Efficacy and safety of a 4-drug fixed-dose combination regimen compared with separate drugs for treatment of pulmonary tuberculosis: the Study C randomized controlled trial

CONTEXT

Fixed-dose combinations (FDCs) of drugs for treatment of tuberculosis have been advocated to prevent the emergence of drug resistance.

OBJECTIVE

To assess the efficacy and safety of a 4-drug FDC for the treatment of tuberculosis.

DESIGN, SETTING, AND PATIENTS

The Study C trial, a parallel-group, open-label, noninferiority, randomized controlled trial conducted in 11 sites in Africa, Asia, and Latin America between 2003 and 2008. Patients were 1585 adults with newly diagnosed smear-positive pulmonary tuberculosis.

INTERVENTIONS

Patients were randomized to receive daily treatment with 4 drugs (rifampicin, isoniazid, pyrazinamide, ethambutol) given as an FDC (n = 798 patients) or separately (n = 787) in the 8-week intensive phase of treatment.

MAIN OUTCOME MEASURE

Favorable treatment outcome, defined as negative culture result at 18 months post randomization and not having already been classified as unfavorable. Noninferiority was dependent on consistent results from a per-protocol and modified intention-to-treat analysis, using 2 different models for the latter, classifying all changes of treatment or refusal to continue treatment (eg, bacteriological failure/relapse, adverse event, default, drug resistance) as unfavorable (model 1) and classifying changes of treatment for reasons other than therapeutic outcomes according to their 18-month bacteriological outcome if available (post hoc model 2). The prespecified noninferiority margin was 4%.

RESULTS

In the per-protocol analysis, 555 of 591 patients (93.9%) had a favorable outcome in the FDC group vs 548 of 579 (94.6%) in the separate-drugs group (risk difference, -0.7% [90% confidence interval {CI}, -3.0% to 1.5%]). In the model 1 analysis, 570 of 684 patients (83.3%) had a favorable outcome in the FDC group vs 563 of 664 (84.8%) in the separate-drugs group (risk difference, -1.5% [90% CI, -4.7% to 1.8%]). In the post hoc model 2 analysis, 591 of 658 patients (89.8%) in the FDC group and 589 of 647 (91.0%) in the separate-drugs group had a favorable outcome (risk difference, -1.2% [90% CI, -3.9% to 1.5%]). Adverse events related to trial drugs were similarly distributed among treatment groups.

CONCLUSIONS

Compared with a regimen of separately administered drugs, a 4-drug FDC regimen for treatment of tuberculosis satisfied prespecified noninferiority criteria in 2 of 3 analyses. Although the results do not demonstrate full noninferiority of the FDCs compared with single drugs given separately using the strict definition applied in this trial, use of FDCs is preferred because of potential advantages associated with the administration of FDCs compared with separate-drug formulations.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00216333.

[A case of tuberculous lateral great adductor muscle abscess during treatment of miliary tuberculosis]

We report a rare case of a thigh abscess which appeared during treatment of miliary tuberculosis. A 72-year-old woman with a history of diabetes mellitus was being treated for systemic sclerosis with prednisolone. She was then admitted to our hospital with fever, and chest computed tomography showed an abnormal shadow. She was given a diagnosis of miliary tuberculosis, and antituberculous therapy was initiated with isoniazid, rifampicin, ethambutol and pyrazinamide. Although this combination of antituberculous drugs was effective, 3 months after the initiation of treatment, a collection of fluid appeared in her left thigh. Further examination revealed the fluid to be positive for Mycobacterium tuberculosis on PCR and negative on mycobacterial culture. We thus diagnosed this phenomenon to be a paradoxical reaction.

[Epidemiology of the resistance of Mycobacterium tuberculosis to antituberculosis drugs at the main hospital in Dakar, Senegal. A 4-year retrospective study (2000-2003)]

A retrospective study was carried out from January 2000 to December 2003 to assess the resistance of Mycobacterium tuberculosis to antituberculosis drugs and the impact of this on the treatment result. Two hundred and two patients' files were studied (average age: 36 years; sex-ratio: 1.7). Pulmonary localisation (85.7%) or extrapulmonary localisation (14.3%). HIV status is negative (71.3%), positive (10.8%) or unknown (17.9%). The overall recovery rate is 60.7% (61.4% in HIV-; 46.1% in HIV+), the rate of treatment failure is 2.7% (1.1% in HIV-; 15.4% in HIV+), the death rate due to tuberculosis is 6.3% (2.3% in HIV-; 23.1% in HIV+), and the rate of patients who disappeared from the system is 30.3% (35.2% in HIV-; 14.2% in HIV+). Hepatotoxicity that occurred during treatment is observed in 14.3% of cases (recovery: 56.2%; failure: 6.2%; lost from the system: 18.8%). Eighty-four percent of patients never received antituberculosis treatment (group A) versus 15.8% of patients who had already received one or more antituberculosis drugs (group B). The rates of resistance to isoniazid are 6.4% (A) and 12.5% (B), to rifampicin 1.7% (A) and 12.5% (B), to ethambutol 0.5% (A) and 0% (B), to streptomycin 24.1% (A) and 46.8% (B). The percentage of multiresistant strains is 1% in patients not treated previously and 11% in those who had already received antituberculosis treatment. When the patients are carriers of a strain that is responsive to the treatment administered, the recovery rate is 64.2% versus 46.7% in patients whose strain is resistant to at least one of the treatments administered.

Mediastina Tuberculosis mass in a three-month-old boy

BACKGROUND

Mediastinal mass of tuberculous origin is exceedingly rare in infant.

AIM

to report an exceedingly rare case of mediastinal mass of tuberculous origin.

CASE REPORT

We report a three-month-old boy who presented a one month history of wheezing and persistent pneumopathy. Radiological investigations showed a large posterior mediastinal mass which infiltrates lungs. Thoracoscopic biopsy showed caseous necrosis with granuloma suggestive of tuberculosis. The outcome was favourable with antituberculous chemotherapy.

CONCLUSION

Mediatinal mass of tuberculous origin should considered in differential diagnosis of mediastinal masses in children; be suggested in mediastinal mass in children.

