| 2020 | Telacebec (Q203)-containing intermittent oral regimens sterilized mice infected with Mycobacterium ulcerans after only 16 doses. | PLoS Negl Trop Dis | Buruli ulcer (BU), caused by Mycobacterium ulcerans, is currently treated with a daily combination of rifampin and either injectable Streptomycin or oral clarithromycin. An intermittent oral regimen would facilitate treatment supervision. We first evaluated the bactericidal activity of newer antimicrobials against M. ulcerans using a BU animal model. The imidazopyridine amine telacebec (Q203) exhibited high bactericidal activity whereas tedizolid (an oxazolidinone closely related to linezolid), selamectin and ivermectin (two avermectine compounds) and the benzothiazinone PBTZ169 were not active. Consequently, telacebec was evaluated for its bactericidal and sterilizing activities in combined intermittent regimens. Telacebec given twice a week in combination with a long-half-life compound, either rifapentine or bedaquiline, sterilized mouse footpads in 8 weeks, i.e. after a total of only 16 doses, and prevented relapse during a period of 20 weeks after the end of treatment. These results are very promising for future intermittent oral regimens which would greatly simplify BU treatment in the field. |
| 2019 | Shortening Buruli Ulcer Treatment with Combination Therapy Targeting the Respiratory Chain and Exploiting Mycobacterium ulcerans Gene Decay. | Antimicrob Agents Chemother | Buruli ulcer is treatable with antibiotics. An 8-week course of rifampin (RIF) and either Streptomycin (STR) or clarithromycin (CLR) cures over 90% of patients. However, STR requires injections and may be toxic, and CLR shares an adverse drug-drug interaction with RIF and may be poorly tolerated. Studies in a mouse footpad infection model showed that increasing the dose of RIF or using the long-acting rifamycin rifapentine (RPT), in combination with clofazimine (CFZ), a relatively well-tolerated antibiotic, can shorten treatment to 4 weeks. CFZ is reduced by a component of the electron transport chain (ETC) to produce reactive oxygen species toxic to bacteria. Synergistic activity of CFZ with other ETC-targeting drugs, the ATP synthase inhibitor bedaquiline (BDQ) and the : oxidase inhibitor Q203 (now named telacebec), was recently described against Recognizing that mutants lacking the alternative oxidase are hypersusceptible to Q203 and that is a natural oxidase-deficient mutant, we tested the susceptibility of to Q203 and evaluated the treatment-shortening potential of novel 3- and 4-drug regimens combining RPT, CFZ, Q203, and/or BDQ in a mouse footpad model. The MIC of Q203 was extremely low (0.000075 to 0.00015 μg/ml). Footpad swelling decreased more rapidly in mice treated with Q203-containing regimens than in mice treated with RIF and STR (RIF+STR) and RPT and CFZ (RPT+CFZ). Nearly all footpads were culture negative after only 2 weeks of treatment with regimens containing RPT, CFZ, and Q203. No relapse was detected after only 2 weeks of treatment in mice treated with any of the Q203-containing regimens. In contrast, 15% of mice receiving RIF+STR for 4 weeks relapsed. We conclude that it may be possible to cure patients with Buruli ulcer in 14 days or less using Q203-containing regimens rather than currently recommended 56-day regimens. |
| 2019 | High-Dose Rifamycins Enable Shorter Oral Treatment in a Murine Model of Mycobacterium ulcerans Disease. | Antimicrob Agents Chemother | Buruli ulcer (BU), caused by , is a neglected tropical skin and soft tissue infection that is associated with disability and social stigma. The mainstay of BU treatment is an 8-week course of rifampin (RIF) at 10 mg/kg of body weight and 150 mg/kg Streptomycin (STR). Recently, the injectable STR has been shown to be replaceable with oral clarithromycin (CLR) for smaller lesions for the last 4 weeks of treatment. A shorter, all-oral, highly efficient regimen for BU is needed, as the long treatment duration and indirect costs currently burden patients and health systems. Increasing the dose of RIF or replacing it with the more potent rifamycin drug rifapentine (RPT) could provide such a regimen. Here, we performed a dose-ranging experiment of RIF and RPT in combination with CLR over 4 weeks of treatment in a mouse model of disease. A clear dose-dependent effect of RIF on both clinical and microbiological outcomes was found, with no ceiling effect observed with tested doses up to 40 mg/kg. RPT-containing regimens were more effective on All RPT-containing regimens achieved culture negativity after only 4 weeks, while only the regimen with the highest RIF dose (40 mg/kg) did so. We conclude that there is dose-dependent efficacy of both RIF and RPT and that a ceiling effect is not reached with the current standard regimen used in the clinic. A regimen based on higher rifamycin doses than are currently being evaluated against tuberculosis in clinical trials could shorten and improve therapy of Buruli ulcer. |
