higher rate of diagnosis and treatment of latent in the reduction of incidence and mortality rate and in cases and deaths avoided. With the objective of linking the social and biomedical implementations, we constructed two different scenarios with the rate of diagnosis and treatment. We verified with results reported by the model that with the social implementations studied and the 3HP with the highest rate of diagnosis and treatment of latent, the best results were obtained in comparison with the other independent and joint implementations. A reduction of the incidence by 36.54% with respect to the model with the current strategies and coverage was achieved, and a greater number of cases and deaths from tuberculosis was avoided.

Determining the Delamanid Pharmacokinetics/Pharmacodynamics Susceptibility Breakpoint Using Monte Carlo Experiments.

Antimicrobial susceptibility testing, based on clinical breakpoints that incorporate pharmacokinetics/pharmacodynamics (PK/PD) and clinical outcomes, is becoming a new standard in guiding individual patient therapy as well as for drug resistance surveillance. However, for most antituberculosis drugs, breakpoints are instead defined by the epidemiological cutoff values of the MIC of phenotypically wild-type strains irrespective of PK/PD or dose. In this study, we determined the PK/PD breakpoint for delamanid by estimating the probability of target attainment for the approved dose administered at 100 mg twice daily using Monte Carlo experiments. We used the PK/PD targets (0- to 24-h area under the concentration-time curve to MIC) identified in a murine chronic tuberculosis model, hollow fiber system model of tuberculosis, early bactericidal activity studies of patients with drug-susceptible tuberculosis, and population pharmacokinetics in patients with tuberculosis. At the MIC of 0.016 mg/L, determined using Middlebrook 7H11 agar, the probability of target attainment was 100% in the 10,000 simulated subjects. The probability of target attainment fell to 25%, 40%, and 68% for PK/PD targets derived from the mouse model, the hollow fiber system model of tuberculosis, and patients, respectively, at the MIC of 0.031 mg/L. This indicates that an MIC of 0.016 mg/L is the delamanid PK/PD breakpoint for delamanid at 100 mg twice daily. Our study demonstrated that it is feasible to use PK/PD approaches to define a breakpoint for an antituberculosis drug.

Serious adverse drug reactions in sub-Saharan Africa in the era of antiretroviral treatment: A systematic review.

We aimed to summarize and describe the burden of serious adverse drug reactions (ADRs) in sub-Saharan Africa (SSA) in the era of antiretroviral therapy. We searched Medline, CINAHL, Africa-Wide Information, Scopus, and Web of Science, without language restriction up to March 2021. We hand-searched reference lists, conference abstracts, and dissertation databases. We included studies reporting proportions of admissions attributed to ADRs, admissions prolonged by ADRs, or in-hospital deaths attributed to ADRs. Two reviewers independently screened the studies, reviewed the study quality using a previously published tool, and extracted the data. We tested for heterogeneity using I2 -statistics and summarized the study results using medians and interquartile ranges. Subgroup analyses summarized the results by study quality, setting, methodology, and population. From 1005 unique references identified, we included 15 studies. Median study quality was 7/10; heterogeneity was very high. Median [IQR] proportion of admissions attributed to ADRs was 4.8% [1.5% to 7.0%] (14 studies) and 6.4% [4.0% to 8.4%] in nine active surveillance studies in adults. Two pediatric studies reported the proportion of admissions prolonged by ADRs (0.29% and 0.99%). Three studies reported the proportion of in-hospital deaths attributed to ADRs (2.5%, 13%, and 16%). Antiretroviral and antituberculosis drugs were often implicated in serious ADRs. Evidence of the burden of serious ADRs in SSA is patchy and heterogeneous. A few high-quality studies suggest that the burden is considerable, and that it reflects the regional impact of the HIV pandemic. Further characterization of this burden is required, ideally in studies of standardized methodology.

Population pharmacokinetics of oral levofloxacin in healthy volunteers and dosing optimization for multidrug-resistant tuberculosis therapy.

