Analysis of serum microRNA-122 in a randomized controlled trial of N-acetylcysteine for treatment of antituberculosis drug-induced liver injury

AIM

Serum microRNA-122 (miR-122) is a novel biomarker for drug-induced liver injury, with good sensitivity in the early diagnosis of paracetamol-induced liver injury. We describe miR-122 concentrations in participants with antituberculosis drug-induced liver injury (AT-DILI). We explored the relationship between miR-122 and alanine aminotransferase (ALT) concentrations and the effect of N-acetylcysteine (NAC) on miR-122 concentrations.

METHODS

We included participants from a randomized placebo-controlled trial of intravenous NAC in AT-DILI. ALT and miR-122 concentrations were quantified before and after infusion of NAC/placebo. We assessed correlations between ALT and miR-122 concentrations and described changes in ALT and miR-122 concentrations between sampling occasions.

RESULTS

We included 45 participants; mean age (± standard deviation) 38 (±10) years, 58% female and 91% HIV positive. The median (interquartile range) time between pre- and post-infusion biomarker specimens was 68 h (47-77 h). The median pre-infusion ALT and miR-122 concentrations were 420 U/L (238-580) and 0.58 pM (0.18-1.47), respectively. Pre-infusion ALT and miR-122 concentrations were correlated (Spearman's ρ = .54, P = .0001). Median fold-changes in ALT and miR-122 concentrations between sampling were 0.56 (0.43-0.69) and 0.75 (0.23-1.53), respectively, and were similar in the NAC and placebo groups (P = .40 and P = .68 respectively).

CONCLUSIONS

miR-122 concentrations in our participants with AT-DILI were considerably higher than previously reported in healthy volunteers and in patients on antituberculosis therapy without liver injury. We did not detect an effect of NAC on miR-122 concentrations. Further research is needed to determine the utility of miR-122 in the diagnosis and management of AT-DILI.

Four-Month Rifapentine Regimens with or without Moxifloxacin for Tuberculosis

BACKGROUND

Rifapentine-based regimens have potent antimycobacterial activity that may allow for a shorter course in patients with drug-susceptible pulmonary tuberculosis.

METHODS

In an open-label, phase 3, randomized, controlled trial involving persons with newly diagnosed pulmonary tuberculosis from 13 countries, we compared two 4-month rifapentine-based regimens with a standard 6-month regimen consisting of rifampin, isoniazid, pyrazinamide, and ethambutol (control) using a noninferiority margin of 6.6 percentage points. In one 4-month regimen, rifampin was replaced with rifapentine; in the other, rifampin was replaced with rifapentine and ethambutol with moxifloxacin. The primary efficacy outcome was survival free of tuberculosis at 12 months.

RESULTS

Among 2516 participants who had undergone randomization, 2343 had a culture positive for Mycobacterium tuberculosis that was not resistant to isoniazid, rifampin, or fluoroquinolones (microbiologically eligible population; 768 in the control group, 791 in the rifapentine-moxifloxacin group, and 784 in the rifapentine group), of whom 194 were coinfected with human immunodeficiency virus and 1703 had cavitation on chest radiography. A total of 2234 participants could be assessed for the primary outcome (assessable population; 726 in the control group, 756 in the rifapentine-moxifloxacin group, and 752 in the rifapentine group). Rifapentine with moxifloxacin was noninferior to the control in the microbiologically eligible population (15.5% vs. 14.6% had an unfavorable outcome; difference, 1.0 percentage point; 95% confidence interval [CI], -2.6 to 4.5) and in the assessable population (11.6% vs. 9.6%; difference, 2.0 percentage points; 95% CI, -1.1 to 5.1). Noninferiority was shown in the secondary and sensitivity analyses. Rifapentine without moxifloxacin was not shown to be noninferior to the control in either population (17.7% vs. 14.6% with an unfavorable outcome in the microbiologically eligible population; difference, 3.0 percentage points [95% CI, -0.6 to 6.6]; and 14.2% vs. 9.6% in the assessable population; difference, 4.4 percentage points [95% CI, 1.2 to 7.7]). Adverse events of grade 3 or higher occurred during the on-treatment period in 19.3% of participants in the control group, 18.8% in the rifapentine-moxifloxacin group, and 14.3% in the rifapentine group.

CONCLUSIONS

The efficacy of a 4-month rifapentine-based regimen containing moxifloxacin was noninferior to the standard 6-month regimen in the treatment of tuberculosis. (Funded by the Centers for Disease Control and Prevention and others; Study 31/A5349 ClinicalTrials.gov number, NCT02410772.).

Resistant hypertension during antituberculosis treatment: how is rifampicin implicated?

A 67-year-old mental institute resident was treated for smear-positive pulmonary tuberculosis. His background history included chronic essential hypertension which was well-controlled with amlodipine 10mg daily. However, his blood pressure became suboptimal one week into antitubercular treatment, necessitating escalation of antihypertensive therapy up to six medications. Following completion of antitubercular treatment, his blood pressure improved markedly. The number of antihypertensives was able to be reduced to only two after a month. We postulate that rifampicin has attenuated the therapeutic effect of amlodipine via potent induction of hepatic CYP3A4 but the failure to control the blood pressure even with medications unrelated to cytochrome P450 pathways raises the spectre of an additional interaction.

Efficacy of moxifloxacin combined with levofloxacin in the treatment of drug-resistant tuberculosis

Drug-resistant tuberculosis is a clinically common respiratory-borne chronic infectious disease. Fluoroquinolone drugs can inhibit the replication and transcription of bacterial DNA and cause bacteria to die, and the antibacterial spectrum of such drugs is broad, especially for Mycobacterium tuberculosis-induced diseases. This article observes and compares the clinical efficacy of levofloxacin and moxifloxacin in the treatment of multidrug-resistant tuberculosis (MDR-TB). At the end of the course of treatment, the treatment success rate was 76.4% in the control group and 68.2% in the treatment group. The difference between the two groups was not statistically significant (P<0.05). The cavity reduction rate was 70.1% in the control group and 62.5% in the treatment group. Adverse reaction rate, the control group was 14.7% and the treatment group was 18.1%. There was no significant difference between the two groups (P >0.05). For multidrug-resistant tuberculosis, levofloxacin tablets and moxifloxacin tablets have similar effects in the treatment of multidrug-resistant tuberculosis, adverse drug reactions, and economically difficult multidrug-resistant patients. Drug sensitivity indicates that they are sensitive to levofloxacin.

Forty-Year-Old Man With Abdominal Pain 4 Years Post-Renal Transplant: A Case Report

Tuberculosis (TB) is an opportunistic infection 20 to 74 times more frequent in immunocompromised patients compared to the general population. The prevalence with renal transplant had a 0.5% to 15% incidence. The infection could be pulmonary or extrapulmonary (EPTB). The EPTB accounts for almost 20% of TB cases in immunocompetent people and 50% in positive human immunodeficiency virus cases. In this case report, we present a patient who attended the emergency room because of chronic diarrhea, abdominal pain, loss of weight, nocturne diaphoresis, and intermittent fever. A computed tomography scan showed retroperitoneal ganglionic conglomeration. He got into an exploratory laparotomy for histopathology specimens and paraganglionic fluid culture to a Gene Xpert MTB-RIF Assay G4, positive for rifampicin resistance tuberculosis. After an individualized treatment, trying to protect the graft's remaining function, the patient returned with acute abdominal pain and pancreatic enzymes elevation; the antibiotic management had to be suspended until the return of renal function.