| 2016 | Sterilizing Activity of Fully Oral Intermittent Regimens against Mycobacterium Ulcerans Infection in Mice. | PLoS Negl Trop Dis | The treatment of Buruli ulcer (BU) that is caused by Mycobacterium ulcerans, is currently based on a daily administration of rifampin and Streptomycin (RIF-STR). A fully oral intermittent regimen would greatly simplify its treatment on the field.The objective of this study was to assess the bactericidal and sterilizing activities of intermittent oral regimens in a murine model of established M. ulcerans infection. Regimens combining rifapentine (RFP 20 mg/kg) with either moxifloxacin (MXF 200 mg/kg), clarithromycin (CLR 100 mg/kg) or bedaquiline (BDQ 25 mg/kg) were administrated twice (2/7) or three (only for RFP-CLR 3/7) times weekly during 8 weeks. The bactericidal but also the sterilizing activities of these four intermittent oral regimens were at least as good as those obtained with control weekdays regimens, i.e. RFP-CLR 5/7 or RIF-STR 5/7. A single mouse from the RFP-MFX 2/7 group had culture-positive relapse at the end of the 28 weeks following treatment completion among the 157 mice treated with one of the four intermittent regimens (40 RFP-CLR 2/7, 39 RFP-CLR 3/7, 39 RFP-MXF 2/7, 39 RFP-BDQ 2/7).These results open the door for a fully intermittent oral drug regimen for BU treatment avoiding intramuscular injections and facilitating supervision by health care workers. |
| 2016 | Characterization of 22 Antituberculosis Drugs for Inhibitory Interaction Potential on Organic Anionic Transporter Polypeptide (OATP)-Mediated Uptake. | Antimicrob Agents Chemother | We investigated the inhibitory interaction potential of 22 currently marketed antituberculosis (TB) drugs on organic anion-transporting polypeptide 1B1 (OATP1B1)-, OATP2B1-, and OATP1B3-mediated uptake using in vitro Xenopus oocytes and HEK cells. Rifabutin, ethambutol, amoxicillin, linezolid, p-amino salicylic acid, and rifapentine exhibited mild to moderate inhibitory effects on OATP-mediated uptake of estrone-3 sulfate, estradiol 17β-d-glucuronide, and rosuvastatin. The 50% inhibitory concentration (IC50) values of rifabutin, amoxicillin, ethambutol, p-amino salicylic acid, and linezolid were 35.4, 36.2, 57.6, 72.6, and 65.9 μM, respectively, for uptake mediated by organic anionic transporter polypeptide 1B1 (OATP1B1) and 28.8, 28.9, 53.9, 31.5, and 61.0 μM, respectively, for uptake mediated by organic anionic transporter polypeptide 1B3 (OATP1B3). Streptomycin and linezolid showed greater inhibition of organic anionic transporter polypeptide 2B1 (OATP2B1)-mediated uptake, with IC50 values of 33.2 and 35.6 μM, respectively, along with mild inhibition of other drugs. Furthermore, rifabutin, amoxicillin, and rifapentine significantly inhibited OATP1B1-mediated rosuvastatin uptake, with IC50 values of 12.3, 13.0, and 11.0 μM, respectively, which showed a similar profile to estrone-3 sulfate uptake. The calculated R values ([I]u inlet,max/Ki, where [I]u inlet,max represents the maximum estimated inhibitor concentration inlet to the liver and Ki is the inhibition constant) as the drug-drug interaction (DDI) indexes of PAS, ethambutol, and amoxicillin were 26.1, 6.5, and 4.3 for OATP1B1 and 52.0, 8.0, and 4.6 for OATP1B3, and those for Streptomycin, amikacin, and linezolid were 5.0, 4.2, and 4.4 for OATP2B1, respectively, suggesting a higher possibility of in vivo DDIs. This study is the first comprehensive report to show the novel inhibitory potential of 22 marketed anti-TB drugs on OATP-mediated uptake, providing evidence for future in vivo clinical DDI studies. |
| 2013 | Bactericidal activity does not predict sterilizing activity: the case of rifapentine in the murine model of Mycobacterium ulcerans disease. | PLoS Negl Trop Dis | Since 2004, treatment of Mycobacterium ulcerans disease, or Buruli ulcer, has shifted from surgery to daily treatment with Streptomycin (STR) + rifampin (RIF) for 8 weeks. For shortening treatment duration, we tested the potential of daily rifapentine (RPT), a long-acting rifamycin derivative, as a substitute for RIF.BALB/c mice were infected with M. ulcerans in the right hind footpad and treated either daily (7/7) with STR+RIF or five days/week (5/7) with STR+RIF or STR+RPT for 4 weeks, beginning 28 days after infection when CFU counts were 4.88±0.51. The relative efficacy of the drug treatments was compared by footpad CFU