Levofloxacin is considered a key component of a multidrug-resistant tuberculosis (MDR-TB) regimen. However, there is considerable concern regarding the subtherapeutic concentrations of the currently used doses and the development of drug resistance. Therefore, this study aimed to describe the population pharmacokinetics (PPK) of oral levofloxacin in healthy volunteers and to evaluate the probability of target attainment (PTA) in an attempt to optimize the dosing regimens for MDR-TB therapy. Data of levofloxacin in healthy volunteers from a previous study were used to construct a PPK model. Monte Carlo simulations were performed to derive the PTAs of various regimens. A two-compartment model with linear elimination and transit absorption compartments best described the pharmacokinetics (PK) of levofloxacin. The estimated PK parameters (interindividual variability, %) were: apparent clearance 8.32 L h-1 (22.6%), apparent central volume of distribution 35.8 L (45.2%), apparent peripheral volume of distribution 39.7 L, intercompartmental clearance 40.6 L h-1 (43.8%), absorption rate constant 7.45 h-1 (150%), mean absorption transit time 0.355 h (52.4%), and total number of transit compartments 6.01 (131.9%). Monte Carlo simulations using levofloxacin 750-1000 mg yielded a probability of achieving a target free area under the concentration-time curve/minimum inhibitory concentration (MIC) of 100 at greater than 90% for Mycobacterium tuberculosis with an MIC < 0.5 mg L-1 , while a dose of 1500 mg was required for strains with an MIC of 1 mg L-1 . A higher dose of levofloxacin might be needed to treat tuberculosis. However, further studies on the efficacy and safety of this dose are needed to confirm our findings.

A systematic review of pharmacoeconomic evaluations on oral diarylquinoline-based treatment for drug-resistant tuberculosis: from high to low burden countries.

Introduction: There is a rising global interest in the pharmacoeconomic evaluations of bedaquiline (BDQ), a novel oral diarylquinoline, for treatment of drug-resistant tuberculosis (DR-TB).Areas covered: This article systematically reviewed publications retrieved from Medline, American Psychological Association-Psychology information, Web of Science, Embase, Scopus, Science direct, Center for Reviews and Dissemination, and CINAHL Complete during 2010-2020 on pharmacoeconomic studies on BDQ for DR-TB treatment. Ten Markov model-based cost-effectiveness analyses identified were conducted in high (n = 4), intermediate (n = 2), and low (n = 4) TB burden countries.Expert opinion: The paucity of model-based health economic analyses on BDQ-containing regimens for DR-TB indicated that further pharmacoeconomic research of BDQ-based regimens, on the aspects of duration of BDQ treatment, types of DR-TB indicated, and settings of regions and health-systems, is highly warranted to inform global cost-effective use of BDQ-based regimens for DR-TB treatment.

Toxicity studies of highly bioavailable isoniazid loaded solid lipid nanoparticles as per Organisation for Economic Co-operation and Development (OECD) guidelines.

Solid lipid nanoparticles (SLNs) are presently being promoted to improve bioavailability of encapsulated drugs. These are well tolerated in living systems, as they are made from biocompatible material. Despite finding extensive applicability, these systems have not been sufficiently investigated for the toxicity so far. We have reported use of SLNs to improve plasma bioavailability of isoniazid (INH), a hepatotoxic, antitubercular drug. Presently we evaluate acute and repeated (28-day) oral dose toxicity, with satellite group, of developed INH loaded COMBI-SLN. In addition to high bioavailability, the COMBI-SLN exhibited 3 times higher LD50 (2000 mg/kg BW) versus 650 mg/kg BW for free INH. Results were complemented with histopathological evidence in brain, sciatic nerve and liver tissue all of which indicated enhanced safety of INH upon incorporation into SLNs. In the repeated dose study at doses selected as per Organisation for Economic Co-operation and Development (OECD) guidelines, a series of behavioural and haematological tests, clinical biochemistry (kidney and liver function, lipid profile) and histopathological studies were performed to evaluate the effect of low (250 mg/kg BW), medium (500 mg/kg BW) and high oral dose (1000 mg/kg BW). Absence of adverse effects like hepatotoxicity and peripheral neuropathy observed in rats at an oral intake level of 500 and 1000 mg/kg BW of COMBI-SLN, that is 20-40 folds above the anticipated human intake levels (after normalizing the surface area correction for rats), supports the conclusion that SLN are an intrinsically safe nanocarrier system that improves both the efficacy and the safety of INH.