New susceptibility breakpoints for first-line antituberculosis drugs based on antimicrobial pharmacokinetic/pharmacodynamic science and population pharmacokinetic variability

Arguably, one of the most common and consequential laboratory tests performed in the world is Mycobacterium tuberculosis susceptibility testing. M. tuberculosis resistance is defined by growth of > or =1% of a bacillary inoculum on the critical concentration of an antibiotic. The critical concentration was chosen based on inhibition of > or =95% of wild-type isolates. The critical concentration of isoniazid is either 0.2 or 1.0 mg/liter, that of rifampin is 1.0 mg/liter, that of pyrazinamide is 100 mg/liter, that of ethambutol is 5.0 mg/liter, and that of fluoroquinolones is 1.0 mg/liter. However, the relevance of these concentrations to microbiologic and clinical outcomes is unclear. Critical concentrations were identified using the ability to achieve the antibiotic area under the concentration-time curve/MIC ratio associated with > or =90% of maximal kill (EC(90)) of M. tuberculosis in > or =90% of patients. Population pharmacokinetic parameters and their variability encountered in tuberculosis patients were utilized in Monte Carlo simulations to determine the probability that particular daily doses of the drugs would achieve or exceed the EC(90) in the epithelial lining fluid of 10,000 tuberculosis patients. Failure to achieve EC(90) in > or =90% of patients at a particular MIC was defined as drug resistance. The critical concentrations of moxifloxacin and ethambutol remained unchanged, but a critical concentration of 50 mg/liter was identified for pyrazinamide, 0.0312 mg/liter and 0.125 mg/liter were defined for low- and high-level isoniazid resistance, respectively, and 0.0625 mg/liter was defined for rifampin. Thus, current critical concentrations of first-line antituberculosis drugs are overoptimistic and should be set lower. With the proposed breakpoints, the rates of multidrug-resistant tuberculosis could become 4-fold higher than currently assumed.

Drug-susceptibility patterns of Mycobacterium tuberculosis in Mpumalanga province, South Africa: possible guiding design of retreatment regimen

Multidrug-resistant tuberculosis (MDR-TB) has been a cause of concern in both developed and developing countries. The prevalence of drug resistance in Mycobacterium tuberculosis (MTB) isolates (n=692) from Mpumalanga province was assessed. In total, 692 (64%) MTB strains from cases with pulmonary TB were tested for susceptibility against rifampicin, isoniazid, ethambutol, and streptomycin using the MGIT 960 instrument. Two hundred and nine (30.2%) strains were resistant to one or more drugs. Resistance to one drug ranged from 1.4% for ethambutol to 17.7% for rifampicin. The prevalence of MDR-TB ranged from 6.7% for three drugs to 34% for four drugs, with significant predictors being patients' age-groups of 25-54 years (p=0.0012) and >55 years (p=0.007). The result showed a high level (58.4%) of MDR-TB from cases in Mpumalanga province. To achieve a higher cure rate in this province, drug-susceptibility tests must be done for every case.

[EVALUATION OF THE EFFICIENCY OF TREATMENT AND THE CHOICE OF CONTROL COMPUTED TOMOGRAPHY TIME IN CHILDREN WITH MINOR FORMS OF INTRATHORACIC TUBERCULOSIS]

Three chemotherapy regimens (Group 1: 2HRZ/4HR, n = 31; Group 2: 2HRZ/4HZ, n = 33; Group 3: 6HR, n = 33) were comparatively assessed in children with minor forms of intrathoracic tuberculosis diagnosed by the computed tomography (CT). The leading criteria for therapeutic effectiveness were regression of intoxication symptoms and changes in the CT pattern. The results of treatment were equal in all the groups. With the 6HR regimen, varying unavoidable adverse reactions were 4.3-fold less frequently (3.0 ± 3.0% and 12.5 ± 4.1%, respectively; p = 0.25). CT pattern changes by months 2-3 and 6 of therapy were compared. Single control CT investigation by 6 months of therapy was optimal. Additional CT study at 2-3 months of therapy reflected positive changes in most cases, but failed to affect treatment policy.

Rifampicin serum levels in childhood tuberculosis

BACKGROUND

Rifampicin (RMP) is an essential drug in paediatric anti-tuberculosis treatment. The current World Health Organization (WHO) guidelines recommend an oral dosage of 10 (8-12) mg per kg body weight.

OBJECTIVE

To present a study investigating RMP serum levels in children after oral medication of RMP alone and after combination treatment with ethambutol (EMB).

DESIGN

RMP serum levels in children of different age groups were determined after a single oral administration of 10 mg/kg RMP alone as well as after combination with 35 mg/kg EMB.

RESULTS

RMP serum levels were lower than those expected in adults receiving a similar oral dose. RMP serum levels in combination treatment were even lower than in monotherapy.

CONCLUSION

Currently recommended RMP dosages in childhood tuberculosis lead to serum levels lower than those recommended for adults, probably due to different pharmacokinetics and pharmacodynamics in children. In children, it appears to be more valid to calculate RMP dosage on the basis of body surface area rather than body weight, leading to higher dosages especially in younger children.

Comparison of a four-drug fixed-dose combination regimen with a single tablet regimen in smear-positive pulmonary tuberculosis

OBJECTIVE

To compare the efficacy, safety and acceptability of two short-course regimens of isoniazid, rifampicin, pyrazinamide and ethambutol (HRZE) given either as fixed-dose combination (4-FDC) tablets or as single tablets (ST) in patients with newly diagnosed pulmonary tuberculosis (PTB).

DESIGN

This randomised, open, multicentre, multinational study was conducted in 26 centres and included 1159 patients with smear-positive PTB. 4-FDC daily for 2 months then H+R for 4 months, or single preparations of H, R, Z and E for 2 months followed by H and R for 4 months were administered daily. Sputum smear conversion rates at 2, 4 and 6 months (end of treatment [EOT], primary endpoint) and at 9 and 12 months (follow-up) were measured, together with adverse events and the acceptability of the formulations.

RESULTS

Smear conversion rates for 4-FDC and ST at EOT were 80.4% (468/582 patients) vs. 82.7% (477/577) in the intent-to-treat (ITT) population, and 98.1% (404/412) vs. 98.6% (416/422) in the per-protocol (PP) subgroup. Non-inferiority of 4-FDC was demonstrated at month 2, EOT and follow-up in both the ITT and the PP populations. Overall numbers of adverse events were not significantly different between the groups.

CONCLUSION

The efficacy of the 4-FDC regimen was non-inferior to that of the ST regimens, but patient acceptability significantly improved with 4-FDC.

Coccidioides immitis and Mycobacterium tuberculosis diagnosed by endoscopic ultrasound

The use of endoscopic ultrasound in staging non-small cell lung cancer is well known. Its role in diagnosing non-malignant conditions that cause mediastinal adenopathy is still not well established. We diagnosed Coccidioides immitis and Mycobacterium tuberculosis in two patients using endoscopic ultrasound. To our knowledge this is the first case of Coccidioidomycosis to be diagnosed by endoscopic ultrasound.

