COVID-19 impact on health service- and TB-related practices among private providers in Indonesia

SETTING

The COVID-19 pandemic has caused disruptions to healthcare services worldwide, including in private healthcare facilities (HCFs), where TB patients mostly initiate their care-seeking journey.

OBJECTIVE

To identify adjustments to TB-related practices made by HCFs during the pandemic.

DESIGN

We identified, contacted and invited private HCFs across West Java, Indonesia, to fill an online questionnaire. The questionnaire explored participants' sociodemographic characteristics, adaptations and TB management practices implemented in their facilities during the pandemic. Data were analysed using descriptive statistics.

RESULTS

Of the 240 HCFs surveyed, 40.0% shortened their operational hours and 21.3% have ever closed their practices during the pandemic; 217 (90.4%) made adjustments to keep delivering services, 77.9% by requiring the use of personal protective equipment (PPE); 137 (57.1%) observed fewer patient visits; 140 (58.3%) used telemedicine, a few of which (7.9%) ever handled TB patients on that platform. Respectively 89.5%, 87.5% and 73.3% of HCFs referred patients for chest radiography, smear microscopy and Xpert testing. Only a median of 1 (IQR 1-3) TB patient per month was diagnosed by the HCFs.

CONCLUSION

Two major adaptations rolled out during COVID-19 were the use of telemedicine and PPE. Optimisation of the diagnostic referral system to increase TB case detection in private HCFs is warranted.

Diabetes characteristics and long-term management needs in diabetic TB patients

BACKGROUND: Diabetes mellitus (DM) is common among patients with TB. We assessed DM characteristics and long-term needs of DM-TB patients after completing TB treatment.METHODS: Newly diagnosed TB patients with DM were recruited for screening in a randomised clinical trial evaluating a simple algorithm to improve glycaemic control during TB treatment. DM characteristics, lifestyle and medication were compared before and after TB treatment and 6 months later. Risk of cardiovascular disease (CVD), albuminuria and neuropathy were assessed after TB treatment.RESULTS: Of 218 TB-DM patients identified, 170 (78%) were followed up. Half were males, the mean age was 53 years, 26.5% were newly diagnosed DM. High glycated haemoglobin at TB diagnosis (median 11.2%) decreased during TB treatment (to 7.4% with intensified management and 8.4% with standard care), but this effect was lost 6 months later (9.3%). Hypertension and dyslipidemia contributed to a high 10-year CVD risk (32.9% at month 6 and 35.5% at month 12). Neuropathy (33.8%) and albuminuria (61.3%) were common. After TB treatment, few patients used CVD-mitigating drugs.CONCLUSION: DM in TB-DM patients is characterised by poor glycaemic control, high CVD risk, and nephropathy. TB treatment provides opportunities for better DM management, but effort is needed to improve long-term care.

Implementing the 4R and 9H regimens for TB preventive treatment in Indonesia

BACK GROUND:

The implementation of tuberculosis preventive treatment (TPT) is challenging especially in resource-limited settings. As part of a Phase 3 trial on TPT, we described our experience with the use of rifampicin for 4 months (4R) and isoniazid for 9 months (9H) in Indonesia.

METHODS:

In 2011–2017, children and adults with latent TB infection were randomised to either 4R or 9H and followed until 16 months after randomisation for children and 28 months for adults. The primary outcome was the treatment completion rate. Secondary outcomes were Grade 3–5 adverse events (AEs), active TB occurrence, and health costs.

RESULTS:

A total of 157 children and 860 adults were enrolled. The 4R treatment completion rate was significantly higher than that of 9H (78.7% vs. 65.5%), for a rate difference of 13.2% (95% CI 7.1–19.2). No Grade 3–5 AEs were reported in children; in adults, it was lower in 4R (0.4%) compared to 9H (2.8%). The incidence of active TB was lower with 4R than with 9H (0.09/100 person-year vs. 0.36/100 person-year) (rate difference: −0.36/100 person-year). The total cost per patient was lower for the 4R regimen than for the 9H regimen (USD151.9 vs. USD179.4 in adults and USD152.9 vs. USD206.5 in children)

CONCLUSIONS:

Completion and efficacy rates for 4R were better than for 9H. Compared to 9H, 4R was cheaper in all age groups, safer in adults and equally safe in children. The Indonesian TB program could benefit from these benefits of the 4R regimen.

