A four-month gatifloxacin-containing regimen for treating tuberculosis.

BACKGROUND: Shortening the course of treatment for tuberculosis would be a major improvement for case management and disease control. This phase 3 trial assessed the efficacy and safety of a 4-month gatifloxacin-containing regimen for treating rifampin-sensitive pulmonary tuberculosis. METHODS: We conducted a noninferiority, randomized, open-label, controlled trial involving patients 18 to 65 years of age with smear-positive, rifampin-sensitive, newly diagnosed pulmonary tuberculosis in five sub-Saharan African countries. A standard 6-month regimen that included ethambutol during the 2-month intensive phase was compared with a 4-month regimen in which gatifloxacin (400 mg per day) was substituted for ethambutol during the intensive phase and was continued, along with rifampin and isoniazid, during the continuation phase. The primary efficacy end point was an unfavorable outcome (treatment failure, recurrence, or death or study dropout during treatment) measured 24 months after the end of treatment, with a noninferiority margin of 6 percentage points, adjusted for country. RESULTS: A total of 1836 patients were assigned to the 4-month regimen (experimental group) or the standard regimen (control group). Baseline characteristics were well balanced between the groups. At 24 months after the end of treatment, the adjusted difference in the risk of an unfavorable outcome (experimental group [21.0%] minus control group [17.2%]) in the modified intention-to-treat population (1356 patients) was 3.5 percentage points (95% confidence interval, -0.7 to 7.7). There was heterogeneity across countries (P=0.02 for interaction, with differences in the rate of an unfavorable outcome ranging from -5.4 percentage points in Guinea to 12.3 percentage points in Senegal) and in baseline cavitary status (P=0.04 for interaction) and body-mass index (P=0.10 for interaction). The standard regimen, as compared with the 4-month regimen, was associated with a higher dropout rate during treatment (5.0% vs. 2.7%) and more treatment failures (2.4% vs. 1.7%) but fewer recurrences (7.1% vs. 14.6%). There was no evidence of increased risks of prolongation of the QT interval or dysglycemia with the 4-month regimen. CONCLUSIONS: Noninferiority of the 4-month regimen to the standard regimen with respect to the primary efficacy end point was not shown. (Funded by the Special Program for Research and Training in Tropical Diseases and others; ClinicalTrials.gov number, NCT00216385.)

Shifts in Mycobacterial Populations and Emerging Drug-Resistance in West and Central Africa.

In this study, we retrospectively analysed a total of 605 clinical isolates from six West or Central African countries (Benin, Cameroon, Central African Republic, Guinea-Conakry, Niger and Senegal). Besides spoligotyping to assign isolates to ancient and modern mycobacterial lineages, we conducted phenotypic drug-susceptibility-testing for each isolate for the four first-line drugs. We showed that phylogenetically modern Mycobacterium tuberculosis strains are more likely associated with drug resistance than ancient strains and predict that the currently ongoing replacement of the endemic ancient by a modern mycobacterial population in West/Central Africa might result in increased drug resistance in the sub-region

A care pathway analysis of tuberculosis patients in benin: Highlights on direct costs and critical stages for an evidence-based decision-making.

BACKGROUND:Free tuberculosis control fail to protect patients from substantial medical and non-medical expenditure, thus a greater degree of disaggregation of patient cost is needed to fully capture their context and inform policymaking. METHODS:A retrospective cross-sectional study was conducted on a convenience sample of six health districts of Southern Benin. From August 2008 to February 2009, we recruited all smear-positive pulmonary tuberculosis patients treated under the national strategy in the selected districts. Direct out-of-pocket costs associated with tuberculosis, time delays, and care-seeking pattern were collected from symptom onset to end of treatment. RESULTS:Population description and outcome data were reported for 245 patients of whom 153 completed their care pathway. For them, the median overall direct cost was USD 183 per patient. Payments to traditional healers, self-medication drugs, travel, and food expenditures contributed largely to this cost burden. Patient, provider, and treatment delays were also reported. Pre-diagnosis and intensive treatment stages were the most critical stages, with median expenditure of USD 43 per patient and accounting for 38% and 29% of the overall direct cost, respectively. However, financial barriers differed depending on whether the patient lived in urban or rural areas. CONCLUSIONS:This study delivers new evidence about bottlenecks encountered during the TB care pathway. Financial barriers to accessing the free-of-charge tuberculosis control strategy in Benin remain substantial for low-income households. Irregular time delays and hidden costs, often generated by multiple visits to various care providers, impair appropriate patient pathways. Particular attention should be paid to pre-diagnosis and intensive treatment. Cost assessment and combined targeted interventions embodied by a patient-centered approach on the specific critical stages would likely deliver better program outcomes

A semimechanistic pharmacokinetic-enzyme turnover model for rifampin autoinduction in adult tuberculosis patients.