Cytokine-Mediated Systemic Adverse Drug Reactions in a Drug-Drug Interaction Study of Dolutegravir With Once-Weekly Isoniazid and Rifapentine

Background

Once-weekly isoniazid and rifapentine for 3 months is a treatment option in persons with human immunodeficiency virus and latent tuberculosis infection. This study aimed to examine pharmacokinetic drug-drug interactions between this regimen and dolutegravir, a first-line antiretroviral medication.

Methods

This was a single-center, open-label, fixed-sequence, drug-drug interaction study in healthy volunteers. Subjects received oral dolutegravir 50 mg once daily alone (days 1-4) and concomitantly with once-weekly isoniazid 900 mg, rifapentine 900 mg, and pyridoxine 50 mg (days 5-19). Dolutegravir concentrations were measured on days 4, 14, and 19, and rifapentine, 25-desacetyl-rifapentine, and isoniazid concentrations were measured on day 19. Cytokines and antidrug antibodies to isoniazid and rifapentine were examined at select time points.

Results

The study was terminated following the development of flu-like syndrome and elevated aminotransferase levels in 2 of 4 subjects after the third isoniazid-rifapentine dose. Markedly elevated levels of interferon-γ, CXCL10, C-reactive protein, and other cytokines were temporally associated with symptoms. Antidrug antibodies were infrequently detected. Dolutegravir area under the curve (AUC) was decreased by 46% (90% confidence interval, 27-110%; P = .13) on day 14. Rifapentine and 25-desacetyl rifapentine levels on day 19 were comparable to reference data, whereas isoniazid AUCs were approximately 67%-92% higher in the subjects who developed toxicities.

Conclusions

The combined use of dolutegravir with once-weekly isoniazid-rifapentine resulted in unexpected and serious toxicities that were mediated by endogenous cytokine release. Additional investigations are necessary to examine the safety and efficacy of coadministering these medications.

Clinical Trials Registration

NCT02771249.

Pharmacokinetics of adjusted-dose 8-hourly lopinavir/ritonavir in HIV-infected children co-treated with rifampicin

OBJECTIVES

To evaluate the proportion of children with lopinavir Cmin ≥1 mg/L when receiving a novel 8-hourly lopinavir/ritonavir dosing strategy during rifampicin co-treatment.

METHODS

HIV-infected children on lopinavir/ritonavir and rifampicin were enrolled in a prospective pharmacokinetic study. Children were switched from standard-of-care lopinavir/ritonavir-4:1 with additional ritonavir (1:1 ratio) twice daily to 8-hourly lopinavir/ritonavir-4:1 using weight-banded dosing. Rifampicin was dosed at 10-20 mg/kg/day. After 2 weeks, plasma samples were collected ∼2, 4, 6, 8 and 10 h after the morning lopinavir/ritonavir-4:1 dose, ALT was obtained to assess safety and treatment was switched back to standard of care. ClinicalTrials.gov registration number: NCT01637558.

RESULTS

We recruited 11 children in two weight bands: 5 (45%) were 10-13.9 kg and received 20-24 mg/kg/dose of lopinavir and 6 (55%) children weighed 6-9.9 kg and received 20-23 mg/kg/dose of lopinavir. The median age was 15 months (IQR = 12.6-28.8 months). The median (IQR) lopinavir Cmin was 3.0 (0.1-5.5) mg/L. Seven (63.6%) of the 11 children had Cmin values ≥1 mg/L. Children with a lopinavir mg/kg dose below the median 21.5 were more likely to have Cmin <1 mg/L (P = 0.02). There was a strong positive correlation between lopinavir and ritonavir concentrations. No associations were found between lopinavir AUC2-10 and age, sex, weight, nutritional status or mg/kg/dose of lopinavir.

CONCLUSIONS

These data do not support the use of 8-hourly lopinavir/ritonavir at studied doses. Evaluation of higher doses is needed to optimize treatment outcomes of TB and HIV in young children.

Linezolid for drug-resistant pulmonary tuberculosis

BACKGROUND

Linezolid was recently re-classified as a Group A drug by the World Health Organization (WHO) for treatment of multi-drug resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB), suggesting that it should be included in the regimen for all patients unless contraindicated. Linezolid use carries a considerable risk of toxicity, with the optimal dose and duration remaining unclear. Current guidelines are mainly based on evidence from observational non-comparative studies.

OBJECTIVES

To assess the efficacy of linezolid when used as part of a second-line regimen for treating people with MDR and XDR pulmonary tuberculosis, and to assess the prevalence and severity of adverse events associated with linezolid use in this patient group.

SEARCH METHODS

We searched the following databases: the Cochrane Infectious Diseases Specialized Register; CENTRAL; MEDLINE; Embase; and LILACS up to 13 July 2018. We also checked article reference lists and contacted researchers in the field.

SELECTION CRITERIA

We included studies in which some participants received linezolid, and others did not. We included randomized controlled trials (RCTs) of linezolid for MDR and XDR pulmonary tuberculosis to evaluate efficacy outcomes. We added non-randomized cohort studies to evaluate adverse events.Primary outcomes were all-cause and tuberculosis-associated death, treatment failure, and cure. Secondary outcomes were treatment interrupted, treatment completed, and time to sputum culture conversion. We recorded frequency of all and serious adverse events, adverse events leading to drug discontinuation or dose reduction, and adverse events attributed to linezolid, particularly neuropathy, anaemia, and thrombocytopenia.

DATA COLLECTION AND ANALYSIS

Two review authors (BS and DC) independently assessed the search results for eligibility and extracted data from included studies. All review authors assessed risk of bias using the Cochrane 'Risk of bias' tool for RCTs and the ROBINS-I tool for non-randomized studies. We contacted study authors for clarification and additional data when necessary.We were unable to perform a meta-analysis as one of the RCTs adopted a study design where participants in the study group received linezolid immediately and participants in the control group received linezolid after two months, and therefore there were no comparable data from this trial. We deemed meta-analysis of non-randomized study data inappropriate.