Educational counselling of patients with combined TB and diabetes mellitus: a randomised trial

SETTING

Newly diagnosed pulmonary TB with diabetes mellitus (DM) comorbidity attending clinics in Bandung City, Indonesia.

OBJECTIVE

To describe the effect of educational counselling on patients' knowledge about TB (transmission, treatment, risk factors) and DM (symptoms, treatment, complications, healthy lifestyle), adherence to medication, and to assess characteristics associated with knowledge.

DESIGN

All patients received counselling and were then randomised to either structured education on TB-DM, combined with clinical monitoring and medication adjustment (intervention arm), or routine care (control arm). Knowledge and adherence were assessed using a questionnaire.

RESULTS

Baseline and 6-month questionnaires were available for 108 of 150 patients randomised (60/76 in the intervention arm and 48/74 in the control arm). Patients knew less about DM than about TB. There was no significant difference in the proportion with knowledge improvement at 6 months, both for TB (difference of differences 14%; P = 0.20) or for DM (10%; P = 0.39) between arms. Intervention arm patients were more likely to adhere to taking DM medication, with fewer patients reporting ever missing oral DM drugs than those in the control arm (23% vs. 48%; P = 0.03). Higher education level was associated with good knowledge of both TB and DM.

CONCLUSIONS

Structured education did not clearly improve patients' knowledge. It was associated with better adherence to DM medication, but this could not be attributed to education alone. More efforts are needed to improve patients' knowledge, especially regarding DM.

Early chest X-ray in persons with presumptive tuberculosis increases Xpert® MTB/RIF diagnostic yield and efficiency

Adult presumptive tuberculosis (TB) patients (n = 1690) were screened for TB using a questionnaire, chest X-ray (CXR) and sputum microscopy for acid-fast bacilli (AFB); Mycobacterium tuberculosis culture was performed for 74% of the patients and Xpert^® MTB/RIF was done for 17.2%. Among patients recruited, 943 (55.8%) were diagnosed with TB, of whom 870 (92.3%) were bacteriologically confirmed and 73 (7.7%) were clinically diagnosed on the basis of CXR. Using CXR prior to culture or Xpert testing reduces the number needed to screen from 7.6 to 5.0. Using CXR to triage for culture or Xpert testing reduces the number of missed cases and increases the efficiency of culture and Xpert testing.

Computer-assisted chest radiography reading for tuberculosis screening in people living with diabetes mellitus

BACKGROUND

Diabetes mellitus is a significant risk factor for tuberculosis (TB). We evaluated the performance of computer-aided detection for tuberculosis (CAD4TB) in people living with diabetes mellitus (PLWD) in Indonesia.

METHODS

PLWD underwent symptom screening and chest X-ray (CXR); sputum was examined in those with positive symptoms and/or CXR. Digital CXRs were scored using CAD4TB and analysed retrospectively using clinical and microbiological diagnosis as a reference. The area under the receiver operator curve (AUC) of CAD4TB scores was determined, and an optimal threshold score established. Agreement between CAD4TB and the radiologist's reading was determined.

RESULTS

Among 346 included PLWD, seven (2.0%) had microbiologically confirmed and two (0.6%) had clinically diagnosed TB. The highest agreement of CAD4TB with radiologist reading was achieved using a threshold score of 70 (κ = 0.41, P < 0.001). The AUC for CAD4TB was 0.89 (95%CI 0.73-1.00). A threshold score of 65 for CAD4TB resulted in a sensitivity, specificity, positive predictive value and negative predictive value of respectively 88.9% (95%CI 51.8-99.7), 88.5% (95%CI 84.6-91.7), 17.0% (95%CI 7.6-30.8) and 99.6% (95%CI 98.2-100). With this threshold, 48 (13.9%) individuals needed microbiological examination and no microbiologically confirmed cases were missed.