[Estimation of the possibilities of using unified chemotherapy regimens in new cases of pulmonary tuberculosis in old-age children and adolescents]

A hundred and forty children aged 13 to 17 who had new-onset active pulmonary tuberculosis were examined. There was a predominance of infiltrative tuberculosis (63.6%) in the pattern of its clinical forms. The processes were more frequently disseminated (79.3%) with lung tissue decay in every two patients (55.1%) and bacterial discharge in every three patients (39.3%). Among the new cases of pulmonary tuberculosis, the proportion of its multidrug resistance was 7.9%. The routine regimens were used for treatment. The efficiency of intensive-phase (IF) treatment was evaluated in 85 patients, including 18 patients receiving chemotherapy (CT) (HRZ/E/S) regimen 3 (Group 1), 45 having CT (HRZ/E/S) regimen 1 (Group 2), and 22 having CT (HRZE[A][Fq]/[Pt]) regimen 2B (Group 3). Clinical laboratory, Xray, and microbiological findings were criteria for evaluating the efficiency of IP CT. Abacillation occurred in all cases by month 4 of therapy. By and large, the efficiency of IF CT was 90.6% in new cases of pulmonary tuberculosis among old-age children and adolescents. In patients with disseminated processes, it ranged from 81.8% (Group 3) to 91.1% (Group 2) depending on the extent of lung tissue damage. The efficiency of therapy was as high as 100% in patients with circumscribed processes. Polyresistant resistance of Mycobacterium tuberculosis (MBT) to chemical agents, including multidrug resistance (7.9%), was a main reason of ineffective IF treatment (9.4%) in new cases of pulmonary tuberculosis among old-age children and adolescents. Overall, the actual use rate of routine CT regimens was 65.9% in new cases of pulmonary tuberculosis and adolescents. Uncontrolled adverse reactions to antituberculous drugs and drug resistance in MBT were reasons for deviations of routine regimens (modifications, use of individual regimes).

[Optimization of chemotherapy regimens in children with primary pulmonary tuberculosis]

The efficiency of treatment was analyzed in 142 children aged 3-14 years who had local forms of primary pulmonary tuberculosis. Therapy was performed according to regimens 3 and 1, by using individual dosage regimens depending on the extent and severity of a specific process, the presence of complications, and age-related features. In minor tuberculosis, solitary calcifications being detected without signs of the activity of tuberculous infection, the basic course of therapy was 6-8 months; it was performed using 2 drugs in individual cases. In disseminated and complicated processes, eliminated intoxication and visible X-ray inflammatory changes were observed in 58.8-61.7% of children by months 3-4 of treatment, which required a longer intensive phase, by administering 3 drugs in the continuation phase till 6-9 months.

Isoniazid induced gynaecomastia: a case report

Gynaecomastia due to anti-tubercular chemotherapy is a rare side effect. Isoniazid causing breast tissue enlargement has been very rarely reported. We report a 60-year old, male patient of Pulmonary Tuberculosis who was started on antituberculous treatment (ATT) with rifampicin (R), isoniazid (H), ethambutol (E) and pyrazinamide (Z) together for initial two months and R, H & E thereon. After five months of initiation of treatment, while receiving RHE, he developed painful bilateral gynaecomastia. Isoniazid was stopped and patient was continued on R & E till completion of the treatment up to nine months. After stopping isoniazid, his breast swelling subsided to some extent and became non-tender. Follow up, at six months, after stopping the course of treatment, patient was asymptomatic except for slight bilateral non-tender breast enlargement.

[Long-term observation of pulmonary Mycobacterium avium complex disease treated with chemotherapy-- following the guidelines for treatment]

OBJECTIVE

We performed a long-term retrospective investigation of pulmonary Mycobacterium avium complex (MAC) disease treated with combined chemotherapy following the ATS guideline or the Japanese Society for Tuberculosis guideline. We also studied when to terminate the combined chemotherapy.

MATERIALS AND METHODS

The subjects of this study consisted of 90 patients who underwent combined chemotherapy according to these guidelines for minimum one-year period and followed up for at least one year since April, 1998.

RESULTS

The mean patients' age was 64.8 years old and the gender distribution consisted of 34 males and 56 females. While the sputum negative conversion was observed in 54 of 90 patients (60%), clinical improvement was recognized in 35 patients (39%) following combined chemotherapy administered according to the guidelines. Out of 54 patients with sputum conversion, 30 cases were followed up after the discontinuation of treatment, and sputum relapse later was seen in 18 patients. Out of 24 patients who continued the same treatment, sputum relapse was seen in 10 patients. Out of 35 patients with clinical improvement, 17 cases have been followed up after the discontinuation of treatment, clinical worsening was later recognized in 9 patients. Out of 18 patients who continued the same treatment, clinical worsening was recognized in 6 patients.

CONCLUSIONS

As the probability of sputum relapse after discontinuation of treatment was high even among patients whose sputum converted to negative by combined treatment according to the guidelines, we think that it is better to continue treatment according to the guidelines as long as possible.

Primary tuberculosis of the thyroid gland

Thyroid tuberculosis is a rare disease even in countries in which tuberculosis (TB) constitutes an endemic disorder. The diagnosis is often difficult as the clinical presentation has no distinct characteristics. We report a 47-year-old woman who presented with a painful nodular swelling of the neck, confirmed by physical examination and sweating. Ultrasonography disclosed nodules of the pyramidal lobe with cystic change, and bilateral multiple hypoechogenic lymph nodes along the jugular and carotid chains. Thyroid function tests were in the normal range, there were no signs of inflammation and the tuberculin test was negative. There was no evidence of tuberculosis in any other organ. The patient had surgery in which the pyramidal lobe was removed. Microscopic examination of the thyroid parenchyma and the excised lymph node revealed necrotizing epithelioid granulomas with Langhans' giant cells. The diagnosis of thyroid tuberculosis was therefore made. The patient was put on isoniazid, rifampicin, ethambutol and pyrazinamid for the subsequent 2 months and was subsequently given isoniazid and rifampicin for the subsequent 6 months with a favourable outcome. Although seldom observed, tuberculosis should be kept in mind in the differential diagnosis of nodular lesions of the thyroid.

[Cosyntropin test in severe active tuberculosis]

BACKGROUND

Frequency of adrenal insufficiency in patients with tuberculosis varies from 0 to 58%; however, all published series excluded severely ill patients. Our objective was to investigate adrenal insufficiency with the low-dose cosyntropin test in patients with severe active tuberculosis.

METHOD

From two large university affiliated hospitals, 18 patients with tuberculosis and criteria of sepsis or severe sepsis according to SCCM/ACCP criteria, defined by the present authors as severe active tuberculosis, participated in the study. A low-dose ACTH test with 10 mg of ACTH was performed. After ACTH test, all patients received a stress dose of hydrocortisone (240 mg/day) during their entire hospitalization along with four antituberculous drugs. Abnormal response was considered when elevation of serum cortisol was <7 microg/dl with respect to basal level, 60 min after ACTH administration.

RESULTS

Adrenal insufficiency was found in seven patients (39%); no clinical or laboratory data were associated with the presence of abnormal adrenal response. Except in one patient with HIV infection, all the signs and symptoms improved after antituberculous and hydrocortisone treatment. The increment in serum cortisol value post-ACTH test was lower in patients with hypoalbuminemia.

CONCLUSIONS

Adrenal insufficiency is frequent in severe active tuberculosis. The efficacy and security of supplemental steroid treatment in severe active tuberculosis should be established by a randomized clinical trial.