counts during treatment and median time to footpad swelling after treatment cessation as measure of sterilizing activity. All drug treatments were bactericidal. After 1 week of treatment, the decline in CFU counts was significantly greater in treated mice but not different between the three treated groups. After 2 weeks of treatment, the decline in CFU was greater in mice treated with STR+RPT 5/7 than in mice treated with STR+RIF 7/7 and STR+RIF 5/7. After 3 and 4 weeks of treatment, CFU counts were nil in mice treated with STR+RPT and reduced by more than 3 and 4 logs in mice treated with STR+RIF 5/7 and STR+RIF 7/7, respectively. In sharp contrast to the bactericidal activity, the sterilizing activity was not different between all drug regimens although it was in proportion to the treatment duration.The better bactericidal activity of daily STR+RIF and especially of STR+RPT did not translate into better prevention of relapse, possibly because relapse-freecure after treatment of Buruli ulcer is more related to the reversal of mycolactone-induced local immunodeficiency by drug treatment rather than to the bactericidal potency of drugs. |
| 2012 | Streptomycin-starved Mycobacterium tuberculosis 18b, a drug discovery tool for latent tuberculosis. | Antimicrob Agents Chemother | Mycobacterium tuberculosis 18b, a Streptomycin (STR)-dependent mutant that enters a viable but nonreplicating state in the absence of STR, has been developed as a simple model for drug testing against dormant bacilli. Here, we further evaluated the STR-starved 18b (SS18b) model both in vitro and in vivo by comparing the behavior of 22 approved and experimental tuberculosis drugs. Using the resazurin reduction microplate assay (REMA), rifampin (RIF), rifapentine (RPT), TMC207, clofazimine (CFM), and linezolid (LIN) were found to be active against SS18b in vitro, and their bactericidal activity was confirmed by determining the number of CFU. A latent 18b infection was established in mice, and some of the above-mentioned drugs were used for treatment, either alone or in combination with RIF. RIF, RPT, TMC207, CFM, and pyrazinamide (PZA) were all active in vivo, while cell wall inhibitors were not. A comparative kinetic study of rifamycin efficacy was then undertaken, and the results indicated that RPT clears latent 18b infection in mice faster than RIF. Intrigued by the opposing responses of live and dormant 18b cells to cell wall inhibitors, we conducted a systematic analysis of 14 such inhibitors using REMA. This uncovered an SS18b signature (CWPRED) that accurately predicted the activities of cell wall inhibitors and performed well in a blind study. CWPRED will be useful for establishing the mode of action of compounds with unknown targets, while the SS18b system should facilitate the discovery of drugs for treating latent tuberculosis. |
| 2011 | Activities of rifampin, Rifapentine and clarithromycin alone and in combination against mycobacterium ulcerans disease in mice. | PLoS Negl Trop Dis | treatment of Mycobacterium ulcerans disease, or Buruli ulcer (BU), has shifted from surgery to treatment with Streptomycin(STR)+rifampin(RIF) since 2004 based on studies in a mouse model and clinical trials. We tested two entirely oral regimens for BU treatment, rifampin(RIF)+clarithromycin(CLR) and rifapentine(RPT)+clarithromycin(CLR) in the mouse model.BALB/c mice were infected in the right hind footpad with M. ulcerans strain 1059 and treated daily (5 days/week) for 4 weeks, beginning 11 days after infection. Treatment groups included an untreated control, STR+RIF as a positive control, and test regimens of RIF, RPT, STR and CLR given alone and the RIF+CLR and RPT+CLR combinations. The relative efficacy of the drug treatments was compared on the basis of footpad CFU counts and median time to footpad swelling. Except for CLR, which was bacteriostatic, treatment with all other drugs reduced CFU counts by approximately 2 or 3 log(10). Median time to footpad swelling after infection was 5.5, 16, 17, 23.5 and 36.5 weeks in mice receiving no treatment, CLR alone, RIF+CLR, RIF alone, and STR alone, respectively. At the end of follow-up, 39 weeks after infection, only 48%, 26.4% and 16.3% of mice treated with RPT+CLR, RPT alone and STR+RIF had developed swollen footpads. An in vitro checkerboard assay showed the interaction of CLR and RIF to be indifferent. However, in mice, co-administration with CLR resulted in a roughly 25% decrease in the maximal serum concentration (Cmax) and area under the serum concentration-time curve (AUC) of each rifamycin. Delaying the administration of CLR by one hour restored Cmax and AUC values of RIF to levels obtained with RIF alone.these results suggest that an entirely oral daily regimen of RPT+CLR may be at least as effective as the currently recommended combination of injected STR+oral RIF. |