MAIN RESULTS

We identified three RCTs for inclusion. One of these studies had serious problems with allocation of the study drug and placebo, so we could not analyse data for intervention effect from it. The remaining two RCTs recruited 104 participants. One randomized 65 participants to receive linezolid or not, in addition to a background regimen; the other randomized 39 participants to addition of linezolid to a background regimen immediately, or after a delay of two months. We included 14 non-randomized cohort studies (two prospective, 12 retrospective), with a total of 1678 participants.Settings varied in terms of income and tuberculosis burden. One RCT and 7 out of 14 non-randomized studies commenced recruitment in or after 2009. All RCT participants and 38.7% of non-randomized participants were reported to have XDR-TB.Dosing and duration of linezolid in studies were variable and reported inconsistently. Daily doses ranged from 300 mg to 1200 mg; some studies had planned dose reduction for all participants after a set time, others had incompletely reported dose reductions for some participants, and most did not report numbers of participants receiving each dose. Mean or median duration of linezolid therapy was longer than 90 days in eight of the 14 non-randomized cohorts that reported this information.Duration of participant follow-up varied between RCTs. Only five out of 14 non-randomized studies reported follow-up duration.Both RCTs were at low risk of reporting bias and unclear risk of selection bias. One RCT was at high risk of performance and detection bias, and low risk for attrition bias, for all outcomes. The other RCT was at low risk of detection and attrition bias for the primary outcome, with unclear risk of detection and attrition bias for non-primary outcomes, and unclear risk of performance bias for all outcomes. Overall risk of bias for the non-randomized studies was critical for three studies, and serious for the remaining 11.One RCT reported higher cure (risk ratio (RR) 2.36, 95% confidence interval (CI) 1.13 to 4.90, very low-certainty evidence), lower failure (RR 0.26, 95% CI 0.10 to 0.70, very low-certainty evidence), and higher sputum culture conversion at 24 months (RR 2.10, 95% CI 1.30 to 3.40, very low-certainty evidence), amongst the linezolid-treated group than controls, with no differences in other primary and secondary outcomes. This study also found more anaemia (17/33 versus 2/32), nausea and vomiting, and neuropathy (14/33 versus 1/32) events amongst linezolid-receiving participants. Linezolid was discontinued early and permanently in two of 33 (6.1%) participants who received it.The other RCT reported higher sputum culture conversion four months after randomization (RR 2.26, 95% CI 1.19 to 4.28), amongst the group who received linezolid immediately compared to the group who had linezolid initiation delayed by two months. Linezolid was discontinued early and permanently in seven of 39 (17.9%) participants who received it.Linezolid discontinuation occurred in 22.6% (141/624; 11 studies), of participants in the non-randomized studies. Total, serious, and linezolid-attributed adverse events could not be summarized quantitatively or comparatively, due to incompleteness of data on duration of follow-up and numbers of participants experiencing events.

AUTHORS' CONCLUSIONS

We found some evidence of efficacy of linezolid for drug-resistant pulmonary tuberculosis from RCTs in participants with XDR-TB but adverse events and discontinuation of linezolid were common. Overall, there is a lack of comparative data on efficacy and safety. Serious risk of bias and heterogeneity in conducting and reporting non-randomized studies makes the existing, mostly retrospective, data difficult to interpret. Further prospective cohort studies or RCTs in high tuberculosis burden low-income and lower-middle-income countries would be useful to inform policymakers and clinicians of the efficacy and safety of linezolid as a component of drug-resistant TB treatment regimens.

Tuberculosis-HIV treatment with rifampicin or rifabutin: are the outcomes different?

BACKGROUND

Rifamycins are a group of antibiotics mainly used in the treatment of tuberculosis (TB), however they interact with antiretroviral therapy (ART). Rifabutin allows more regimens options for concomitant imunodeficiency virus (HIV) treatment compared to rifampicin.

OBJECTIVE

Compare the outcomes of TB-HIV co-infected patients who used rifampicin or rifabutin.

METHODS

We analysed data from a prospective cohort study at National Institute of Infectious Diseases Evandro Chagas, Rio de Janeiro (RJ), Brazil. Patients who were treated for TB and HIV with rifampicin or rifabutin, from February 2011 to September 2016 were included.

FINDINGS

There were 130 TB-HIV patients, of whom 102 were treated with rifampicin and 28 with rifabutin. All patients in the rifabutin-treated group and 55% of the rifampicin-treated group patients were ART-experienced. Patients treated with rifampicin had similar abandon and cure rates, interruptions in treatment due to adverse reactions, immune reconstitution inflammatory syndrome and a similar mortality rate as those treated with rifabutin. However, rifampicin-treated patients had higher CD4 counts and more frequently undetectable HIV viral load by the end of treatment (67% versus 18%, p < 0.001) compared to rifabutin-treated patients, even when only ART-experienced patients were evaluated (66,6% versus 36,3%, p = 0.039).

CONCLUSIONS

Patients who used rifabutin had worst immune and virological control. This group had more ART-experienced patients. New and simpler regimens are needed for patients who do not respond to previous antiretroviral therapies.

Forecasting Clinical Dose-Response From Preclinical Studies in Tuberculosis Research: Translational Predictions With Rifampicin

A crucial step for accelerating tuberculosis drug development is bridging the gap between preclinical and clinical trials. In this study, we developed a preclinical model-informed translational approach to predict drug effects across preclinical systems and early clinical trials using the in vitro-based Multistate Tuberculosis Pharmacometric (MTP) model using rifampicin as an example. The MTP model predicted rifampicin biomarker response observed in 1) a hollow-fiber infection model, 2) a murine study to determine pharmacokinetic/pharmacodynamic indices, and 3) several clinical phase IIa early bactericidal activity (EBA) studies. In addition, we predicted rifampicin biomarker response at high doses of up to 50 mg/kg, leading to an increased median EBA0-2 days (90% prediction interval) of 0.513 log CFU/mL/day (0.310; 0.701) compared to the standard dose of 10 mg/kg of 0.181 log/CFU/mL/day (0.076; 0.483). These results suggest that the translational approach could assist in the selection of drugs and doses in early-phase clinical tuberculosis trials.

Four Months of Rifampin or Nine Months of Isoniazid for Latent Tuberculosis in Adults

BACKGROUND

A 9-month regimen of isoniazid can prevent active tuberculosis in persons with latent tuberculosis infection. However, the regimen has been associated with poor adherence rates and with toxic effects.

METHODS

In an open-label trial conducted in nine countries, we randomly assigned adults with latent tuberculosis infection to receive treatment with a 4-month regimen of rifampin or a 9-month regimen of isoniazid for the prevention of confirmed active tuberculosis within 28 months after randomization. Noninferiority and potential superiority were assessed. Secondary outcomes included clinically diagnosed active tuberculosis, adverse events of grades 3 to 5, and completion of the treatment regimen. Outcomes were adjudicated by independent review panels.

RESULTS

Among the 3443 patients in the rifampin group, confirmed active tuberculosis developed in 4 and clinically diagnosed active tuberculosis developed in 4 during 7732 person-years of follow-up, as compared with 4 and 5 patients, respectively, among 3416 patients in the isoniazid group during 7652 person-years of follow-up. The rate differences (rifampin minus isoniazid) were less than 0.01 cases per 100 person-years (95% confidence interval [CI], -0.14 to 0.16) for confirmed active tuberculosis and less than 0.01 cases per 100 person-years (95% CI, -0.23 to 0.22) for confirmed or clinically diagnosed tuberculosis. The upper boundaries of the 95% confidence interval for the rate differences of the confirmed cases and for the confirmed or clinically diagnosed cases of tuberculosis were less than the prespecified noninferiority margin of 0.75 percentage points in cumulative incidence; the rifampin regimen was not superior to the isoniazid regimen. The difference in the treatment-completion rates was 15.1 percentage points (95% CI, 12.7 to 17.4). The rate differences for adverse events of grade 3 to 5 occurring within 146 days (120% of the 4-month planned duration of the rifampin regimen) were -1.1 percentage points (95% CI, -1.9 to -0.4) for all events and -1.2 percentage points (95% CI, -1.7 to -0.7) for hepatotoxic events.