Biowaiver Monographs for Immediate Release Solid Oral Dosage Forms: Ethambutol Dihydrochloride**This paper reflects the scientific opinion of the authors and not the policies of regulating agencies.**A project of the International Pharmaceutical Federation FIP, Groupe BCS, http://www.fip.org/bcs

Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate release (IR) solid oral dosage forms containing ethambutol dihydrochloride as the only active pharmaceutical ingredient (API) are reviewed. Ethambutol dihydrochloride is a Biopharmaceutics Classification System (BCS) Class III drug with permeability properties approaching the border between BCS Class I and III. BE problems of ethambutol formulations containing different excipients and different dosages forms have not been reported and hence the risk of bioinequivalence caused by excipients is low. Ethambutol has a narrow therapeutic index related to ocular toxicity. However, as long as the prescribers' information of the test product stipulates the need for regular monitoring of ocular toxicity, the additional patient risk is deemed acceptable. It is concluded that a biowaiver can be recommended for IR solid oral dosage forms provided that the test product (a) contains only excipients present in ethambutol IR solid oral drug products approved in ICH or associated countries, for instance as presented in this paper, (b) complies with the criteria for "very rapidly dissolving" and (c) has a prescribers' information indicating the need for testing the patient's vision prior to initiating ethambutol therapy and regularly during therapy.

[Relapse rate of pulmonary tuberculosis within two years following completion of twice weekly intermittent chemotherapy]

OBJECTIVE

To evaluate the relapse rate after treatment of a twice weekly intermittent chemotherapy during continuation phase in the patients with pulmonary tuberculosis in two years period after completion of chemotherapy.

METHODS

The patients with drug susceptible pulmonary tuberculosis treated with 2HRZE/4H2R2 under the supervision by the pharmacists or the patients treated with 2HRZE/4HR by self-administration were followed-up for two years after completion of chemotherapy.

RESULTS

A total number of 135 pulmonary tuberculosis patients were treated with 2HRZE/4H2R2, 3 of 135 discontinued this intermittent treatment, and 11 of 135 completed chemotherapy was excluded from the relapse analysis, 105 out of the remaining 121 were followed-up for more than 6 months. On the other hand 240 patients were treated with 2HRZE/4HR, 37 out of 240 were excluded from the analysis, 147 of the remaining 203 were followed-up for more than 6 months. The relapse rate of this intermittent chemotherapy 1.89/100 person-year was similar to the relapse rate 1.86/100 person-year among 147 treated with daily regimen by self-administration. This difference was not statistically significant (z = 0.36, P = 0.14).

CONCLUSION

As regards relapse rate, this 2HRZE/4H2R2 regimen is effective and useful for the expansion of DOT, and it should be expanded nationally in Japan.

[Ex juvantibus diagnosis in suspected skin tuberculosis]

The paper deals with the diagnosis of cutaneous tuberculous lesions, by performing expectancy antituberculous treatment (ex juvantibus and ex nocentibus). The urgency of this problem is confirmed by the analysis of 205 cases of cutaneous tuberculosis of different clinical forms, which demonstrates that the efficiency of antituberculous therapy proved to be significant in 18.5% of cases to make a definitive diagnosis. The optimum procedure for this therapy is discussed.

Outcome of multi-drug resistant tuberculosis cases treated by individualized regimens at a tertiary level clinic

AIM

To determine the clinical, radiological and drug resistance profile as well as the factors associated with treatment outcome of Multi-Drug Resistant Tuberculosis (MDR-TB).

MATERIAL AND METHODS

All newly diagnosed patients with pulmonary MDR-TB from August 2002 to December 2004 enrolled at New Delhi Tuberculosis Centre, were included in the study. They were followed up clinically, radiologically and bacteriologically by sputum smear, culture and Drug Susceptibility Testing (DST) at regular intervals. According to their DST pattern and previous history of Anti-Tubercular Treatment (ATT), individualized treatment regimens were tailored for each patient.

RESULTS

Out of total 27 bacteriologically proven cases of MDR-TB included in this study, 19 were males (mean age and weight 38.5 years and 52.6 kgs, respectively) and eight females (mean age and weight 34.3 years and 40.7 kgs, respectively). A majority (18) were residents of Delhi and the rest hailed from different parts of North India. All of them had a history of previous treatment ranging from six to 34 months. Cavity on chest X-rays was seen in 81%, while 44% showed extensive involvement. The patients received at least four "second line drugs" during their treatment with a mean of 6.2 anti-tubercular drugs during their intensive phase. Of the 27 patients, 13 were cured, 10 defaulted, one died, one is still on treatment and two were referred for surgery. Radiological improvement was observed in two third of cases and chest X-ray of two patients showed a complete resolution. Six predictors were identified for successful outcome of MDR-TB. They include weight gain at six months, culture conversion, radiological improvement during treatment, disease with M. tuberculosis strains exhibiting resistance to less than or up to three anti-tubercular drugs, use of less than or up to three second line drugs in treatment and no change of regimen during treatment.

CONCLUSION

Default from treatment was observed to be a major challenge in the treatment of MDR-TB due to long duration and expense of ATT.

[Drug-resistant pulmonary tuberculosis at the penitentiaries]

In recent years, the penitentiaries of Russia have tended to show some stabilization of some tuberculosis indices. In 2006, its morbidity and mortality versus 1999 decreased by 3 times and amounted to 1387 and 79 per 100,000, respectively. The spread of its drug-resistant forms has a considerable impact on the deterioration of the tuberculosis epidemic situation. At present the number of patients with primary drug resistance of the total number of bacterial-discharging persons is more than 50%; multidrug resistance is observed in more than 20% of cases. The use of chemotherapy regimen IIb using fluoroquinolones in the intensive-phase chemotherapy in the treatment of destructive pulmonary tuberculosis allowed Mycobacterium tuberculosis polyresistance to isoniazid and rifampicin in combination with other first-line antituberculous agents and multidrug resistance to be overcome in 87 and 79.5% of cases, respectively.

[A surgically treated case of ileus caused by small intestinal tuberculosis during treatment for pulmonary tuberculosis]

A 44-year-old man consulted medical clinic, complaining of cough and sputum. Then he was admitted to our hospital, because of positive acid-fast bacilli in his sputum and positive PCR (polymerase chain reaction) for Mycobacterium tuberculosis. Combined use of isoniazid (INH), rifampicin (RFP), ethambutol (EB) and pyrazinamide (PZA) was started. But 4 days after starting treatment, we had to suspend tuberculosis chemotherapy because of hepatopathy. Since then he started to complain epigastralgia and vomiting. Plain abdominal X-ray and abdominal computed tomography (CT) led to a diagnosis of ileus. Inspite of insertion of ileus tube symptoms of ileus did not improve. Small bowl series showed severe stenosis at ileum end, necessitating jejunectomy. Macroscopic study revealed a ring ulcer and multiple epithelioid cell granuloma with Langhans' giant cells was detected histopathologically. PCR for M. tuberculosis of extracts from ileum was positive. Therefore the patient was diagnosed small intestinal tuberculosis. Treatment was continued by the combination of INH, RFP, EB, and the symptoms markedly improved. There have been no sign of recurrence since the end of the 6-month treatment for tuberculosis.