| 2010 | [Therapeutic efficacy of drug susceptibility test-guided individualized anti-tuberculosis chemotherapy for spinal tuberculosis]. | Zhonghua Wai Ke Za Zhi | To investigate the efficacy of individualized anti-tuberculosis chemotherapy guided by drug susceptibility testing for spinal tuberculosis through analyses on the post-operative follow-up outcomes.The diagnoses of spinal tuberculosis were established by clinical, radiological and histological evaluation in 132 patients who were admitted from August 2005 to January 2010, 62 patients (37 male and 25 female) with follow-up more than 12 months in this study. The average age was 33.6 years (ranging from 4 - 67 years). The infected samples were collected during surgery. After processed in a routine laboratory procedure, the samples were inoculated into vials of the BACT/ALERT 3D system. The drug susceptibility testing was performed using absolute concentration method, which included 11 first-line and second-line drugs. Four or five anti-tuberculosis drug regimen was chosen according to the results of drug susceptibility testing. All the patients were followed up a month later, and then once 3 months in the following 11 months, and subsequently at intervals of half a year. The clinical status, erythrocyte sedimentation rate (ESR), roentgenogram, MRI and 3D-CT were concerned to estimate the progress of tuberculosis.The culture positive rate was 45.2% (28/62). The average detection time was 42 d (ranging from 28 - 58 d). The drug susceptibility testing showed a total drug resistance level of 24.2%:12.9% for isoniazid, 4.8% for rifampicin, 3.2% for ethambutol, 9.7% for Streptomycin, 6.4% for pasiniazid, 14.5% for levofloxacin, 1.6% for rifapentine. The mean follow-up period was 21 months (ranging from 12 - 44 months). According to Bridwell criteria, grade I bony fusion was obtained in all patients in 8 - 12 months.Guided by drug susceptibility testing, individualized anti-tuberculosis chemotherapy for 12 to 18 months is effective for spinal tuberculosis. |
| 2010 | Neglected diseases caused by bacterial infections. | Curr Med Chem | Bacterial infections represent a major health problem, especially in third world countries. In endemic regions, large populations of people are greatly affected, but the medical care is very limited. In this review, the neglected diseases buruli ulcer and trachoma are elucidated. Buruli ulcer is caused by Mycobacterium ulcerans which produces an outstanding immunosuppressive toxin mycolactone that induces an ulcerative, necrotic skin disease. Until today, only the combination of rifampin/Streptomycin is used to treat buruli ulcer. However, this therapy is ineffective and expensive. Here, we report new findings that suggest pharmaceutical formulations such as rifapentine, in combination with clarithromycin or moxifloxacin that have shown promising results in mice footpad trials. Moreover, alternative treatment options such as heat therapy, nitric oxide cremes and French clay show bactericidal effects. The genotyping of M. ulcerans also promises new ways of finding drug targets and vaccines. Trachoma, induced by the bacterium Chlamydia trachomatis, is the primary infectious cause of blindness worldwide. Recurrent infections lead to chronic inflammation of the upper tarsal conjunctiva. As a consequence, scarring and distortion of the eye lids occur, eventually resulting in blindness. First-line medications for trachoma treatment are bacteriostatic agents such as topically applied tetracylines and systematically administered azithromycin. Surgery, environmental improvements and personal hygiene are further crucial factors in controlling trachoma. Moreover, efforts are being undertaken towards the development of vaccine systems, with the major outer membrane protein and the polymorphic membrane protein acting as attractive candidates. |