CONCLUSIONS

The 4-month regimen of rifampin was not inferior to the 9-month regimen of isoniazid for the prevention of active tuberculosis and was associated with a higher rate of treatment completion and better safety. (Funded by the Canadian Institutes of Health Research and the Australian National Health and Medical Research Council; ClinicalTrials.gov number, NCT00931736 .).

Safety and Side Effects of Rifampin versus Isoniazid in Children

BACKGROUND

The treatment of latent infection with Mycobacterium tuberculosis is important in children because of their vulnerability to life-threatening forms of tuberculosis disease. The current standard treatment - 9 months of isoniazid - has been associated with poor adherence and toxic effects, which have hampered the effectiveness of the drug. In adults, treatment with 4 months of rifampin has been shown to be safer and to have higher completion rates than 9 months of isoniazid.

METHODS

In this multicenter, open-label trial, we randomly assigned 844 children (<18 years of age) with latent M. tuberculosis infection to receive either 4 months of rifampin or 9 months of isoniazid. The primary outcome was adverse events of grade 1 to 5 that resulted in the permanent discontinuation of a trial drug. Secondary outcomes were treatment adherence, side-effect profile, and efficacy. Independent review panels whose members were unaware of trial-group assignments adjudicated all adverse events and progression to active tuberculosis.

RESULTS

Of the children who underwent randomization, 829 were eligible for inclusion in the modified intention-to-treat analysis. A total of 360 of 422 children (85.3%) in the rifampin group completed per-protocol therapy, as compared with 311 of 407 (76.4%) in the isoniazid group (adjusted difference in the rates of treatment completion, 13.4 percentage points; 95% confidence interval [CI], 7.5 to 19.3). There were no significant between-group differences in the rates of adverse events, with fewer than 5% of the children in the combined groups with grade 1 or 2 adverse events that were deemed to be possibly related to a trial drug. Active tuberculosis, including 1 case with resistance to isoniazid, was diagnosed in 2 children in the isoniazid group during 542 person-years of follow-up, as compared with no cases in the rifampin group during 562 person-years (rate difference, -0.37 cases per 100 person-years; 95% CI, -0.88 to 0.14).

CONCLUSIONS

Among children under the age of 18 years, treatment with 4 months of rifampin had similar rates of safety and efficacy but a better rate of adherence than 9 months of treatment with isoniazid. (Funded by the Canadian Institutes of Health Research and Conselho Nacional de Pesquisa; ClinicalTrials.gov number, NCT00170209 .).

Mechanism Investigation of Rifampicin-Induced Liver Injury Using Comparative Toxicoproteomics in Mice

Tuberculosis is one of the top causes of death among curable infectious diseases; it is an airborne infectious disease that killed 1.1 million people worldwide in 2010. Anti-tuberculosis drug-induced liver injury is the primary cause of drug-induced liver injury (DILI). Rifampicin is one of the most common anti-tuberculosis therapies and has well-known hepatotoxicity. To understand the mechanism of rifampicin-induced liver injury, we performed a global proteomic analysis of liver proteins by LC-MS/MS in a mouse model after the oral administration of 177 and 442.5 mg/kg rifampicin (LD10 and LD25) for 14 days. Based on the biochemical parameters in the plasma after rifampicin treatment, the hepatotoxic effect of rifampicin in the mouse liver was defined as a mixed liver injury. In the present study, we identified 1101 proteins and quantified 1038 proteins. A total of 29 and 40 proteins were up-regulated and 27 and 118 proteins were down-regulated in response to 177 and 442.5 mg/kg rifampicin, respectively. Furthermore, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses to characterize the mechanism of rifampicin-induced hepatotoxicity. In the molecular function category, glutathione transferase activity was up-regulated and proteins related to arachidonic acid metabolism were down-regulated. In the KEGG pathway enrichment-based clustering analysis, the peroxisome proliferator-activated receptor-γ (PPARγ) signaling pathway, cytochrome P450, glutathione metabolism, chemical carcinogenesis, and related proteins increased dose-dependently in rifampicin-treated livers. Taken together, this study showed in-depth molecular mechanism of rifampicin-induced liver injury by comparative toxicoproteomics approach.

[PULMONARY TUBERCULOSIS AND TUBERCULOUS PLEURISY COMPLICATED WITH RIFAMPICIN-INDUCED HYPOTHYROIDISM: A CASE REPORT]

Rifampicin can induce hypothyroidism. We report a case of pulmonary tuberculosis and tuberculous pleurisy that was complicated by rifampicin-induced hypothyroidism. The patient received rifampicin-based tuberculosis treatment and experienced persistent appetite loss, which led us to pro- vide concomitant hypothyroidism treatment. An 85-year-old woman with no underlying thyroid-related disease presented to her local hospital with a 3-month history of appetite and weight loss. A chest radiograph revealed pleural effusions and infiltrative shadows in the lower fields of both lungs, and we also detected high levels of lympho- cytes and adenosine deaminase levels (49.6 IU/1) in the pleu- ral effusion, with positive results from a polymerase chain reaction assay of a sputum sample. Thus, we diagnosed the patient with pulmonary tuberculosis and tuberculous pleurisy, and initiated treatment using isoniazid, rifampicin, etham- butol, and pyrazinamide. Her clinical course was good and her anorexia was improved. However, she subsequently experienced recurrent appetite loss, malaise, and bilateral lower-leg edema. Follow-up laboratory testing revealed that she had developed hypothyroidism. We started treatment using levothyroxine without interrupting the tuberculosis treatment. The loss of appetite and other thyroid-related symptoms were improved. The patient's thyroid function had been normal at her admission, and there were no findings of Hashimoto's thyroiditis or other thyroid conditions. Based on the clinical course, we conclude that the rifampicin induced the hypothyroidism. Therefore, rifampicin-induced hypothyroidism should be considered in cases with persistent appetite loss, even if the patient appears to be experiencing anorexia as an adverse drug reaction.