Targeted drug delivery to enhance efficacy and shorten treatment duration in disseminated Mycobacterium avium infection in mice

OBJECTIVES

Improvement of the efficacy of drug treatment in mycobacterial infection by the development and application of targeted drug delivery.

METHODS

In disseminated Mycobacterium avium infection in mice, the relative efficacy of the antimycobacterial agents that are currently used in combination therapy was investigated. Next, the effect of the addition of targeted delivery of amikacin to the infected tissues in the initial phase of treatment was studied. Amikacin was chosen because of its unique rapid and high mycobacterial killing capacity. As drug delivery tool, long-circulating sterically stabilized liposomes were used.

RESULTS

Treatment with clarithromycin alone daily (6 days a week) slowly killed most of the mycobacteria in the lung, liver, spleen, inguinal and mesenterial lymph nodes. However, after 24 weeks of treatment, persistence of substantial numbers of mycobacteria in the infected organs was observed. The addition of ethambutol to the clarithromycin regimen did not significantly enhance the efficacy of treatment, neither did rifampicin as a third agent. In contrast, the addition of liposomal amikacin in the initial phase of therapy resulted in rapid and complete elimination of the mycobacteria in all infected organs within 12 weeks of treatment without relapse of infection. As a result, total treatment duration could be significantly reduced to 12 weeks.

CONCLUSIONS

In M. avium infection in mice, the approach of targeted drug delivery was successful. The rapid decrease in the mycobacterial load followed by complete killing, including the persistent mycobacteria considered responsible for relapse of infection, allows a significant reduction of the total treatment duration.

Ethambutol in paediatric tuberculosis: aspects of ethambutol serum concentration, efficacy and toxicity in children

SETTING

Ethambutol (EMB) is used as a fourth drug in paediatric anti-tuberculosis treatment. In current recommendations the dosage of EMB is calculated per kg body weight.

OBJECTIVE

To present two studies investigating an appropriate EMB dosage in children, and observational data on its toxicity and efficacy.

DESIGN

EMB serum levels in children of different age groups were determined after single oral administration of EMB alone as well as after EMB combined with rifampicin, and optimal dosages were established. The efficacy and toxicity of these EMB dosages were examined retrospectively.

RESULTS

EMB serum levels were lower than those expected in adults receiving a similar oral dose, due to different pharmacokinetics and pharmacodynamics in childhood. Thereafter, children were treated with EMB doses calculated by body surface (867 mg/m2). Ocular toxicity occurred in 0.7% of cases and relapses in 0.8%.

CONCLUSION

Current recommended EMB dosages in childhood tuberculosis lead to subtherapeutic serum levels. It appears to be more valid to calculate the EMB dosage on the basis of body surface rather than body weight, leading to higher dosages especially in younger children. With these dosages, therapeutic serum levels are reached in all age groups, leading to a high efficacy of anti-tuberculosis treatment without increased ocular toxicity.

Alternative anti-tuberculosis regimen including ofloxacin for the treatment of patients with hepatic injury

SETTING

Tuberculosis (TB) clinic of a university-based public hospital in Rio de Janeiro city, Brazil.

OBJECTIVE

To describe treatment outcomes for TB patients with liver injury who received a 12-month regimen of ethambutol (E, EMB) and ofloxacin (O, OFL), including streptomycin (S, SM) for the first 3 months (3SEO/9EO) under routine clinical care conditions.

DESIGN

A retrospective study of a cohort of TB patients prescribed 3SEO/9EO was conducted over a 66-month period. Data were obtained by review of existing medical records. Primary outcomes assessed were cure, treatment failure, treatment default, TB relapse and death.

RESULTS

Outcomes were assessed for 40 patients with hepatic injury who met study criteria. Twenty-three (58%) were male and 13 (33%) were human immunodeficiency virus seropositive. Thirty-four (85%) patients were cured. Three patients (7.5%) defaulted from treatment, and three other patients died (7.5%). There were no treatment failures or relapses during 2 years of follow-up. Clinically recognized drug toxicity occurred in five patients (12.5%), and in each case was attributed to SM.

CONCLUSION

In this series of TB patients with serious liver injury, 3SEO/9EO was well-tolerated, and it was effective in 85% of patients when used under routine clinical care conditions.

Tuberculous sacro-ileitis: two cases and radiological findings

Infective sacro-ileitis is due to common bacteria, 25% being tuberculosis and 10% brucellosis. Slow progression characterizes joint tuberculosis, an uncommon variant of this disease. The onset is usually insidious, and early diagnosis requires a high index of clinical suspicion. We report two cases with tuberculous sacro-ileitis which initially mimicked brucellosis infiltration. Diagnosis of tuberculosis of the sacroiliac joint was established by fine-needle aspiration of joint and radiological imaging methods such as computerized tomography, magnetic resonance and three-phase bone scan. The current diagnosis and treatment of this condition is discussed based on these cases and a literature review.

Efficacy of DOTS strategy in treatment of respiratory tuberculosis in Gorgan, Islamic Republic of Iran

We carried out a follow-up cohort study of 260 smear-positive patients [178 on directly observed treatment, short-course (DOTS); 82 on non-DOTS] over a 2-year period to evaluate the efficacy of the DOTS strategy in treatment of tuberculosis (TB). All the patients had had cough for > 3 weeks; 91.9% had fever, 60.8% of them with sputum; and 27.7% had a positive family history. The rate of treatment failure with DOTS was 9.0% at the end of the 2nd month and 1.7% at the beginning of the 5th month. In the control group these rates were 18.3% and 7.3% respectively. The DOTS strategy significantly increased the success rate of TB treatment (P < 0.05).

Evaluation of a non-rifampicin continuation phase (6HE) following thrice-weekly intensive phase for the treatment of new sputum positive pulmonary tuberculosis

SETTING

Tuberculosis Research Centre, Chennai and Madurai, South India.

OBJECTIVE

To assess response to treatment, relapse and emergence of MDR TB in newly diagnosed patients with sputum-positive tuberculosis using an intermittent intensive phase followed by a non-rifampicin continuation phase.

DESIGN

Patients were treated in a controlled clinical trial with 2HRZE3/6HE with thrice-weekly direct dosing in the intensive phase and once-weekly with six doses self-administered in the continuation phase. Clinical and bacteriologic evaluation was done every month for 24 months.