| 2008 | [Effects of two treatment regimens for drug-resistant tuberculosis in tuberculosis control project areas: a comparative study]. | Zhonghua Yi Xue Za Zhi | To search for an ideal therapeutic regimen for multidrug resistant tuberculosis conforming to the situation of China.One hundred and fifty-four patients with rifampin-resistant tuberculosis, 114 multi-drug resistant (MDR-TB) and 40 resistant to other drugs, in Heilongjiang, Zhejiang, and Shenzhen, 107 males and 47 females, aged 39 (19-77), were randomly divided into 2 groups: 85 patients in the group of drug-resistant regimen, 3RFT AM Ofx Pto PAS-INH/5RFT Ofx Pto PAS-INH regimen, including rifapentine (RFT), amikacin (Am), ofloxacin (Ofx), protionamide (Pto), para-aminosalicylic acid-isoniazid (PAS-INH) for 3 months and then RFT, Ofx, Pto, and PAS-INH for 5 months, and 69 in the retreatment regimen group undergoing 3 H3R3Z3E3S3/5 H3R3E3, including isoniazid (H), rifampin (R), pyrazinamide (Z), ethambutol (E), and Streptomycin (S) for 3 months and then H, R, and E for 5 months. Sputum smear was checked and the sputum smear conversion rate was calculated as an effective treatment indicator 3, 6, and 8 months later.One hundred and fourteen of the 154 patients were treated for a good 8 months. The sputum smear conversion rate 8 months after treatment of the drug-resistant regimen group was 65.9% (56/85), significantly higher than that of the retreatment regimen group [40.6% (28/69), chi2 = 9.834, P = 0.002]. Eighty-five of the 114 MDR-TB patients had been treated for a good 8 months with a sputum smear conversion rate of 61.8% (42/68), significantly higher than that of the retreatment regimen group [39.1% (18/46), chi2 = 5.638, P = 0.018]. Sputum smear conversion at the end of the 8th month was related to age, course of disease, therapeutic regimen, and the type of drug-resistance (all P < 0.05). The side-effect rate of the drug-resistant regimen group was 23.9% (17/71), higher than that of the retreatment regimen group [18.6% (8/43)], but not significantly (chi2 = 0.446, P = 0.504).The drug-resistant regimen recommended above is more effective than the retreatment regimen and should be considered in the areas where the WHO guideline fails to be followed or drug sensitivity test (DST) cannot be conducted and adjusted according to the results of DST and treatment. |
| 2008 | Bactericidal and sterilizing activities of several orally administered combined regimens against Mycobacterium ulcerans in mice. | Antimicrob Agents Chemother | Treatment with rifampin-clarithromycin or moxifloxacin-clarithromycin for 8 weeks displayed promising bactericidal activity against Mycobacterium ulcerans in mice; none of the mice treated with rifampin-clarithromycin relapsed, whereas 59% of those treated with moxifloxacin-clarithromycin relapsed after treatment was stopped. The bactericidal and sterilizing activities of the five-times-weekly (5/7) administration of 5 mg of rifapentine/kg of body weight, either alone or in combination, were virtually identical to those of the corresponding regimens with 10 mg of rifampin/kg of body weight; however, because of the long half-life of rifapentine, accumulation of the drug after 5/7 administration is a concern. The bactericidal activity of 20 mg/kg rifapentine in monotherapy or 20 mg/kg rifapentine in combination with 150 mg/kg Streptomycin or 200 mg/kg moxifloxacin administered twice weekly was as effective as the corresponding regimens containing 10 mg/kg rifampin administered 5/7, suggesting that Buruli ulcer might be treated with intermittently administered rifapentine-containing combinations. |
| 2007 | Overview of anti-tuberculosis (TB) drugs and their resistance mechanisms. | Mini Rev Med Chem | One-third of the world's population is infected with Mycobacterium (M.) tuberculosis. Tuberculosis continues to be the most common infectious cause of death and still has a serious impact, medically, socially and financially. Multidrug-resistant tuberculosis (MDR-TB), caused by tubercle bacilli that are resistant to at least isoniazid and rifampin, is among the most worrisome elements of the pandemic of antibiotic resistance because TB patients for whom treatment has failed have a high risk of death. Drugs used to treat tuberculosis are classified into first-line and second-line agents. First-line essential anti-tuberculosis agents are the most effective, and are a necessary component of any short-course therapeutic regimen. The drugs in this category are isoniazid, rifampin, ethambutol, pyrazinamide and Streptomycin. Second-line anti-tuberculosis drugs are clinically much less effective than first-line agents and elicit severe reactions much more frequently. These drugs include para-aminosalicylic acid (PAS), ethionamide, cycloserine, amikacin and capreomycin. New drugs, which are yet to be assigned to the above categories, include rifapentine, levofloxacin, gatifloxacin and moxifloxacin. Recently there has been much development in the molecular pharmacology of anti-tuberculosis drugs. This review summarizes information for isoniazid, rifampicin, ethambutol, pyrazinamide, and fluoroquinolones, and describes their resistance mechanisms. |