Risk of developing active tuberculosis following tuberculosis screening and preventive therapy for Tibetan refugee children and adolescents in India: An impact assessment.

BACKGROUND: Tuberculosis (TB) rates among Tibetan refugee children and adolescents attending boarding schools in India are extremely high. We undertook a comprehensive case finding and TB preventive treatment (TPT) program in 7 schools in the Zero TB Kids project. We aimed to measure the TB infection and disease burden and investigate the risk of TB disease in children and adults who did and did not receive TPT in the schools. METHODS AND FINDINGS: A mobile team annually screened children and staff for TB at the 7 boarding schools in Himachal Pradesh, India, using symptom criteria, radiography, molecular diagnostics, and tuberculin skin tests. TB infection (TBI) was treated with short-course regimens of isoniazid and rifampin or rifampin. TB disease was treated according to Tibetan and Indian guidelines. Between April 2017 and December 2019, 6,582 schoolchildren (median age 14 [IQR 11-16] years) and 807 staff (median age 40 [IQR 33-48] years) were enrolled. Fifty-one percent of the students and 58% of the staff were females. Over 13,161 person-years of follow-up in schoolchildren (median follow-up 2.3 years) and 1,800 person-years of follow-up in staff (median follow-up 2.5 years), 69 TB episodes occurred in schoolchildren and 4 TB episodes occurred in staff, yielding annual incidence rates of 524/100,000 (95% CI 414-663/100,000) person-years and 256/100,000 (95% CI 96-683/100,000) person-years, respectively. Of 1,412 schoolchildren diagnosed with TBI, 1,192 received TPT. Schoolchildren who received TPT had 79% lower risk of TB disease (adjusted hazard ratio [aHR] 0.21; 95% CI 0.07-0.69; p = 0.010) compared to non-recipients, the primary study outcome. Protection was greater in recent contacts (aHR 0.07; 95% CI 0.01-0.42; p = 0.004), the secondary study outcome. The prevalence of recent contacts was 28% (1,843/6,582). Two different TPT regimens were used (3HR and 4R), and both were apparently effective. No staff receiving TPT developed TB. Overall, between 2017 and 2019, TB disease incidence decreased by 87%, from 837/100,000 (95% CI 604-1,129/100,000) person-years to 110/100,000 (95% CI 36-255/100,000) person-years (p < 0.001), and TBI prevalence decreased by 42% from 19% (95% CI 18%-20%) to 11% (95% CI 10%-12%) (p < 0.001). A limitation of our study is that TB incidence could be influenced by secular trends during the study period. CONCLUSIONS: In this study, following implementation of a school-wide TB screening and preventive treatment program, we observed a significant reduction in the burden of TB disease and TBI in children and adolescents. The benefit of TPT was particularly marked for recent TB contacts. This initiative may serve as a model for TB detection and prevention in children and adolescents in other communities affected by TB.

Dual antitubercular drug loaded liposomes for macrophage targeting: development, characterisation, ex vivo and in vivo assessment.