RESULTS

The overall outcome was good, with 92% favourable response (cure) and 4.8% relapse in 450 patients including 103 who did not receive extension of intensive phase for positive smear, 38 with initial H-resistant cultures, 4 with MDR TB and 15 who received less than 75% of chemotherapy. In 392 patients with drug-susceptible cultures, 96%were cured and only 4% relapsed. There was no emergence of MDR TB among failures and relapses; toxicity was low.

CONCLUSION

Newly-diagnosed Category I patients can be effectively treated with this regimen without emergence of MDR TB. It has immense potential in programmes where directly observed therapy cannot be ensured throughout, and when rifampicin is contraindicated in HIV-TB patients who require concomitant therapy with anti-retroviral

[Perspective of pulmonary MAC infection treatment]

Chemotherapy of pulmonary MAC (Mycobacterium avium complex) infection has been almost universally agreed with the multidrugs regimen that contains Clarithromycin (CAM), Rifampin (RFP), Ethambtol (EB), and aminoglycoside in case of advanced stage. One of the reason for the multidrugs regimen which is similar to tuberculous chemotherapy is to inhibit the emersion of resistant MAC strain. The other reasons, enhancement of anti microbial activity and response to polyclonal infection are unique to the MAC chemotherapy. In the current MAC chemotherapy, both CAM and aminoglycoside are main axes because only they can suppress the growth of MAC alone respectively. Efficacy of CAM was revealed through the randomized controlled trials of disseminated MAC infection with HIV and that consequences applied to pulmonary MAC infection treatment. CAM is not effective unless exceed 2 microg/ml blood concentration. RFP decreases CAM blood concentration remarkably, but the regimens contained RFP and CAM are superior clinically to the regimens without RFP. There seemed to be unknown pharmacological mechanisms with RFP. Although the advantage of aminoglycosides is easily achieved high blood concentration, if aminoglycoside dosage is exceed 15 mg/kg, the possibility of auditory disturbance increase. About the duration of MAC chemotherapy, many guidelines recommended that one year continuation after the negative conversion of sputum culture. It is not the evidence but an expert opinion. We often experience recurrences several months later after the all drugs are ceased. The interval days to positive conversion of sputum culture from the day of completion of chemotherapy are randomly distributed with weibull's equation. It suggests that exogenous re-infection may cause the recurrence of pulmonary MAC infection as pointed out by Wallace Jr. Considering these issues, we have the conception of pulmonary MAC infection chemotherapy as follows. 1. Full dose induction chemotherapy (two years). 2. Maintenance chemotherapy (one year). 3. Preventive chemotherapy (one year). These conceptions have to be the problem validated. However, these current chemotherapies are not effective adequately, we need the combination treatment with surgical resection when indicated as a localized focus for example. Generally chemotherapy could not cured the destructed bronchial lesion due to MAC infection as like as local bronchiectasis or cavities. Consequently, the chemotherapy just after the surgical resection of destructed focus is most appropriate period.

Modification to improve efficiency of sampling schedules for BA/BE testing of FDC anti-tuberculosis drugs

SETTING

The assessment of rifampicin (RMP) containing fixed-dose combination (FDC) formulations using in vivo bioequivalence testing is widely accepted. It would be advantageous for both the drug regulatory authorities and drug manufacturers, for optimum minimum blood testing time intervals that encompass all anti-tuberculosis active constituents in the FDC to be established.

OBJECTIVE

To determine the optimum blood sampling schedule for testing novel FDC anti-tuberculosis drugs, isoniazid, RMP, pyrazinamide and ethambutol

DESIGN

The results of 12 different single-dose, two-way cross-over designs are presented. The studies determined the bioavailability and bioequivalence of RMP-containing FDCs, and conformed with the requirements of the South African national drug regulatory authority for each of the active constituents.

RESULTS

The pharmacokinetic parameters to determine bioavailability and the Hauschke method to determine bioequivalence revealed that a six-point time protocol, namely 0, 1, 2, 4, 6 and 8 h, provides a good approximation of the area under the curve, and that an 11-point time protocol of 0, 0.25, 0.5, 1, 1.5, 2, 2.5, 3, 4, 6 and 8 h provided information comparable to the conventional 15 time-points for FDCs containing up to four drugs.

CONCLUSION

The findings provide concrete economic benefit and convenience for quality assurance testing of existing and novel FDCs.

[A case of tuberculosis showing immune reconstitution syndrome after the initiation of antiretroviral therapy for HIV infection]

Abstract A 27-year-old man admitted for high fever, wet cough and abnormality on his chest radiograph. He was diagnosed as pulmonary tuberculosis, and started treatment with INH, RFP, EB, and PZA. After other examinations, he was diagnosed as having a acquired immunodeficiency syndrome, too. We gave him zidovudine and lamivudine/ abacavir sulfate to treat HIV infection. After starting treatment with anti-tuberculosis drugs his fever alleviated, but after 10 days from the start of anti-HIV drugs, he showed high fever, and abnormality of his chest radiograph exacervated. We diagnosed him as immune reconstitution syndrome, and gave him prednisolone 30 mg/day. His symptoms improved gradually.

Ethambutol dosage for the treatment of children: literature review and recommendations

The currently recommended daily dose of ethambutol (EMB) for the treatment of tuberculosis (TB) in children varies from a maximum daily dose of 15 mg/kg body weight daily (without a range) to 15-20 mg/kg and 20 mg/ kg (range 15-25 mg/kg). Published evidence relating to the dosage, toxicity and pharmacokinetics of EMB in children and adults is reviewed and a dose of EMB for use in childhood is recommended. Using key words 'ethambutol', 'childhood', 'TB', 'pharmacokinetics', 'bioavailability' and 'toxicity', Medline searches were conducted; cross-references were sought from original papers, books and conference proceedings dating from 1961. When English summaries were available, data were extracted from papers in languages other than English. EMB has a dose-related efficacy best seen when given to adults alone or with a single other drug. Together with isoniazid (INH), a dose of 15 mg/kg EMB gave better results than 6 mg/kg, and 25 mg/kg better than 15 mg/kg. The occurrence of ocular toxicity was also dose-related; >40% of adults developed toxicity at doses of >50 mg/ kg, and 0-3% at a dose of 15 mg/kg/daily. Peak serum EMB concentrations increase in relation to dose, but are significantly lower in children receiving the same dosage. In only 2 of 3811 children (0.05%) receiving EMB doses of 15-30 mg/kg was EMB stopped due to possible ocular toxicity; children of all ages can be given EMB in daily doses of 20 mg/kg (range 15-25 mg/kg) and three times weekly intermittent doses of 30 mg/kg body weight without undue concern.