| 2003 | [A study on the clinical efficacy of a combination regimen with levofloxacin and capreomycin in the treatment of multi-drug resistant pulmonary tuberculosis]. | Zhonghua Jie He He Hu Xi Za Zhi | To study the clinical efficacy of a combination therapy with levofloxacin (LVFX), capreomycin (CPM) and other second-line antituberculosis drugs in the treatment of multi-drug resistant pulmonary tuberculosis (MDR-TB).177 patients with MDR-TB were assigned to a study group (88 cases), treated with LVFX, CPM, pyrazinamide (PZA), rifapentine (RFT) and pasiniazid (PSZ); or a control group, treated with Streptomycin (SM), ethambutol (EMB), PZA, RFT and PSZ. The course of treatment was 21 months.82 cases in the study group and 79 cases in the control group completed the treatment. The sputum negative conversion rate in the study group (83%) was significantly higher than that in the control group (58%) (P < 0.01). The radiographic improvement rate was 50% in the study group, significantly higher than that in the control group (28%) (P < 0.01). The closure rate of the lung cavities in the study group (63%) was higher than that in the control group (42%) (P < 0.05). No significant difference was found in side-effects between the two groups (31% in the study group, and 35% in the control group respectively) (P > 0.05).The regimen including LEVX, CPM and other second-line anti-TB drugs was effective and safe for patients with MDR-TB. |
| 2002 | Rifapentine and isoniazid in the continuation phase of a 6-month regimen. Final report at 5 years: prognostic value of various measures. | Int J Tuberc Lung Dis | Clinical trial in 672 patients with newly diagnosed pulmonary tuberculosis in Hong Kong. After an initial 2 months of a four-drug intensive phase consisting of thrice-weekly Streptomycin, isoniazid, rifampicin and pyrazinamide (SHRZ), a random allocation was made to a continuation phase of once-weekly 600 mg rifapentine + 15 mg/kg isoniazid (HRp1), HRp1 given in 2 of every 3 weeks (HRp1.2/3), or to thrice-weekly isoniazid + rifampicin (HR3), the standard treatment in Hong Kong.Final report evaluating adverse events (46 relapses and one failure) after 5 years and the prognostic influence of various factors.Kaplan-Meier analysis of adverse events and Cox proportional hazards analysis of prognostic factors.The two rifapentine regimens, HRp1 and HRp1.2/3 had similar final rates of adverse events of 10.8% and 11.7%, respectively, compared to 4.2% for the HR3 regimen (P = 0.02 and 0.009, respectively). In the initial univariate proportional hazards analysis, adverse events were significantly related to the regimen, age, sex, pretreatment radiographic extent of disease and cavitation, and also to sputum culture at 2 months. In the final multivariate analysis, after step-wise removal of non-significant factors, adverse events were related only to the regimen, patients' sex and pretreatment radiographic extent of disease. Elderly male patients were more at risk of an adverse event, as were those with more severe disease. Adverse events occurred at life table rates of 9.0% in patients with drug-sensitive strains and in 8.9% of those with initially isoniazid-resistant organisms at 5 years.The two rifapentine regimens were unsatisfactory because of their high incidence of adverse events. Isoniazid appeared not to contribute to preventing relapse. Further studies with increased rifapentine dosage are necessary. |
| 2001 | Effectiveness of once-weekly rifapentine and moxifloxacin regimens against Mycobacterium tuberculosis in mice. | Antimicrob Agents Chemother | Mice infected with 1.6 x 10(7) CFU of Mycobacterium tuberculosis were treated 14 days later for 6 months with a regimen of once-weekly 10 mg of rifapentine and 75 mg of isoniazid per kg of body weight supplemented with either 150 mg of Streptomycin per kg or 100 mg of moxifloxacin per kg during either both the 2-week daily initial and once-weekly continuation phases or only in the daily 2-week initial phase. On completion of treatment, all lung cultures were negative, except for three mice, each with a single colony: two whose rifapentine-isoniazid regimen was supplemented with Streptomycin during the whole course of therapy and one whose rifapentine-isoniazid regimen had no initial daily phase, but was supplemented with Streptomycin and moxifloxacin during the whole course of therapy. After 3 months of follow-up, positive lung cultures were obtained from 61 and 56% of mice supplemented with Streptomycin during either the full course of therapy or only the daily 2-week initial phase, respectively, and 15 and 50% of mice supplemented with moxifloxacin during either the full course of therapy or only the daily 2-week initial phase, respectively. These results suggest that moxifloxacin has sterilizing activity against M. tuberculosis. |