CONCLUSIONS

CAD4TB has potential as a triage tool for TB screening in PLWD, thereby significantly reducing the need for microbiological examination.

Point of care HbA1c level for diabetes mellitus management and its accuracy among tuberculosis patients: a study in four countries

BACKGROUND

Diabetes mellitus (DM) is common among tuberculosis (TB) patients and often undiagnosed or poorly controlled. We compared point of care (POC) with laboratory glycated haemoglobin (HbA_1c) testing among newly diagnosed TB patients to assess POC test accuracy, safety and acceptability in settings in which immediate access to DM services may be difficult.

METHODS

We measured POC and accredited laboratory HbA_1c (using high-performance liquid chromatography) in 1942 TB patients aged 18 years recruited from Peru, Romania, Indonesia and South Africa. We calculated overall agreement and individual variation (mean ± 2 standard deviations) stratified by country, age, sex, body mass index (BMI), HbA_1c level and comorbidities (anaemia, human immunodeficiency virus [HIV]). We used an error grid approach to identify disagreement that could raise significant concerns.

RESULTS

Overall mean POC HbA_1c values were modestly higher than laboratory HbA_1c levels by 0.1% units (95%CI 0.1-0.2); however, there was a substantial discrepancy for those with severe anaemia (1.1% HbA_1c, 95%CI 0.7-1.5). For 89.6% of 1942 patients, both values indicated the same DM status (no DM, HbA_1c <6.5%) or had acceptable deviation (relative difference <6%). Individual agreement was variable, with POC values up to 1.8% units higher or 1.6% lower. For a minority, use of POC HbA_1c alone could result in error leading to potential overtreatment (n = 40, 2.1%) or undertreatment (n = 1, 0.1%). The remainder had moderate disagreement, which was less likely to influence clinical decisions.

CONCLUSION

POC HbA_1c is pragmatic and sufficiently accurate to screen for hyperglycaemia and DM risk among TB patients.

Feasibility of two active case finding approaches for detection of tuberculosis in Bandung City, Indonesia

Setting: A community health clinic catchment area in the eastern part of Bandung City, Indonesia. Objective: To evaluate the feasibility of two different screening interventions using community health workers (CHWs) in detecting tuberculosis (TB) cases. Design: This was a feasibility study of 1) house-to-house TB symptom screening of five randomly selected 'neighbourhoods' in the catchment area, and 2) selected screening of household contacts of TB index patients and their neighbouring households. Acceptability was assessed through focus group discussions with key stakeholders. Results: Of 5100 individuals screened in randomly selected neighbourhoods, 48 (0.9%) reported symptoms, of whom 38 provided sputum samples; no positive TB was found. No TB cases were found among the 88 household contacts or the 423 neighbourhood contacts. With training, regular support and supervision from research staff and local community health centre staff, CHWs were able to undertake screening effectively, and almost all householders were willing to participate. Conclusion: The use of CHWs for TB screening could be integrated into routine practice relatively easily in Indonesia. The effectiveness of this would need further exploration, particularly with the use of improved diagnostics such as chest X-ray and sputum culture.

Mycobacterium tuberculosis genotypic drug resistance patterns and clustering in Jayapura, Papua, Indonesia

BACKGROUND

Little is known about drug-resistant tuberculosis (TB) and its transmission in Papua, which has one of the highest rates of TB in Indonesia.

DESIGN

We examined genotypic drug resistance patterns using multiplex ligation-dependent probe amplification and the degree of molecular clustering using 24-locus mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) among 199 consecutive pulmonary TB patients in Jayapura, Papua.