Combination chemotherapy with the nitroimidazopyran PA-824 and first-line drugs in a murine model of tuberculosis

The creation of new chemotherapeutic regimens that permit shortening the duration of treatment is a major priority for antituberculosis drug development. In this study, we used the murine model of experimental tuberculosis therapy to determine whether incorporation of the investigational new nitroimidazopyran PA-824 into the standard first-line regimen has the potential to shorten the 6-month duration of treatment. As demonstrated previously, PA-824 alone had significant bactericidal activity over the first 2 months of treatment. Moreover, the substitution of PA-824 for isoniazid led to significantly lower lung CFU counts after 2 months of treatment and to more rapid culture-negative conversion compared to the standard regimen of rifampin, isoniazid, and pyrazinamide. Despite this, there was no difference in the proportion of mice relapsing after completing 6 months of therapy (2 of 19 mice treated with PA-824 in place of isoniazid relapsed versus 0 of 46 mice treated with the standard regimen). Meanwhile, no other PA-824-containing regimen tested was superior to the standard regimen on any assessment. Thus, we were unable to establish a clear role for PA-824 in a treatment-shortening regimen that includes two or more of the current first-line drugs. Future preclinical studies should include the evaluation of novel combinations of PA-824 with new drug candidates in addition to existing antituberculosis drugs for their potential to substantially improve the treatment of both drug-susceptible and multidrug-resistant tuberculosis.

The Expanding Spectrum of Mycobacterium avium Complex-Associated Pulmonary Disease

Nontuberculous mycobacteria (NTM) are increasingly recognized as important pulmonary pathogens. Mycobacterium avium intracellulare complex (MAC) causes most lung infections due to NTM. Patients with preexisting lung disease or immunodeficiency are at greatest risk for developing MAC infection. The majority of MAC pulmonary cases, however, occur in immunocompetent elderly women in association with nodular infiltrates and bronchiectasis. More recently, pulmonary disease has also been described in immunocompetent patients after exposure to MAC-contaminated hot tubs. We describe a case of aggressive MAC lung disease in a young immunocompetent female patient without preexisting lung disease whose clinical and pathologic characteristics do not fit into any of these categories and may represent a unique manifestation of MAC lung disease.

Impact of DOTS expansion on tuberculosis related outcomes and costs in Haiti

BACKGROUND

Implementation of the World Health Organization's DOTS strategy (Directly Observed Treatment Short-course therapy) can result in significant reduction in tuberculosis incidence. We estimated potential costs and benefits of DOTS expansion in Haiti from the government, and societal perspectives.

METHODS

Using decision analysis incorporating multiple Markov processes (Markov modelling), we compared expected tuberculosis morbidity, mortality and costs in Haiti with DOTS expansion to reach all of the country, and achieve WHO benchmarks, or if the current situation did not change. Probabilities of tuberculosis related outcomes were derived from the published literature. Government health expenditures, patient and family costs were measured in direct surveys in Haiti and expressed in 2003 US$.

RESULTS

Starting in 2003, DOTS expansion in Haiti is anticipated to cost $4.2 million and result in 63,080 fewer tuberculosis cases, 53,120 fewer tuberculosis deaths, and net societal savings of $131 million, over 20 years. Current government spending for tuberculosis is high, relative to the per capita income, and would be only slightly lower with DOTS. Societal savings would begin within 4 years, and would be substantial in all scenarios considered, including higher HIV seroprevalence or drug resistance, unchanged incidence following DOTS expansion, or doubling of initial and ongoing costs for DOTS expansion.

CONCLUSION

A modest investment for DOTS expansion in Haiti would provide considerable humanitarian benefit by reducing tuberculosis-related morbidity, mortality and costs for patients and their families. These benefits, together with projected minimal Haitian government savings, argue strongly for donor support for DOTS expansion.

Alginate nanoparticles as antituberculosis drug carriers: formulation development, pharmacokinetics and therapeutic potential

BACKGROUND

Reduction in the dosing frequency of antituberculosis drugs (ATDs) by applying drug delivery technology has the potential to improve the patient compliance in tuberculosis (TB). Alginate (a natural polymer) based nanoparticulate delivery system was developed for frontline ATDs (rifampicin, isoniazid, pyrazinamide and ethambutol).

METHODS

Alginate nanoparticles were prepared by the controlled cation induced gelification method and administered orally to mice. The drug levels were analysed by high performance liquid chromatography (HPLC) in plasma/tissues. The therapeutic efficacy was evaluated in M. tuberculosis H37Rv infected mice.

RESULTS

High drug encapsulation efficiency was achieved in alginate nanoparticles, ranging from 70%-90%. A single oral dose resulted in therapeutic drug concentrations in the plasma for 7-11 days and in the organs (lungs, liver and spleen) for 15 days. In comparison to free drugs (which were cleared from plasma/organs within 12-24 h), there was a significant enhancement in the relative bioavailability of encapsulated drugs. In TB-infected mice three oral doses of the formulation spaced 15 days apart resulted in complete bacterial clearance from the organs, compared to 45 conventional doses of orally administered free drugs.

CONCLUSIONS

Alginate nanoparticles appear to have the potential for intermittent therapy of TB.

[Treatment outcome of patients with multidrug-resistant pulmonary tuberculosis during pregnancy]

PURPOSE

To know the treatment outcome of patients with multidrug-resistant tuberculosis (MDR-TB) during gestation.

METHOD

Retrospective study of 3 cases of pregnant women, who were treated for MDR-TB with a regimen including pyrazinamide, ethambutol, para-aminosalicylic acid, cycloserine and amoxicillin-clavulanic acid.

RESULT

All patients showed a good response to anti-tuberculosis chemotherapy without any serious adverse effect, and were culture-negative at the time of delivery. Two patients delivered vaginally at weeks 40, and one patient delivered surgically at weeks 38. All newborns were healthy, and their tuberculin skin tests and placental tissue examinations were negative for tuberculosis.

CONCLUSION

MDR-TB can be successfully treated during pregnancy by using a regimen including effective second-line anti-tuberculosis drugs.

Factors Related to Response to Intermittent Treatment ofMycobacterium aviumComplex Lung Disease

RATIONALE

Mycobacterium avium complex pulmonary disease (MAC-PD) is associated with substantial morbidity, and standard daily multidrug therapy is difficult to tolerate.

OBJECTIVES

To characterize response to a three-times-weekly (TIW) regimen of clarithromycin, ethambutol, and rifampin.

METHODS

A 1-yr prospective noncomparative trial of TIW treatment was conducted during 2000-2003 in 17 U.S. cities. Participants were 91 HIV-negative adults, diagnosed with moderate to severe MAC-PD, who originally participated in a trial of an inhaled IFN-gamma treatment. Improvement in sputum culture, high-resolution computed tomography (HRCT), and symptoms were assessed.