| 2000 | Antituberculosis activity of once-weekly rifapentine-containing regimens in mice. Long-term effectiveness with 6- and 8-month treatment regimens. | Am J Respir Crit Care Med | The effectiveness of various once-weekly 10 mg/kg rifapentine (P)- containing regimens for treatment of tuberculosis was assessed in mice infected intravenously with 4.3 x 10(6) colony-forming units (cfu) of Mycobacterium tuberculosis H37Rv, and treated 14 d later with various combinations of rifampin (R), P, isoniazid (H), pyrazinamide (Z), ethambutol (E), or Streptomycin (S). Control mice treated daily with either 2-mo HRZ + 4-mo HR or 2-mo HRZ + 6-mo HE were rendered spleen and lung culture-negative at 6 mo and 8 mo, respectively. Treatment failure with emergence of R-resistant bacilli occurred in all mice given once-weekly monotherapy with P for 6 mo. Once-weekly PH treatment was successful at 6 mo when it was preceded by a 2-mo daily phase with HRZ. When the initial daily phase was reduced to 2 wk, once-weekly PH-containing treatment was successful, at 6 mo, only if it was supplemented with S during the initial daily and the once-weekly phases, and at 8 mo if it was supplemented with daily H during the once-weekly phase. Without these supplements, once-weekly treatment failed in some mice with selection of R-resistant or H-resistant mutants. |
| 2000 | Rifapentine and isoniazid in the continuation phase of a 6-month regimen. Interim report: no activity of isoniazid in the continuation phase. | Int J Tuberc Lung Dis | Clinical trial amongst 762 patients with newly diagnosed pulmonary tuberculosis in Hong Kong. After an initial 2 months of a four-drug intensive phase consisting of Streptomycin, isoniazid, rifampicin and pyrazinamide (SHRZ), a random allocation in continuation to once-weekly rifapentine + isoniazid (HRp1), HRp1 given in 2 of every 3 weeks (HRp1.2/3), or to three times weekly isoniazid + rifampicin (HR3).Interim report evaluating progress of study and the role of isoniazid in the continuation phase.Kaplan-Meier analysis and response of patients related to susceptibility of pretreatment organisms to isoniazid and to rate of isoniazid acetylation determined by NAT2 genotyping.In the 30-month follow-up, rates for adverse treatment events (failure and relapse) were 4.2% in the HR3, 10.2% in the HRp1 and 11.2% in the HRp1.2/3 series (P = 0.02 for HR3 vs HRp1 and P = 0.01 for HR3 vs HRp1.2/3). Occurrence of adverse events was not related to initial susceptibility to isoniazid nor to the rate of acetylation of isoniazid.The two rifapentine regimens had similar final rates of adverse events which were unsatisfactory. Isoniazid had little or no activity in the continuation phase, indicating that no improvement of the continuation regimen is likely to be obtained by alteration of the isoniazid dosage. |
| 1998 | Rifapentine and isoniazid in the continuation phase of treating pulmonary tuberculosis. Initial report. | Am J Respir Crit Care Med | A randomized comparison has been made of three times weekly rifampin plus isoniazid (HR3) with rifapentine plus isoniazid given once weekly (HRp1) or on 2 of 3 wk (HRp1.2/3) in the continuation phase of 6-mo regimens (each starting with an initial 2 mo of 4-drug therapy) for the treatment of pulmonary tuberculosis in 672 Chinese patients in Hong Kong. Because of poor bioavailability of the rifapentine used (produced in China), its dose size was increased from 600 mg initially to about 750 mg in the last third of patients to obtain serum concentrations similar to those with rifapentine of Western origin; all doses were given after a meal promoting absorption. After initial exclusions, an intent to treat analysis, done on the remaining 592 patients, showed 45 adverse treatment events in 7 of 190 HR3 patients, in 17 of 199 HRp1 patients, and in 21 of 203 HRp1.2/3 patients; of these, 42 were bacteriological or radiographic relapses after the end of treatment (HR3 versus HRp1, p = 0.04; HR3 versus HRp1.2/3, p = 0.01). Patients with organisms initially sensitive or resistant to isoniazid or Streptomycin had similar relapse rates. The high relapse rate in the HRp1 regimen suggests that the rifapentine dose should be increased. Similarity of relapse rates, 8.9% and 10.4%, after the HRp1 and HRp1.2/3 regimens, respectively, indicates that irregularity in taking rifapentine/isoniazid could be tolerated. The few adverse side effects in the continuation phase in the rifapentine regimens were less frequent than in the HR3 regimen. |