AIM: The present study was conducted to formulate and investigate liposomes for the dual drug delivery based on anti-tubercular drug(s) combination i.e. Isoniazid (INH) and Rifampicin (RIF). MATERIALS AND METHODS: Mannosylated and non mannosylated liposomes were prepared by lipid thin film hydration method, using DSPC: Chol at a molar ratio 6:4 while in case of mannosylated liposomes DSPC: Chol: Man-C4-Chol at a molar ratio 6.0:3.5:0.5 were used and extensively characterised. The particle size and zeta potential were recorded to be 1.29 ± 0.24 µm and -9.1 ± 0.11 mV. The drug entrapment (%) was recorded to be 84.7 ± 1.25% for Rifampicin and 31.8 ± 0.12% for Isoniazid. RESULTS: The antitubercular activity studied in Balb/C mice was maximum in the case of mannosylated liposomes. The biodistribution studies also revealed higher drug(s) concentration (accumulation) maintained over a protracted period. CONCLUSIONS: The liposomal preparations are passively as well as actively uptaken by the alveolar macrophages which are the cellular tropics of infection. The mannosylated liposomes appear to be a potential carrier for dual drug delivery and targeted antitubercular therapy.

Cost-effectiveness of one month of daily isoniazid and rifapentine versus three months of weekly isoniazid and rifapentine for prevention of tuberculosis among people receiving antiretroviral therapy in Uganda.

INTRODUCTION: Preventive therapy is essential for reducing tuberculosis (TB) burden among people living with HIV (PLWH) in high-burden settings. Short-course preventive therapy regimens, such as three-month weekly rifapentine and isoniazid (3HP) and one-month daily rifapentine and isoniazid (1HP), may help facilitate uptake of preventive therapy for latently infected patients, but the comparative cost-effectiveness of these regimens under different conditions is uncertain. METHODS: We used a Markov state-transition model to estimate the incremental costs and effectiveness of 1HP versus 3HP in a simulated cohort of patients attending an HIV clinic in Uganda, as an example of a low-income, high-burden setting in which TB preventive therapy might be prescribed to PLWH. Our primary outcome was the incremental cost-effectiveness ratio, expressed as 2019 US dollars per disability-adjusted life year (DALY) averted. We estimated cost-effectiveness under different conditions of treatment completion and efficacy of 1HP versus 3HP, latent TB prevalence and rifapentine price. RESULTS: Assuming equivalent clinical outcomes using 1HP and 3HP and a rifapentine price of $0.21 per 150 mg, 1HP would cost an additional $4.66 per patient treated. Assuming equivalent efficacy but 20% higher completion with 1HP versus 3HP, 1HP would cost $1,221 per DALY averted relative to 3HP. This could be reduced to $18 per DALY averted if 1HP had 5% greater efficacy than 3HP and the price of rifapentine were 50% lower. At a rifapentine price of $0.06 per 150 mg, 1HP would become cost-neutral relative to 3HP. CONCLUSIONS: 1HP has the potential to be cost-effective under many realistic circumstances. Cost-effectiveness depends on rifapentine price, relative completion and efficacy, prevalence of latent TB and local willingness-to-pay.

Cost of Tuberculosis Therapy Directly Observed on Video for Health Departments and Patients in New York City; San Francisco, California; and Rhode Island (2017-2018).

Objectives. To assess costs of video and traditional in-person directly observed therapy (DOT) for tuberculosis (TB) treatment to health departments and patients in New York City, Rhode Island, and San Francisco, California.Methods. We collected health department costs for video DOT (VDOT; live and recorded), and in-person DOT (field- and clinic-based). Time-motion surveys estimated provider time and cost. A separate survey collected patient costs. We used a regression model to estimate cost by DOT type.Results. Between August 2017 and June 2018, 343 DOT sessions were captured from 225 patients; 87 completed a survey. Patient costs were lowest for VDOT live ($1.01) and highest for clinic DOT ($34.53). The societal (health department + patient) costs of VDOT live and recorded ($6.65 and $12.64, respectively) were less than field and clinic DOT ($21.40 and $46.11, respectively). VDOT recorded health department cost was not statistically different from field DOT cost in Rhode Island.Conclusions. Among the 4 different modalities, both types of VDOT were associated with lower societal costs when compared with traditional forms of DOT.Public Health Implications. VDOT was associated with lower costs from the societal perspective and may reduce public health costs when TB incidence is high.