RESULTS

Drug resistance mutations were present in 30/198 (15.2%) patients: 16/144 (11.1%) primary cases and 14/51 (27.5%) retreatment cases. Genotypic resistance to rifampicin was found in 15 (7.6%) patients, to isoniazid in 19 (9.6%), to ethambutol in 7 (3.5%), and to streptomycin and second-line injectable drugs in 5 (2.5%) patients. Eight (4.0%) patients had multidrug-resistant TB, while no mutations were found for fluoroquinolones. The most common lineage found among all isolates was East-African Indian (n = 66, 33.7%), followed by Euro-American (n = 38, 19.4%). Drug resistance mutations were more common among Beijing strains than other lineages. Of the 30 drug-resistant isolates, 12 (40.0%) fell into four clusters that were separate from drug-susceptible clusters as determined using MIRU-VNTR.

CONCLUSIONS

These are the first genotypic drug resistance data from Jayapura, Papua, showing moderate rates of resistance to first-line drugs and likely transmission of drug-resistant TB.

Study of viremic profile in febrile specimens of chikungunya in Bandung, Indonesia

BACKGROUND

Data regarding the viremia profile of chikungunya virus (CHIKV) infected patients especially during the pre-febrile period is limited.

OBJECTIVE

To obtain virological kinetic data on CHIKV infections.

STUDY DESIGN

A two-week community observation for dengue transmission was conducted in Bandung, Indonesia, from 2005 to 2009. Acute specimens from non-dengue febrile patients were screened by pan-alphavirus conventional RT-PCR. The positives were confirmed for CHIKV RNA by a specific RT-PCR followed by sequencing. Simultaneously these specimens were also cultured in Vero cells and tested for anti-CHIK IgM MAC-ELISA. All the available serial specimens,including the pre-febrile specimens, from confirmed CHIK cases, were tested by virus isolation, RT-PCR, qRT-PCR, and CHIK IgM ELISA.

RESULTS

There were five laboratory confirmed CHIK cases identified and studied. Among these, viremia was determined to extend from as early as 6 days prior to until 13 days post fever onset. Quantitative RT-PCR showed viremia peaked at or near onset of illness.

CONCLUSION

In this study, individuals were identified with viremia prior to fever onset and extending beyond the febrile phase. This extended viremic phase has the potential to impact transmission dynamics and thus the public health response to CHIK outbreaks.

Platelet function alterations in dengue are associated with plasma leakage

Severe dengue is characterised by thrombocytopenia, plasma leakage and bleeding. Platelets are important for preservation of endothelial integrity. We hypothesised that platelet activation with secondary platelet dysfunction contribute to plasma leakage. In adult Indonesian patients with acute dengue, we measured platelet activation status and the response to the platelet agonist TRAP using flow cytometer-based assays. Patients were monitored daily for plasma leakage by ultrasonography. Acute dengue was associated with platelet activation with an increased expression of the activated fibrinogen receptor (αIIbβ3), the lysosomal marker CD63 and the alpha-granule marker CD62P (P-selectin). Upon maximal platelet activation by TRAP, platelet function defects were observed with a significantly reduced maximal activated αIIbβ3 and CD63 expression and reduced platelet-monocyte and platelet-neutrophil complexes. Patients in the lowest tertile of activated αIIbβ3 and CD63 expression had an odds ratio for plasma leakage of 5.2 (95% confidence interval [CI] 1.3-22.7) and 3.9 (95% CI 1.1-13.7), respectively, compared to the highest tertile. Platelet-derived serotonin has previously been related to plasma leakage and we found increased intra-platelet serotonin concentrations in our patients. In conclusion, platelet activation with platelet function alterations can be found in patients with acute dengue and this may contribute to dengue-associated plasma leakage.