| 1998 | Once-weekly rifapentine-containing regimens for treatment of tuberculosis in mice. | Am J Respir Crit Care Med | The bactericidal activities of several once-weekly rifapentine (P)-containing combination regimens against Mycobacterium tuberculosis, and their ability to prevent the selection of rifampin (R)-resistant mutants, were compared with those of the standard six-times-weekly regimen consisting of R, isoniazid (H), and pyrazinamide (Z) in a mouse experiment. Mice were infected intravenously with 1.3 x 10(7) cfu of M. tuberculosis strain H37Rv, and 8 wk of treatment began on Day 14 after infection, when mice were randomly allocated to an untreated control group and nine treatment groups of 30 mice each. At the end of 8 wk of treatment, all the tested regimens showed promising bactericidal activities. Once-weekly P alone was less bactericidal than six-times-weekly R alone; likewise, the once-weekly P-containing combined regimens were less bactericidal than the six-times-weekly standard regimen. However, the difference in killing was about 1 log10, which represented only a fraction of the overall 4 log10 to 5 log10 magnitude of killing effects. The addition of Streptomycin (S) improved the bactericidal effect of once-weekly PHZ, and the effect of once-weekly PHZS was further enhanced when it was preceded by 2 wk of daily HZS. The latter regimen achieved the same level of activity as the standard six-times-weekly regimen. All of the once-weekly P-containing combined regimens were able to prevent the selection of R-resistant mutants, whereas monotherapy with R or P selected resistant mutants in approximately 50% of animals. |
| 1995 | New drugs for tuberculosis. | Eur Respir J Suppl | Since the late 1960s, tuberculosis has been successfully cured with antibiotics. With the introduction of rifampin, "short course" regimens using isoniazid and rifampin together with either Streptomycin, ethambutol or pyrazinamide, for 6-9 months, have been successfully adopted. The spread of drug resistant M. tuberculosis strains in large urban areas has made this armamentarium of drugs insufficient, calling for the development of new drugs. Among rifamycin derivatives, rifabutin is more active than rifampin in vitro and in experimental animals, and allows sputum conversion rats of 95-100%. It is effective in treating multidrug-resistant tuberculosis. Rifapentine is more active than rifampin in vitro and has a longer half-life, but it is not active against rifampin-resistant strains. Fluoroquinolones concentrate within macrophages, are effective against M. tuberculosis and act synergistically with rifampin and isoniazid. Ofloxacin, ciprofloxacin, sparfloxacin and lomefloxacin have been evaluated as antimycobacterial agents, and no cross-resistance with major antituberculous drugs has been found. Several other drugs, including new inhibitors of beta-lactamase and new beta-lactamase-resistant antibiotics, the aminoglycoside antibiotic, paromomycin, and the new nitroimidazole, 2-ethyl-5-intro-2.3-dihydro imidazo-oxazole, have been found to be active in vitro against M. tuberculosis. |
| 1994 | Antimycobacterial drugs. | Semin Respir Infect | This review consists of the following three sections: (1) General principles in selecting antimycobacterial drugs for the treatment regimens, (2) The antimicrobial activity in vitro with an emphasis on inhibitory and bactericidal potency of various agents, and (3) Drug susceptibility testing including methodology and interpretation of the test results. Each of these sections addresses three groups of antimycobacterial agents: (1) against tuberculosis, (2) against Mycobacterium avium complex infections, and (3) against infections caused by M. fortuitum and M chelonae. The following are the drugs examined in the sections and subsections of this review: isoniazid, ethionamide, thiacetazone, rifampin, rifabutin, rifapentine, KRM-1648, pyrazinamide, Streptomycin, kanamycin, amikacin, capreomycin, gentamicin, tobramycin, ethambutol, para-aminosalicylic acid, D-cycloserine, ofloxacin, levofloxacin, ciprofloxacin, sparfloin, clofazimine, clarithromycin, azithromycin, erythromycin, cefoxitin, cefmetazole, imipenem, sulfamethoxazole, sulfisoxazole, sulfadiazine, sulfathiazole, trimethoprim, and doxycycline. |
| 1993 | In vitro activities of new macrolides and rifapentine against Brucella spp. | Antimicrob Agents Chemother | We have tested the in vitro activities of Streptomycin, rifampin, tetracyclines, trimethoprim-sulfamethoxazole, erythromycin, four new macrolides (roxithromycin, azithromycin, clarithromycin, and dirithromycin), and rifapentine against 62 strains of Brucella spp. Azithromycin and clarithromycin were, respectively, eight- and twofold more active than erythromycins (MIC for 90% of strains = 2, 8, and 16 micrograms/ml, respectively). The activity of rifapentine was similar to that of rifampin (MIC for 90% of strains = 1 microgram/ml). |