Outcomes and adverse events of pre- and extensively drug-resistant tuberculosis patients in Kinshasa, Democratique Republic of the Congo: A retrospective cohort study.

BACKGROUND: Extensively drug-resistant tuberculosis (XDR TB) is a very serious form of tuberculosis that is burdened with a heavy mortality toll, especially before the advent of new TB drugs. The Democratic Republic of the Congo (DRC) is among the countries most affected by this new epidemic. METHODS: A retrospective analysis was performed of the records of all patients with pre- and extensively drug-resistant tuberculosis hospitalized from January 1, 2015 to December 31, 2017 and monitored for at least 6 months to one year after the end of their treatment in Kinshasa; an individualized therapeutic regimen with bedaquiline for 20 months was built for each patient. The adverse effects were systematically monitored. RESULTS: Of the 40 laboratory-confirmed patients, 32 (80%) patients started treatment, including 29 preXRB and 3 XDR TB patients. In the eligible group, 3 patients (9.4%) had HIV-TB coinfections. The therapeutic success rate was 53.2%, and the mortality rate was 46.8% (15/32); there were no relapses, failures or losses to follow-up. All coinfected HIV-TB patients died during treatment. The cumulative patient survival rate was 62.5% at 3 months, 53.1% at 6 months and 53.1% at 20 months. The most common adverse events were vomiting, Skin rash, anemia and peripheral neuropathy. CONCLUSION: The new anti-tuberculosis drugs are a real hope for the management of Drug Resistant tuberculosis patient and other new therapeutic combinations may improve favorable outcomes.

Shorter antibiotic regimens impact the control efforts in high tuberculosis burden regions of Taiwan.

OBJECTIVES: To assess the potential epidemiological impact and cost-effectiveness of shorter antibiotic regimens in high tuberculosis (TB) burden regions of Taiwan. METHODS: This study combined the TB population dynamic model and cost-effectiveness analysis with local data to simulate the disease burdens, effectiveness and costs of hypothetical 4-month, 2-month and 7-day regimens compared with the standard regimen. RESULTS: The main outcomes were the potential of shorter regimens for averted incidence, mortality and disability-adjusted life years, incremental cost-effectiveness ratio and net monetary benefit. Shorter regimens would lower incidence rates and mortality cases in a high TB burden region by an average of 19-33% and 27-41%, respectively, with the potential for cost-effectiveness or cost-saving. The 2-month and 7-day regimens would be more cost-effective than the 4-month regimen. The threshold daily drug prices for achieving cost-effectiveness and cost-saving for 4-month, 2-month and 7-day regimens were $US1, $US2 and $US70, respectively. Such cost-effectiveness would remain, even if the willingness-to-pay threshold was less than one gross domestic product per capita. CONCLUSIONS: The findings support the inclusion of shorter regimens in global guidelines and regional-scale TB control strategies, which would improve disease control, particularly in settings with high rates of incidence and poor treatment outcomes.

Electronic pillbox-enabled self-administered therapy versus standard directly observed therapy for tuberculosis medication adherence and treatment outcomes in Ethiopia (SELFTB): protocol for a multicenter randomized controlled trial.