QuantiFERON®-TB Gold In-Tube assay vs. tuberculin skin test in Indonesian children living with a tuberculosis case

SETTING AND OBJECTIVES

The tuberculin skin test (TST) has limitations in diagnosing latent tuberculosis (TB) infection (LTBI). Interferon-gamma release assays may improve diagnostic accuracy. We compared QuantiFERON®-TB Gold In-Tube (QFT-GIT) and TST in Indonesian children.

DESIGN

Children aged from 6 months to 9 years exposed to a TB case at household and neighbourhood levels were recruited. The children underwent QFT-GIT and TST. Test responsiveness was assessed according to an exposure gradient.

RESULTS

A total of 299 household-exposed and 72 neighbourhood-exposed children were analysed. Overall, respectively 46% and 41% were positive using QFT-GIT and the TST. Test positivity increased with exposure (QFT-GIT P value for trend <0.001, and TST P < 0.001); however, only QFT-GIT responded significantly to a 'within-household' gradient. The TST was less likely to be positive than the QFT-GIT in neighbourhood-exposed children (P = 0.05). BCG-vaccinated children were less likely to be QFT-GIT-positive, while older children were more likely to be QFT-GIT-positive. Both tests had increasing positivity with increasing smear grade.

CONCLUSION

QFT-GIT performed similarly to the TST in Indonesian children living with an infectious TB case. Test accuracy was not compromised by young age or BCG vaccination. Our findings suggest that QFT-GIT offers little advantage over the TST in this population. High rates of LTBI diagnosed in household-exposed children by both tests support preventive therapy.

A step-wise approach to find a valid and feasible method to detect non-adherence to tuberculosis drugs

A step-wise approach to identify valid and feasible methods to detect non-adherence to tuberculosis drugs was evaluated in a prospective study among pulmonary tuberculosis patients in an outpatient clinic in Indonesia. First, adherence was measured by self-reporting with the standardized Morisky questionnaire, physician assessment, pill-count, visit attendance, diary and an electronic medication event monitoring system (MEMS). Next, validity of single methods was assessed against MEMS as gold standard. Feasibility of methods was then judged by physicians in the field. Finally, when valid and feasible methods were combined, it appeared that self-reporting by a questionnaire plus physician assessment could identify all non-adherent patients. It is recommended to use a systematic approach to develop a valid and locally feasible combination of methods to detect non-adherence to TB drugs.

Rifampicin Reduces Plasma Concentrations of Moxifloxacin in Patients with Tuberculosis

BACKGROUND

The long duration of the current tuberculosis (TB) treatment is demanding and warrants the development of new drugs. Moxifloxacin shows promising results and may be combined with rifampicin to shorten the duration of TB treatment. Rifampicin induces the phase II metabolic enzymes that are involved in the biotransformation of moxifloxacin. Therefore, the interaction between rifampicin and moxifloxacin should be investigated.

PATIENTS AND METHODS

Nineteen Indonesian patients with pulmonary TB who were in the last month of their TB treatment completed a 1-arm, 2-period, fixed-order pharmacokinetic study. In phase 1 of the study, they received 400 mg of moxifloxacin every day for 5 days in addition to 450 mg of rifampicin and 600 mg of isoniazid 3 times per week. In phase 2 of the study, after a 1-month washout period, patients received moxifloxacin for another 5 days (without rifampicin and isoniazid). A 24-h pharmacokinetic curve for moxifloxacin was recorded on the last day of both study periods, and its pharmacokinetic parameters were evaluated for an interaction with rifampicin, using a bioequivalence approach.

RESULTS

Coadministration of moxifloxacin with rifampicin and isoniazid resulted in an almost uniform decrease in moxifloxacin exposure (in 18 of 19 patients). The geometric means for the ratio of phase 1 area under the curve to phase 2 area under the curve and for the ratio of phase 1 peak plasma concentration to phase 2 peak plasma concentration were 0.69 (90% confidence interval, 0.65-0.74) and 0.68 (90% confidence interval, 0.64-0.73), respectively. The median time to reach peak plasma concentration for moxifloxacin was prolonged from 1 h to 2.5 h when combined with rifampicin and isoniazid (P=.003).