RESULTS

Treatment response rates (and median response times) were 44% (2 mo or longer) for culture, 60% (5.5-11.5 mo) for HRCT, and 53% (8.5 mo) for symptoms. Having noncavitary, compared with cavitary, disease increased culture response by 4.0 times (95% confidence interval [CI], 1.7-9.2) and HRCT response by 4.9 times (95% CI, 1.9-13.0). Culture response was 1.5 times (95% CI, 1.1-2.2) higher for older subjects and 2.2 times (95% CI, 1.0-4.7) higher for previously untreated subjects. Being smear-negative increased culture response by 2.3 times (95% CI, 1.1-5.2) but decreased HRCT response by 4.4 times (95% CI, 1.7-11.5). Increasing ethambutol use by 5 mo increased culture response by 1.5 times (95% CI, 1.0-2.1) but decreased symptom response. Not having chronic obstructive pulmonary disease, bronchiectasis, or poor lung function increased symptom response by 1.9 to 3.9 times.

CONCLUSIONS

TIW therapy was less effective for MAC-PD patients with cavitary disease and a history of chronic obstructive pulmonary disease, bronchiectasis, or previous treatment for MAC-PD. Further research is needed to study the long-term outcomes of TIW treatment.

[A case of Mycobacterium intracellulare infection with chronic empyema]

A 83-year-old man had been treated for pulmonary infiltration was referred to a nearby hospital because of slight fever and cough. His chest radiograph and CT showed right chronic empyema, and in which pleural aspirate was smear positive for acid-fast bacilli and positive for PCR-Mycobacterium intracellulare. He was diagnosed as chronic empyema caused by M. intracellulare. A month later exacerbation of bronchopleural fistula was observed and M. intracellulare infection expanded into the lung. He was treated with combined use of ethambutol, rifampicin, clarithromycin, and streptomycin for six months, and his chest radiograph showed improvement, however, finally he died as he was in advanced age and emaciation due to chronic lung infection.

Bartonella quintana coinfection with Mycobacterium avium complex and CMV in an AIDS patient: case presentation

BACKGROUND

As a greater number of HIV-infected patients survive despite profound immunodepression due to medical progress, we face complex infection with multiple agents in AIDS-patients.

CASE PRESENTATION

We report the case of an AIDS patient with a primary clinical presentation suggestive of bacillary angiomatosis. We also found in cutaneous lesions Mycobacterium avium complex and cytomegalovirus.

CONCLUSION

This clinical case illustrates the possibility of multiple coinfections in AIDS patients and the need to be exhaustive in evaluating infectious diseases in severely immunocompromised patients.

Gene expression analysis using a modified HiCEP method applicable to prokaryotes: A study of the response of Rhodococcus to isoniazid and ethambutol

We established a novel method to analyze the gene expression of prokaryotes by modifying and optimizing the HiCEP (high coverage gene expression analysis) method, which was originally developed for eukaryotic gene expression profiling. Following the removal of abundant rRNA, the mRNA of prokaryotic cells was enzymatically polyadenylated and subjected to HiCEP analysis. This method was highly reproducible due to selective PCR that was performed by using adaptor specific primers. We confirmed induction of tipA and induction or suppression of cspA, which are genes that are obtained from distinctive actinomycetes and responded to thiostrepton and temperature stress, respectively. Further, we applied this method to explore the gene expression profile of Rhodococcus erythropolis in response to drugs that inhibit cell wall synthetic pathways, and we were able to identify 35 upregulated genes. Among these genes, we confirmed the upregulation of 22 genes by using RT-PCR (reverse transcriptase-polymerase chain reaction). Some of these genes are involved in the synthesis of mycolic acid and arabinogalactan, suggesting a cell response to drug treatment by regulation of the genes involved in cell wall synthesis. This method could prove to be a useful technique for gene expression analysis of prokaryotes, particularly nonmodel strains with unknown genome sequences.

Pharmacokinetic and pharmacodynamic behaviour of antitubercular drugs encapsulated in alginate nanoparticles at two doses

This study was designed to evaluate the pharmacokinetics and tissue distribution of free and alginate-encapsulated antitubercular drugs in mice at different doses. Alginate nanoparticles encapsulating isoniazid (INH), rifampicin (RIF), pyrazinamide (PZA) and ethambutol (EMB) were prepared by controlled cation-induced gelification of alginate. The formulation was orally administered to mice at two dose levels (D1 and D2). A comparison was made in mice receiving free drugs at equivalent doses. Drugs were analysed by high performance liquid chromatography (HPLC). The average size of alginate nanoparticles was found to be 235.5+/-0.0 nm with a polydispersity index of 0.44; drug encapsulation was 70-90% for INH and PZA, 80-90% for RIF and 88-95% for EMB. In the free drug groups, plasma levels of RIF and INH were higher and PZA and EMB levels were lower in the D1 group (per body surface area of mice) compared with the D2 group (recommended human dose). The plasma drug levels of all drugs were higher in the D1 encapsulated group compared with D2, resulting in higher values of area under the plasma drug concentration-time curve (AUC(0-infinity)). The relative bioavailabilities of all drugs encapsulated in alginate nanoparticles were significantly higher compared with free drugs. Drug levels were maintained at or above the minimum inhibitory concentration (MIC(90)) until Day 15 in organs after administration of encapsulated drugs, whilst free drugs stayed at or above the MIC(90) up to Day 1 only irrespective of dose. The levels of drugs in various organs remained above the MIC at both doses for equal periods, demonstrating their equiefficiency. Alginate nanoparticles hold great potential in reducing dosing frequency of antitubercular drugs.

[Tuberculosis of the submandibular gland: a case report]

INTRODUCTION

Tuberculosis remains an important public health problem in France. After a certain decline, its incidence has remained unchanged since 1990. 30% of tuberculosis cases are extra-pulmonary form, most of them concern nodes especially in cervical areas.

CASE REPORT

This case of submandibular tuberculosis illustrates diagnostic and therapeutic difficulties.

DISCUSSION

There are few clinical signs or laboratory clues suggestive of tuberculosis, however a surgery cannot be avoided and must be performed in combination with antituberculosis chemotherapy.

Neuropathie toxique induite par l’isoniazide : pensez à la prévention

INTRODUCTION

Antituberculous treatment is effective but has numerous side effects. Among these isoniazid induced neuropathy is easily preventable.

CASE REPORT

A female patient of 42 years, infected with HIV, presented with general deterioration associated with an interstitial pulmonary infiltrate and mediastinal lymphadenopathy. Tuberculosis was not confirmed bacteriologically but she responded to antituberculous treatment. Three months later she developed distal leg pains extending proximally. There was superficial sensory impairment up to the groins and loss of the ankle reflexes. The dose of isoniazid was reduced from 5 to 2.5 mg/kg/day on account of slow acetylator status and treatment with pyridoxine 250 mg/day commenced. The clinical signs resolved in a few weeks.

CONCLUSIONS

Isoniazid neuropathy develops in the presence of risk factors (HIV, alcoholism, diabetes, renal failure, malnutrition, pregnancy and lactation, neurotoxic medication) and manifests itself initially by burning feet. Pyridoxine is preventative in low dosage and curative in high dosage. The development of symptoms should lead to measurement of acetylator status, and a reduction of the isoniazid dose to 3 mg/kg/day or even less in slow acetylators.