BACKGROUND: To address the multifaceted challenges associated with tuberculosis (TB) in-person directly observed therapy (DOT), the World Health Organization recently recommended that countries maximize the use of digital adherence technologies. Sub-Saharan Africa needs to investigate the effectiveness of such technologies in local contexts and proactively contribute to global decisions around patient-centered TB care. This study aims to evaluate the effectiveness of pillbox-enabled self-administered therapy (SAT) compared to standard DOT on adherence to TB medication and treatment outcomes in Ethiopia. It also aims to assess the usability, acceptability, and cost-effectiveness of the intervention from the patient and provider perspectives. METHODS: This is a multicenter, randomized, controlled, open-label, superiority, effectiveness-implementation hybrid, mixed-methods, two-arm trial. The study is designed to enroll 144 outpatients with new or previously treated, bacteriologically confirmed, drug-sensitive pulmonary TB who are eligible to start the standard 6-month first-line anti-TB regimen. Participants in the intervention arm (n = 72) will receive 15 days of HRZE-isoniazid, rifampicin, pyrazinamide, and ethambutol-fixed-dose combination therapy in the evriMED500 medication event reminder monitor device for self-administration. When returned, providers will count any remaining tablets in the device, download the pill-taking data, and refill based on preset criteria. Participants can consult the provider in cases of illness or adverse events outside of scheduled visits. Providers will handle participants in the control arm (n = 72) according to the standard in-person DOT. Both arms will be followed up throughout the 2-month intensive phase. The primary outcomes will be medication adherence and sputum conversion. Adherence to medication will be calculated as the proportion of patients who missed doses in the intervention (pill count) versus DOT (direct observation) arms, confirmed further by IsoScreen urine isoniazid test and a self-report of adherence on eight-item Morisky Medication Adherence Scale. Sputum conversion is defined as the proportion of patients with smear conversion following the intensive phase in intervention versus DOT arms, confirmed further by pre-post intensive phase BACTEC MGIT TB liquid culture. Pre-post treatment MGIT drug susceptibility testing will determine whether resistance to anti-TB drugs could have impacted culture conversion. Secondary outcomes will include other clinical outcomes (treatment not completed, death, or loss to follow-up), cost-effectiveness-individual and societal costs with quality-adjusted life years-and acceptability and usability of the intervention by patients and providers. DISCUSSION: This study will be the first in Ethiopia, and of the first three in sub-Saharan Africa, to determine whether electronic pillbox-enabled SAT improves adherence to TB medication and treatment outcomes, all without affecting the inherent dignity and economic wellbeing of patients with TB. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04216420. Registered on 2 January 2020.

The cost-effectiveness of a bedaquiline-containing short-course regimen for the treatment of multidrug-resistant tuberculosis in South Africa.

Background: Bedaquiline-containing regimens have demonstrated improved outcomes over injectable-containing regimens in the long-term treatment of multidrug-resistant tuberculosis (MDR-TB). Recently, the World Health Organization (WHO) recommended replacing injectables in the standard short-course regimen (SCR) with a bedaquiline-containing regimen. The South African national TB program similarly recommends a bedaquiline-containing regimen. Here, we investigated the cost-effectiveness of a bedaquiline-containing SCR versus an injectable-containing SCR for the treatment of MDR-TB in South Africa.Methods: A Markov model was adapted to simulate the incidence of active patients with MDR-TB. Patients could transition through eight health states: active MDR-TB, culture conversion, cure, follow-up loss, secondary MDR-TB, extensively DR-TB, end-of-life care, and death. A 5% discount was assumed on costs and outcomes. Health outcomes were expressed as disability-adjusted life years (DALYs).Results: Over a 10-year time horizon, a bedaquiline-containing SCR dominated an injectable-containing SCR, with an incremental saving of US $982 per DALY averted. A bedaquiline-containing SCR was associated with lower total costs versus an injectable-containing SCR (US $597 versus $657 million), of which US $3.2 versus $21.9 million was attributed to adverse event management.Conclusions: Replacing an injectable-containing SCR with a bedaquiline-containing SCR is cost-effective, offering a cost-saving alternative with improved patient outcomes for MDR-TB.

Model-Based Assessment of Variability in Isoniazid Pharmacokinetics and Metabolism in Patients Co-Infected With Tuberculosis and HIV: Implications for a Novel Dosing Strategy.