Pharmacokinetics and safety/tolerability of higher oral and intravenous doses of rifampicin in adult tuberculous meningitis patients

High-dose intravenous (i.v.) rifampicin improved the outcome of tuberculous meningitis (TBM) in a previous study. Unfortunately, i.v. rifampicin is not available in many high-endemic settings. This study examined exposures to and safety of higher oral rifampicin doses compared with i.v. rifampicin. Thirty adult Indonesian TBM patients were randomised to rifampicin 750 mg (ca. 17 mg/kg) orally, 900 mg (ca. 20 mg/kg) orally or 600 mg (ca. 13 mg/kg, as used previously) i.v. over 1.5 h for 14 days, combined with other TB drugs. The pharmacokinetics of rifampicin was assessed in the critical phase of TBM treatment (≤3 days after treatment initiation) and at ≥9 days. In the first days of treatment, the geometric mean (range) plasma AUC0-24 values following rifampicin 750 mg orally, 900 mg orally and 600 mg i.v. were 131.4 (38.1-275.1), 164.8 (66.9-291.2) and 145.7 (77.7-430.2) mg⋅h/L, respectively; Cmax values were 14.3 (6.1-22.2), 16.2 (5.7-28.3) and 24.7 (13.9-37.8) mg/L. CSF concentrations correlated with plasma exposures. After ≥9 days, AUC0-24 values had decreased to 100.1, 101.2 and 94.9 mg⋅h/L. Transient grade 3 ALT increases (8/30 patients) and one grade 4 ALT increase occurred, not related to rifampicin exposure. Higher oral rifampicin doses resulted in approximately similar plasma AUC0-24 but lower plasma Cmax values compared with 600 mg i.v. over 1.5 h. Exposures to rifampicin varied substantially and decreased due to autoinduction. Liver function disturbances occurred in this severely ill population. Future studies should examine even higher rifampicin doses in TBM treatment.

Rifampcin-induced Thrombocytopaenia Purpura

We report the case of a 28-year-old resident doctor with no past history of having taken rifampicin, who presented with thrombocytoapaenic purpura occurring after the initiation of anti-tuberculosis therapy (isoniazid, rifampicin, pyrazinamide and ethambutol) for tubercular lymphadenopathy.

[[LIVER TOXICITY DUE TO RIFAMPICIN MONOTHERAPY IN LATENT TUBERCULOSIS INFECTION].]

To investigate the outcome of rifam- picin (RFP) monotherapy for latent tuberculosis infection (LTBI) and the incidence of RFP-induced liver toxicity. [Method] We conducted a retrospective chart review of patients who received RFP monotherapy as LTBI treatment at the Daiichi Dispensary Clinic. [Result] Of 61 patients who received RFP monotherapy, the treatment completion rate was 88.5%, self-termination rate was 3.3%, abandonment rate due to adverse drug effects was 8.2% (5 cases: 3 cases of skin eruption and 2 cases of liver dysfunction). Among the 2 cases of liver dysfunction, I was not associated with abnormal alkaline phosphatase (ALP) or gamma-glutamyl transferase (y GTP) levels. Among patients with liver dysfunction who did not discontinue RFP mono- therapy, no cases-of severely abnormal ALP and/or y GTP levels were reported. [Conclusion] The incidence of liver toxicity due to RFP is lower than that observed with isoniazid, and liver dysfunction due to RFP was not always associated with abnormal of ALP and/or yGTP levels.

Rifampin (INN Rifampicin)

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Rifampin use and safety in hospitalized infants

OBJECTIVE

This study aims to examine the use and safety of rifampin in the hospitalized infants.

STUDY DESIGN

Observational study of clinical and laboratory adverse events among infants exposed to rifampin from 348 neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2012.

RESULT

Overall, 2,500 infants received 4,279 courses of rifampin; mean gestational age was 27 weeks (5th, 95th percentile; 23, 36) and mean birth weight was 1,125 g (515; 2,830). Thrombocytopenia (121/1,000 infant days) and conjugated hyperbilirubinemia (25/1,000 infant days) were the most common laboratory adverse events. The most common clinical adverse events were medical necrotizing enterocolitis (64/2,500 infants, 3%) and seizure (60/2,500 infants, 2%).

CONCLUSION

The overall incidence of adverse events among infants receiving rifampin appears low; however, additional studies to further evaluate safety and dosing of rifampin in this population are needed.

Rifampicin-induced minimal change disease is improved after cessation of rifampicin without steroid therapy

There are several reports to demonstrate that rifampicin, a major anti-tuberculosis agent, is associated with some adverse renal effects, with a few cases of rifampicin-induced minimal change disease (MCD). In the present case, a 68-year-old female presented with nausea, vomiting, foamy urine, general weakness and edema. She had been taking rifampicin for 4 weeks due to pleural tuberculosis. The patient had no proteinuria before the anti-tuberculosis agents were started, but urine tests upon admission showed heavy proteinuria with a 24-h urinary protein of 9.2 g/day, and serum creatinine, albumin, and total cholesterol levels were 1.36 mg/dL, 2.40 g/dL, and 283 mg/dL, respectively. MCD was diagnosed, and the patient achieved complete remission after cessation of rifampicin without undergoing steroid therapy.

Randomized pharmacokinetic evaluation of different rifabutin doses in African HIV- infected tuberculosis patients on lopinavir/ritonavir-based antiretroviral therapy

BACKGROUND

Pharmacokinetic interactions between rifampicin and protease inhibitors (PIs) complicate the management of HIV-associated tuberculosis. Rifabutin is an alternative rifamycin, for patients requiring PIs. Recently some international guidelines have recommended a higher dose of rifabutin (150 mg daily) in combination with boosted lopinavir (LPV/r), than the previous dose of rifabutin (150 mg three times weekly {tiw}). But there are limited pharmacokinetic data evaluating the higher dose of rifabutin in combination with LPV/r. Sub-optimal dosing can lead to acquired rifamycin resistance (ARR). The plasma concentration of 25-O-desacetylrifabutin (d-RBT), the metabolite of rifabutin, increases in the presence of PIs and may lead to toxicity.

METHODS AND RESULTS

Sixteen patients with TB-HIV co-infection received rifabutin 300 mg QD in combination with tuberculosis chemotherapy (initially pyrazinamide, isoniazid and ethambutol then only isoniazid), and were then randomized to receive isoniazid and LPV/r based ART with rifabutin 150 mg tiw or rifabutin 150 mg daily. The rifabutin dose with ART was switched after 1 month. Serial rifabutin and d-RBT concentrations were measured after 4 weeks of each treatment. The median AUC0-48 and Cmax of rifabutin in patients taking 150 mg rifabutin tiw was significantly reduced compared to the other treatment arms. Geometric mean ratio (90% CI) for AUC0-48 and Cmax was 0.6 (0.5-0.7) and 0.5 (0.4-0.6) for RBT 150 mg tiw compared with RBT 300 mg and 0.4 (0.4-0.4) and 0.5 (0.5-0.6) for RBT 150 mg tiw compared with 150 mg daily. 86% of patients on the tiw rifabutin arm had an AUC0-24 < 4.5 μg.h/mL, which has previously been associated with acquired rifamycin resistance (ARR). Plasma d-RBT concentrations increased 5-fold with tiw rifabutin dosing and 15-fold with daily doses of rifabutin. Rifabutin was well tolerated at all doses and there were no grade 4 laboratory toxicities. One case of uveitis (grade 4), occurred in a patient taking rifabutin 300 mg daily prior to starting ART, and grade 3 neutropenia (asymptomatic) was reported in 4 patients. These events were not associated with increases in rifabutin or metabolite concentrations.

CONCLUSIONS

A daily 150 mg dose of rifabutin in combination with LPV/r safely maintained rifabutin plasma concentrations in line with those shown to prevent ARR.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00640887.

[Clinical experience using rifabutin for treating infection with Mycobacterium tuberculosis in elderly Japanese patients]

OBJECTIVES

To clarify whether rifabutin (RBT) can be used for treating tuberculosis in elderly Japanese patients in the clinical setting.