The currently recommended doses of rifampin are believed to be at the lower end of the dose-response curve. Rifampin induces its own metabolism, although the effect of dose on the extent of autoinduction is not known. This study aimed to investigate rifampin autoinduction using a semimechanistic pharmacokinetic-enzyme turnover model. Four different structural basic models were explored to assess whether different scaling methods affected the final covariate selection procedure. Covariates were selected by using a linearized approach. The final model included the allometric scaling of oral clearance and apparent volume of distribution. Although HIV infection was associated with a 30% increase in the apparent volume of distribution, simulations demonstrated that the effect of HIV on rifampin exposure was slight. Model-based simulations showed close-to-maximum induction achieved after 450-mg daily dosing, since negligible increases in oral clearance were observed following the 600-mg/day regimen. Thus, dosing above 600 mg/day is unlikely to result in higher magnitudes of autoinduction. In a typical 55-kg male without HIV infection, the oral clearance, which was 7.76 liters · h⁻¹ at the first dose, increased 1.82- and 1.85-fold at steady state after daily dosing with 450 and 600 mg, respectively. Corresponding reductions of 41 and 42%, respectively, in the area under the concentration-versus-time curve from 0 to 24 h were estimated. The turnover of the inducible process was estimated to have a half-life of approximately 8 days in a typical patient. Assuming 5 half-lives to steady state, this corresponds to a duration of approximately 40 days to reach the induced state for rifampin autoinduction

Evaluation of initial and steady-state gatifloxacin pharmacokinetics and dose in pulmonary tuberculosis patients by using monte carlo simulations.

A 4-month regimen of gatifloxacin with rifampin, isoniazid, and pyrazinamide is being evaluated for the treatment of tuberculosis in a phase 3 randomized controlled trial (OFLOTUB). A prior single-dose study found that gatifloxacin exposure increased by 14% in the combination. The aims of the study are to evaluate the initial and steady-state pharmacokinetics of gatifloxacin when daily doses are given to patients with newly diagnosed drug-sensitive pulmonary tuberculosis as part of a combination regimen and to evaluate the gatifloxacin dose with respect to the probability of attaining a pharmacokinetic/pharmacodynamic target. We describe the population pharmacokinetics of gatifloxacin from the first dose to a median of 28 days in 169 adults enrolled in the OFLOTUB trial in Benin, Guinea, Senegal, and South Africa. The probability of achieving a ratio of ≥125 for the area under the concentration time curve to infinity (AUC0-∞) for the free fraction of gatifloxacin over the MIC (fAUC/MIC) was investigated using Monte Carlo simulations. The median AUC0-∞ of 41.2 μg · h/ml decreased on average by 14.3% (90% confidence interval [CI], -90.5% to +61.5%) following multiple 400-mg daily doses. At steady state, 90% of patients achieved an fAUC/MIC of ≥125 only when the MIC was <0.125 μg/ml. We conclude that systemic exposure to gatifloxacin declines with repeated daily 400-mg doses when used together with rifampin, isoniazid, and pyrazinamide, thus compensating for any initial increase in gatifloxacin levels due to a drug interaction. (The OFLOTUB study has been registered at ClinicalTrials.gov under registration no. NCT00216385.)

Direct out-of-pocket cost for tuberculosis in every stage of the patient care pathway (in USD).

<p>Median direct costs ranged from USD 2.10 per patient for treatment initiation to USD 43.40 per patient for intensive treatment. Pre-diagnosis and intensive treatment showed the highest median costs in both regions. Rural residents also incurred high burden during diagnosis stage.</p><p>*n1 = number of patients with direct cost >0 per stage; n2 = number of patients respectively who went through up to the intensive treatment stage (245), and who went through the entire care pathway (153).</p><p>**The median (iqr) share of overall direct cost across stages by region was: 44.0% (14.1–67.6) for pre-diagnosis, 8.5% (4.3–19.3) for diagnosis, 1.1% (0.4–2.9) for treatment initiation, 30.2% (16.2–49.8) for intensive treatment and 15.4% (2.0–29.5) for continuation treatment among urban residents, and respectively 32.1% (14.1–51.7), 27.3% (11.4–52.4), 2.2% (0.9–5.7), 22.2% (13.2–41.3) and 8.6% (3.4–22.7) among rural residents.</p><p>***Distributions of proportion significantly different across region (P<0.05).</p

Participants’ selection and data collection process.

<p>Involving clinical heads to facilitate the selection process of the participants allowed to be comprehensive and to capture the target population. Similarly, several precautions were implemented at the different stages of the process to ensure best quality data.</p

Flow diagram of the study participants.

<p>All participants (245/245) reported research outcomes from onset of their TB symptoms to intensive treatment while a smaller proportion of participants (153/245) reported research outcomes for their overall care pathway.</p

Demographic and clinical pattern of the participants.

<p>Demographic and clinical pattern of the participants.</p