CONCLUSIONS

Coadministration of moxifloxacin with intermittently administered rifampicin and isoniazid results in reduced moxifloxacin plasma concentrations, which is most likely the result of induced glucuronidation or sulphation by rifampicin. Further studies are warranted to evaluate the impact of the interaction on the outcome of TB treatment.

Plasma granulysin levels and cellular interferon-gamma production correlate with curative host responses in tuberculosis, while plasma interferon-gamma levels correlate with tuberculosis disease activity in adults

Granulysin is a recently identified cytolytic protein which is expressed by human cytotoxic T-lymphocytes and natural killer (NK)-cells, and has broad antimicrobial and tumoricidal activity. Circulating granulysin levels are associated with T- and NK-cell activity, and may thus reflect protection-associated cellular immune responses. In a case-control study in Indonesia, a highly tuberculosis (TB)-endemic country, we therefore determined plasma granulysin levels in adults with active pulmonary TB before, during, and after TB treatment, both in mild/moderate-TB and advanced-TB patients, and compared these to healthy neighbourhood controls. Adults with active pulmonary TB had significantly lower plasma granulysin levels compared to controls. After 2 months of anti-TB therapy, levels in TB patients had significantly increased, reaching values similar to those in controls. Plasma granulysin levels further increased after completion of TB therapy, being significantly higher than those in controls. Plasma granulysin levels correlated inversely with TB disease activity but not with TB disease severity. In contrast, plasma interferon-gamma (IFN-gamma) levels were significantly higher in active TB cases than in controls, normalised during treatment and correlated with both TB disease activity and TB disease severity. At the cellular level, granulysin and IFN-gamma expression both correlated inversely with disease activity. Interestingly, granulysin was predominantly expressed by IFN-gamma negative T-cells, suggesting that the cellular sources of IFN-gamma and granulysin in TB are partly non-overlapping. The observation that plasma granulysin levels and cellular IFN-gamma production correlate with curative host responses in pulmonary tuberculosis points to a potentially important role of granulysin, next to IFN-gamma, in host defence against M. tuberculosis.

Diabetes mellitus is strongly associated with tuberculosis in Indonesia

SETTING

Diabetes mellitus is a known risk factor for tuberculosis (TB), but no studies have been reported from South-East Asia, which has a high burden of TB and a rapidly growing prevalence of diabetes.

OBJECTIVE

To examine if and to what extent diabetes is associated with an increased risk of TB in an urban setting in Indonesia.

DESIGN

Case-control study comparing the prevalence of diabetes mellitus (fasting blood glucose level >126 mg/dl) among newly diagnosed pulmonary TB patients and matched neighbourhood controls.

RESULTS

Patients and control subjects had a similar age (median 30 years) and sex distribution (52% male), but malnutrition was more common among TB patients (median body mass index 17.7 vs. 21.5 kg/m2). HIV infection was uncommon (1.5% of patients). Diabetes mellitus was present in 60 of 454 TB patients (13.2%) and 18 of 556 (3.2%) control subjects (OR 4.7; 95%CI 2.7-8.1). Adjustment for possible confounding factors did not reduce the risk estimates. Following anti-tuberculosis treatment, hyperglycaemia reverted in a minority (3.7%) of TB patients.

CONCLUSION

Diabetes mellitus is strongly associated with TB in young and non-obese subjects in an urban setting in Indonesia. This may have implications for TB control and patient care in this region.

Better patient instruction for sputum sampling can improve microscopic tuberculosis diagnosis

To examine the effect of patient instruction for provision of sputum samples, we performed a randomised controlled trial involving 174 patients with suspected tuberculosis (TB) in an urban TB clinic in Indonesia. TB was diagnosed in 50.6% of patients who received additional counselling by paramedics compared with 35.5% of patients in the control group following routine diagnostic procedure, corresponding to a 15.1% higher detection rate (95%CI 2.9-27.4). Significant differences were also found for sputum volume, consistency, positivity rate and density of acid-fast bacilli. Simple interventions such as these may increase TB case detection in Indonesia and elsewhere.