METHOD

We performed a clinical chart review from Oct 2008 to Dec 2011, for patients who were diagnosed with tuberculosis and were prescribed rifabutin, at the Fukujuji Hospital (180 beds for respiratory medicine, including 60 for TB). Primarily, we focused on characteristics of patients, the cause for RBT indication, and success rate of treatment.

RESULTS

During the study period, 1129 patients were diagnosed with tuberculosis, and among these, 42 (3.7%) patients were prescribed RBT. Of these, 39 patients were included in this study (3 were excluded because their prescription was terminated within 2 weeks because of reasons other than adverse effects). In all, 69% patients were male. Mean age was 69 years, and mean body mass index was 19.1 +/- 3.4 kg/m2. RFP-related adverse effects were observed in 28 patients (72%; age, 73 years); these included gastrointestinal complications in 16, liver dysfunction in 7, skin rashes in 6, and renal dysfunction and thrombocytopenia in 1 each). Additional medication was required in 6 patients, and RBT-resistant TB was noted in 5 patients (28%; age, 60 years). A success rate of 71.4% was observed in cases of RFP-related adverse effects, and that of 81.8% was observed in cases of other reasons. Except for the patient who experienced renal dysfunction, RBT could be used in all patients who experienced RFP-related adverse effects.

CONCLUSION

RBT showed a relatively good success rate, even in patients who experienced RFP-related adverse effects. Thus, RBT could be an alternative in cases of RFP-related adverse effects, even in elderly patients.

Pneumonitis induced by rifampicin: a case report and literature review

An 84-year-old woman being treated for miliary tuberculosis (TB) with rifampicin (RFP), isoniazid (INH), ethambutol (EB) and corticosteroids suffered from a persistent fever for five months. While tapering the dose of prednisolone, chest computed tomography (CT) revealed diffuse ground glass opacities (GGO) and bronchoalveolar lavage fluid (BALF) showed an increase in lymphocytes. After the anti-TB drugs were discontinued and the dose of the corticosteroids was increased, the CT findings and fever improved considerably. However, readministration of RFP provoked an inflammatory reaction, leading to a diagnosis of RFP-induced pneumonitis. This condition is very rare. This is the first report of RFP-induced pneumonitis occurring during adjunct steroid therapy.

Update on rifampin, rifabutin, and rifapentine drug interactions

BACKGROUND

Rifampin is a potent inducer of both cytochrome P-450 oxidative enzymes and the P-glycoprotein transport system. Among numerous well documented, clinically significant interactions, examples include warfarin, oral contraceptives, itraconazole, digoxin, verapamil, simvastatin, and human immunodeficiency virus-related protease inhibitors. Rifabutin reduces serum concentrations of antiretroviral agents, but less so than rifampin. Rifapentine is also an inducer of drug metabolism.

METHODS

A literature search of English language journals from 2008 to March 2012 was completed using several databases, including PubMed, EMBASE, and SCOPUS. Search terms included rifampin, rifabutin, rifapentine AND drug interactions.

FINDINGS

Examples of clinically relevant interactions with rifampin demonstrated by recent reports include posaconazole, voriconazole, oxycodone, risperidone, mirodenafil, and ebastine.

CONCLUSIONS

To avoid a reduced therapeutic response, therapeutic failure, or toxic reactions when rifampin, rifabutin, or rifapentine are added to or discontinued from medication regimens, clinicians need to be aware of these interactions. Recent studies have indicated that other transporter systems play a role in these drug interactions. As reports of rifampin drug interactions continue to grow, this review is a reminder to clinicians to be vigilant.

[A case of agranulocytosis caused by rifampicin during treatment of tuberculous lymphadenitis in a chronic renal failure patient]

A 52-year-old woman was admitted to our hospital because of intermittent high fever and chronic renal failure. Computed tomography of the thorax showed swelling of the paratracheal lymph nodes that was confirmed by gallium scintigraphy. Biopsy of the supraclavicular lymph node on the right side showed necrotizing lymphadenitis with Langhans giant cells surrounded by epithelioid cells. Anti-tuberculosis treatment, including isoniazid, rifampicin, ethambutol, and pyrazinamide was initiated. One month after treatment, the patient developed agranulocytosis (white blood cell [WBC], 2100 cells/microl; neutrophils, 5%) accompanied by severe diarrhea. Bone marrow histology showed poor development of granulocytes, but no atypical cells were observed. Therefore, rifampicin was discontinued, and treatment with granulocyte colony-stimulating factor (G-CSF) was initiated. Subsequently, the white blood cell count and the proportion of neutrophils increased to 12500 cells/microL and 80%, respectively. Rifampicin in the anti-tuberculosis chemotherapy regimen was replaced with levofloxacin. This is a rare case of agranulocytosis caused by rifampicin administered during anti-tuberculosis treatment in a chronic renal failure patient.

Coadministration of lopinavir/ritonavir and rifampicin in HIV and tuberculosis co-infected adults in South Africa

Background

In HIV-infected patients receiving rifampicin-based treatment for tuberculosis (TB), the dosage of lopinavir/ritonavir (LPV/r) is adjusted to prevent sub-therapeutic lopinavir concentrations. In this setting, South African clinicians were advised to administer super-boosted LPV/r (400 mg/400 mg) twice daily, instead of standard dosed LPV/r (400 mg/100 mg) twice daily. We sought to determine – in routine practice – the tolerability and HIV treatment outcomes associated with super-boosted LPV/r compared to unadjusted LPV/r in combination with rifampicin-based TB treatment.

Methodology/Principle Findings

We conducted a retrospective review of HIV-infected patients who receiving second-line ART with a LPV/r-containing regimen who required concomitant TB treatment. We identified 29 patients; the median age was 36 years (IQR 29–40), 22 (76%) were female, the median CD4 cell count and viral load at first-line ART failure was 86 cells/mm³ (IQR 21–159) and 39,457 copies/mL (IQR 6,025–157,500), respectively. According to physician preference, 15 (52%) of 29 patients received super-boosted LPV/r (400 mg/400 mg) every 12 hours during TB treatment and 14 (48%) of 29 patients received standard dose LPV/r (400 mg/100 mg) twice daily during TB treatment. Among patients who received super-boosted LPV/r there was a trend towards a higher rate of symptomatic transaminitis (27% vs. 7%; p = 0.3), gastrointestinal toxicity (20% vs. 0%; p = 0.2) and a significantly increased need for treatment discontinuation (47% vs. 7%; p = 0.035. The durability of coadministered treatment was significantly shorter in patients who received super-boosted lopinavir/ritonavir with TB treatment compared to patients who received standard lopinavir/ritonavir dosing (log rank, P = 0.036). The rate of virologic failure was not higher in patients with unadjusted LPV/r dosing.

Conclusions/Significance

We observed a high rate of toxicity and need for treatment discontinuation among patients on standard rifampicin-based TB treatment who received super-boosted LPV/r.