Tuberculosis is the most common cause of death in HIV-infected patients. Isoniazid is used as a first-line drug to treat tuberculosis infection. However, variability in isoniazid pharmacokinetics can result in hepatotoxicity or treatment failure. Determination of clinical factors affecting isoniazid pharmacokinetics and metabolic pathways in HIV co-infected patients is therefore critical. Plasma levels of isoniazid, acetyl-isoniazid, and isonicotinic acid from 63 patients co-infected with tuberculosis and HIV were analyzed by liquid chromatography with tandem mass spectrometry followed by nonlinear mixed-effects modeling. Patients were genotyped to determine acetylator status. Patients were either on concomitant efavirenz-based antiretroviral therapy or HIV treatment naïve. Clearances of isoniazid were 1.3-fold and 2.3-fold higher in intermediate and rapid acetylators, respectively, compared with slow acetylators. Patients on concomitant efavirenz-based antiretroviral therapy had 64% and 80% higher population predicted clearances of acetyl-isoniazid and isonicotinic acid, respectively, compared with patients who were HIV treatment naïve. Both sex and CD4 cell count affected the bioavailability of isoniazid. Variability in isoniazid exposure could be reduced by dose adaptions based on acetylator type and sex in addition to the currently used weight bands. A novel dosing strategy that has the potential to reduce isoniazid-related toxicity and treatment failure is presented.

Genetic Diversity in Drug Transporters: Impact in African Populations.

Polymorphisms in drug transporters, like the adenosine triposphate-binding cassette (ABC) and solute carrier (SLC) superfamilies, may contribute to the observed diversity in drug response in African patients. This review aims to provide a comprehensive summary and analysis of the frequencies and distributions in African populations of ABC and SLC variants that affect drug pharmacokinetics (PK) and pharmacodynamics (PD). Of polymorphisms evaluated in African populations, SLCO1B1 rs4149056 and SLC22A6 rs1158626 were found at markedly higher frequencies than in non-African populations. SLCO1B1 rs4149056 was associated with reduction in rifampin exposure, which has implications for dosing this important anti-tuberculosis therapy. SLC22A6 rs1158626 was associated with increased affinity for antiretroviral drugs. Genetic diversity in SLC and ABC transporters in African populations has implications for conventional therapies, notably in tuberculosis and HIV. More PK and PD data in African populations are needed to assess potential for a different response to drugs compared with other global populations.

A survey of clarithromycin monotherapy and long-term administration of ethambutol for patients with MAC lung disease in Japan: A retrospective cohort study using the database of health insurance claims.

BACKGROUND: The number of patients with nontuberculous mycobacteriosis (NTM) has increased exponentially in recent years. In Japan, approximately 88.8% of patients with NTM suffer from Mycobacterium avium-intracellulare complex (MAC) lung disease. Incidence of MAC lung disease is increasing in particularly among the middle-aged and elderly women owing to a rapid increase in nontuberculous mycobacterial infections. General treatment for MAC lung disease is chemotherapy. The type of chemotherapy recommended by specialists to prevent the development of a drug-resistant strain of the bacteria consists of a combination of clarithromycin (CAM), rifampicin, and ethambutol (EB). CAM monotherapy is contraindicated by specialists owing to its high potential to induce drug-resistant bacterial strains in patients with MAC lung disease. In addition, administering EB at doses not less than 1000 mg d-1 is not recommended to avoid adverse drug reactions. However, it is unclear how much such treatment cases exist in real world clinical settings. This is because no long-term investigation has been carried out. MATERIALS AND METHODS: This study investigated treatment with these drugs from 2005 to 2017, by studying 1135 patients with MAC lung disease based on health insurance claims database. RESULTS: Results showed that approximately 9.2% (101 cases) were prescribed long-term CAM monotherapy for 3 months or longer and approximately 3.6% (18 cases) were prescribed high doses of EB. CONCLUSION: CAM monotherapy over a long period of time is potentially detrimental to some patients. Better awareness of the types of treatments and their potential negative effects will be beneficial to clinical practitioners.