The association between prenatal and or post natal growth disorder and lipid profile in adolescents aged 12 - 15 years old in Tanjungsari Subdistrict, Sumedang, West Java

AIM

to investigate association between growth disorders in pre and post natal period and abnormal lipid profile in adolescents aged 12 -15 years old in Tanjungsari population.

METHODS

a cohort study was conducted in 3350 children who were born in 1988-1990 in Tanjungsari Subdistrict, Sumedang, West Java. A complete anthropometric data since their birth were collected from October 2002-February 2003.

INCLUSION CRITERIA

Children who had birth weight in the range of +/- 3 of standard deviation (SD). Post natal growth disorder based on Z score of height according to age group and height changes at the age of 0-12 months and 12-36 months. SGA criteria were determined based on cross tabulation between weight and birth length at birth. Study subjects were divided into control group, groups of pre natal, post natal and pre-postnatal growth disorder. All subjects were checked for lipid profiles. Statistical calculation used analysis of variance, t test and logistic regression. 312 subjects were included in this study, 73 were in control group, 90 subjects in postnatal, 96 subjects were in pre natal and 53 subjects were in pre-post natal growth disorder group.

RESULTS

this study has not shown significant difference in risk factor of having abnormal lipid profile between normal control group and growth disorder group except for those in prenatal growth disorder group with RR = 2.375 (p = 0.014).

CONCLUSION

the post natal growth disorder had not influenced lipid profile in adolescents with SGA. Recent BMI was an additional risk factor for pre-post natal growth disorder group.

Bioavailability of rifampicin in Indonesian subjects: a comparison of different local drug manufacturers

To examine the bioavailability of rifampicin formulations produced in Indonesia, we conducted a single-dose, double-blind, cross-over bioavailability study. Antituberculosis drugs from three Indonesian manufacturers and one international manufacturer were compared in 12 healthy Indonesian subjects. Out of three local manufacturers, two showed equal bioavailability compared to the reference standard, and one showed slightly lower bioavailability (ratio 0.86; 90% confidence interval 0.80-0.91) and substandard rifampicin content of drug preparations. Plasma rifampicin concentrations in this study were more than three-fold higher than concentrations recently found in tuberculosis patients in Indonesia, which suggests that unknown (disease-related) determinants may reduce the bioavailability of rifampicin formulations.

Low plasma concentrations of rifampicin in tuberculosis patients in Indonesia

SETTING

Although rifampicin is a key drug in tuberculosis treatment, little is known about its quality and bioavailability in countries endemic for tuberculosis. High drug levels may lead to increased toxicity, while low drug levels may predispose to treatment failure and relapse.

OBJECTIVE

To investigate possible variations in the bioavailability of plasma rifampicin in tuberculosis patients in Indonesia.

DESIGN

Plasma concentrations of rifampicin and the rifampicin content of drug formulations in use were measured among 62 non-selected tuberculosis patients in Jakarta, Indonesia.

RESULTS

Plasma concentrations of rifampin were generally low: 70% of patients had 2-hour plasma concentrations (Cmax) below 4 mg/L. No toxic plasma concentrations of rifampicin (>20 mg/L) were found. The strongest predictive factor for the magnitude of rifampicin concentrations was the drug manufacturer. The rifampicin content of the different drug preparations used was normal (90.5-103.6% of the reference standard). No association was found between low plasma rifampicin concentrations and delayed sputum conversion or treatment failure.

CONCLUSION

The unexpectedly low plasma concentrations of rifampicin in this setting are most likely due to reduced bioavailability of local drug preparations, as the rifampicin content of the drug preparations was found to be normal. The clinical significance of these findings remains to be determined.