[A study of adverse drug reactions in the treatment of pulmonary Mycobacterium avium complex disease]

OBJECTIVES

Adverse drug reactions interfere with the standard treatment of pulmonary Mycobacterium avium complex (MAC) disease; however, few studies have investigated this issue. We studied adverse drug reactions in the treatment of pulmonary MAC disease.

SUBJECTS

We retrospectively examined 74 patients who underwent treatment for pulmonary MAC disease in our hospital between January 2001 and December 2009. These patients had received treatment with rifampicin, ethambutol (EB), and clarithromycin. We analyzed the adverse drug reactions seen in these patients.

RESULTS

Twenty-two patients developed one or more adverse drug reactions that led to treatment discontinuation or change in medication, whereas 52 patients did not experience any adverse reactions. The incidence rate of adverse reactions was 29.7%. The adverse drug reactions included visual impairment in 9 patients, liver function disorder in 2, skin eruption in 5, and fever in 5. In most of the cases, the standard treatment could not be continued.

DISCUSSION

Visual impairment associated with EB was the most common adverse drug reaction, and it led to the discontinuation of EB, and thus the standard treatment. Additionally, in case of other adverse drug reactions, it was difficult to find appropriate replacements for the causative drugs. Further investigations are required to establish a standard policy for the management of adverse drug reactions that can lead to the discontinuation of chemotherapy.

[Effect of combined therapy with melaxen on lipid peroxidation rate and citrate content in blood serum of patients with drug-induced hepatitis diagnosis]

A combined therapy with melaxen led to a decrease in the activity of gamma-glutamyl transpeptidase and the level of diene conjugates in blood serum of patients with the drug-induced hepatitis developing on the background of administration of antituberculous preparations. These changes are indicative of pronounced antioxidant and hepatoprotective properties of the drug. In addition, there was a decrease in the content of citrate and a change in the activity of aconitate hydratase toward a normal level, which reflects a decrease in the degree of pathologic oxidative stress development and is evidence of the antiradical effect of melaxen.

Pharmacogenetic & pharmacokinetic biomarker for efavirenz based ARV and rifampicin based anti-TB drug induced liver injury in TB-HIV infected patients

BACKGROUND

Implication of pharmacogenetic variations and efavirenz pharmacokinetics in concomitant efavirenz based antiviral therapy and anti-tubercular drug induced liver injury (DILI) has not been yet studied. We performed a prospective case-control association study to identify the incidence, pharmacogenetic, pharmacokinetic and biochemical predictors for anti-tubercular and antiretroviral drugs induced liver injury (DILI) in HIV and tuberculosis (TB) co-infected patients.

METHODS AND FINDINGS

Newly diagnosed treatment naïve TB-HIV co-infected patients (n = 353) were enrolled to receive efavirenz based ART and rifampicin based anti-TB therapy, and assessed clinically and biochemically for DILI up to 56 weeks. Quantification of plasma efavirenz and 8-hydroxyefaviernz levels and genotyping for NAT2, CYP2B6, CYP3A5, ABCB1, UGT2B7 and SLCO1B1 genes were done. The incidence of DILI and identification of predictors was evaluated using survival analysis and the Cox Proportional Hazards Model. The incidence of DILI was 30.0%, or 14.5 per 1000 person-week, and that of severe was 18.4%, or 7.49 per 1000 person-week. A statistically significant association of DILI with being of the female sex (p = 0.001), higher plasma efavirenz level (p = 0.009), efavirenz/8-hydroxyefavirenz ratio (p = 0.036), baseline AST (p = 0.022), ALT (p = 0.014), lower hemoglobin (p = 0.008), and serum albumin (p = 0.007), NAT2 slow-acetylator genotype (p = 0.039) and ABCB1 3435TT genotype (p = 0.001).

CONCLUSION

We report high incidence of anti-tubercular and antiretroviral DILI in Ethiopian patients. Between patient variability in systemic efavirenz exposure and pharmacogenetic variations in NAT2, CYP2B6 and ABCB1 genes determines susceptibility to DILI in TB-HIV co-infected patients. Close monitoring of plasma efavirenz level and liver enzymes during early therapy and/or genotyping practice in HIV clinics is recommended for early identification of patients at risk of DILI.

[Three cases of uveitis induced by mycobacteriosis therapy using rifabutin]

BACKGROUND

Rifabutin has been used clinically to combat tuberculosis as well as nontuberculosis Mycobacterium since 2008 in Japan. Uveitis associated with rifabutin is described in many reports, but none of these are of Japanese. We report three Japanese cases of nontuberculosis Mycobacterium with rifabutin-associated uveitis. CASE 1: A 91-year-old woman developed bilateral uveitis with hypopyon and vitreous opacity at 2 months after the initiation of rifabutin administration. The uveitis persisted regardless of topical administration of corticosteroids and the discontinuance of rifabutin. Her right eye required goniosynechiolysis in order to cure a secondary glaucoma, and the left eye required vitrectomy in order to cure vitreous inflammation. CASE 2: A 72-year-old woman developed uveitis in her right eye at 7 months after the initiation of rifabutin administration. Rifabutin was stopped two days after she presented, and the uveitis resolved quickly with topical administration of corticosteroids. CASE 3: An 83-year-old woman developed bilateral uveitis at 6 months after the initiation of rifabutin administration. The rifabutin was stopped two months after the initiation and the uveitis resolved with topical corticosteroids.

CONCLUSION

Rifabutin rarely causes uveitis as an ocular side effect. Early diagnosis and is important and reduction or discontinuance of the rifabutin as well as anti-inflammatory therapy need to be implemented when a patient develops this condition.

Hepatotoxicity in patients co-infected with tuberculosis and HIV-1 while receiving non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy and rifampicin-containing anti-tuberculosis regimen

To evaluate the rate of and risk factors for hepatotoxicity in tuberculosis (TB) and human immunodeficiency virus type 1 (HIV-1) co-infected patients while receiving non-nucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy (ART) and a rifampicin (RMP)-containing anti-TB regimen. We analyzed data from the N2R study which was an open label, randomized, comparative trial comparing treatment outcomes between 71 TB/HIV-1 co-infected patients receiving efavirenz (EFV)-based and nevirapine (NVP)-based ART; all of whom were receiving RMP-containing anti-TB treatment. Demographic data, liver function test, CD4 cell count, plasma HIV-1 RNA, hepatitis B surface antigen and anti-hepatitis C virus antibody were collected before initiating ART (week 0). Liver enzymes and total bilirubin levels were monitored at 6 weeks, 12 weeks and 24 weeks after ART initiation. All patients were followed until TB therapy was completed. Of 142 patients, 8 patients were excluded. Among the remaining 134 patients, the mean+/-SD age was 36.8+/-8.6 years and 67.2% were male. Severe hepatotoxicity (grade 3 or 4) developed in 4 patients (2.9%); 3 patients (4.6%) in the NVP group and 1 patient (1.4%) in the EFV group. Severe hyperbilirubinemia (grade 3 or 4) occurred in 7 patients (5.2%); 5 patients (7.7%) in the NVP group and 2 patients (2.9%) in the EFV group. Grade 1 or 2 hepatotoxicity occurred in 34 patients (31.4%). Hepatitis C virus co-infection (adjusted OR 3.03; 95%CI 1.26-7.29) was an independent risk factor associated with grade 1-4 hepatotoxicity (p=0.013). Monitoring of hepatotoxicity should be considered in TB/HIV-1 co-infected patients who are infected with HCV and receiving NVP.

[Pneumonitis induced by rifampicin]

An 86-year-old male with pulmonary tuberculosis developed fever, rash, and interstitial pneumonia 3 weeks after the beginning of treatment with isoniazid (INH), rifampicin (RFP), and ethambutol (EB). Chest CT showed new infiltration shadows that were diffuse bilateral ground-glass opacities mixed with dense consolidation and septal thickening, accompanied by a small amount of pleural effusion. Drug-induced pneumonitis was suspected, and therefore the antituberculous regimen was discontinued. The radiologic findings and symptoms improved promptly. A provocation trial with RFP lead to fever, diarrhea, and rash. Therefore, RFP was considered to be the causative drug. INH and EB were reintroduced without any recurrence of the symptoms. Clinicians should be aware not only of paradoxical reactions but also of drug-induced pneumonitis, when a new pulmonary infiltrate develops in the course of tuberculosis treatment.

Higher-dose rifampin for the treatment of pulmonary tuberculosis: a systematic review

OBJECTIVE

To provide a descriptive synthesis of the evidence assessing the efficacy and safety of higher doses of rifampin (RMP) for the treatment of pulmonary tuberculosis (TB).

METHODS

Systematic review of randomized controlled trials that evaluate a range of RMP doses, including doses higher than standard (>10 mg/kg or >600 mg), used as part of combination drug therapies for pulmonary TB. Two reviewers applied inclusion criteria, assessed trial quality and extracted data. Inclusion criteria were smear- or culture-confirmed pulmonary TB, and English and French language articles. Exclusion criteria were RMP monotherapy and smear-negative TB. Outcomes included were sputum culture conversion, treatment failure, recurrence and adverse events, including hepatotoxicity and flu-like syndrome.

RESULTS

Of 14 trials (4256 participants) identified, 12 were conducted before 1980. Four trials were considered high quality according to published guidelines. Study characteristics, including history of prior TB treatment, dose of RMP, duration of treatment, timing of introduction of intervention treatment, concomitant drugs, and duration of follow-up, varied, making synthesis of efficacy data challenging. Several trials suggested an advantage in terms of likelihood of culture conversion among patients receiving at least 900 mg RMP. However, an increased incidence of flu-like syndrome was seen when RMP doses of 900 mg and higher were given intermittently.

CONCLUSION

Historical trials suggest that higher than standard RMP dosing results in improved culture conversion rates. Phase 2 and 3 clinical trials evaluating higher doses of RMP and other rifamycins are needed to confirm efficacy and assure tolerability. Pharmacokinetic studies will be needed to inform the development of such trials.

Drug interaction between rifampicin and sirolimus in transplant patients

We report two cases of drug interaction between rifampicin and sirolimus in renal trans-plant patients who were diagnosed with tuberculosis after transplantation and induction of immuno-suppressive therapy with sirolimus. The dosage of sirolimus had to be increased, in one case up to six-fold and in the second case up to five-fold, to maintain serum levels after starting the rifampicin. The two patients tolerated the treatment well, with no signs of tuberculosis and good renal function.

[Rifabutin-associated hypopyon uveitis in patient with acquired immunodeficiency syndrome]

BACKGROUND

Rifabutin-associated uveitis has been recognized and established overseas, but there have been no reports of its occurance in Japan. We report a case of rifabutin-induced hypopyon uveitis in a patient with acquired immunodeficiency syndrome (AIDS).

CASE

A 45-year-old Filipino man with AIDS and pulmonary tuberculosis was on highly active antiretroviral therapy (HAART; lopinavir/ritonavir, zidovudine/lamivudine) and anti-tuberculosis therapy (isoniazid, rifabutin). At 11 weeks after starting rifabutin administration, unilateral acute uveitis with hypopyon developed, which progressed to bilateral uveitis by the following day. Funduscopic examination revealed no vitreo-retinal abnormalities. The uveitis resolved after discontinuation of the rifabutin and initiating topical corticosteroids and mydriatic therapy. No recurrence of the uveitis was noted during a 5-month follow-up period.

CONCLUSION

Rifabutin-associated uveitis with hypopyon should be considered as one possible causes of uveitis.

Outcomes and safety of concomitant nevirapine and rifampicin treatment under programme conditions in Malawi

SETTING

Thyolo District Hospital, rural Malawi.

OBJECTIVES

To report on 1) clinical, immunological and virological outcomes and 2) safety among human immunodeficiency virus (HIV) infected patients with tuberculosis (TB) who received concurrent nevirapine (NVP) and rifampicin (RMP) based treatment.

DESIGN

Retrospective cohort study.

METHODS

Analysis of programme data, June-December 2007.

RESULTS

Of a total of 156 HIV-infected TB patients who started NVP-based antiretroviral treatment, 136 (87%) completed TB treatment successfully, 16 (10%) died and 5 (4%) were transferred out. Mean body weight and CD4 gain (adults) were respectively 4.4 kg (95%CI 3.3-5.4) and 140 cells/mm(3) (95%CI 117-162). Seventy-four per cent of patients who completed TB treatment and had a viral load performed (n = 74) had undetectable levels (<50 copies/ml), while 17 (22%) had a viral load of 50-1000 copies/ml. Hepatotoxicity was present in 2 (1.3%) patients at baseline. Two patients developed Grade 2 and one developed Grade 3 alanine transaminase enzyme elevations during TB treatment (incidence rate per 10 years of follow-up 4.2, 95%CI 1.4-13.1). There were no reported deaths linked to hepatotoxicity.

CONCLUSIONS

In a rural district in Malawi, concomitant NVP and RMP treatment is associated with good TB treatment outcomes and appears safe. Further follow-up of patients would be useful to ascertain the longer-term effects of this concurrent treatment.

Rifabutin-Associated Panuveitis with Retinal Vasculitis in Pulmonary Tuberculosis

INTRODUCTION

Rifabutin-associated uveitis has been reported frequently in AIDS patients and more rarely in immunocompetent patients. It is characterized clinically by anterior acute uveitis. Only a few poorly documented cases of rifabutin-induced panuveitis with retinal vasculitis have been reported. Here, we report four cases of rifabutin-associated panuveitis with retinal vasculitis.

CASE REPORTS

We describe four patients with active tuberculosis, treated with a multidrug regimen including rifabutin for at least 1.5 months before presentation. The first patient was immunocompetent, the three others had AIDS and were undergoing triple anti-HIV therapy. Three patients were women with a low body weight. All four patients presented with panuveitis and retinal vasculitis. Interruption of the drug rapidly reduced the ocular inflammation in all cases.

CONCLUSION

Four cases of rifabutin-associated panuveitis with retinal vasculitis are reported in patients with active pulmonary tuberculosis. Immunogenicity of Mycobacterium tuberculosis as well as the very low weight of the patients might be implicated in the development of this unusual form of rifabutin-associated uveitis.