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Rifaximin, a broad-spectrum antibiotic, boasts a unique chemical composition and pharmacokinetic profile, rendering it highly effective in treating irritable bowel syndrome (IBS). Its minimal systemic absorption confines its impact to the gastrointestinal (GI) tract, where it yields significant therapeutic benefits. This review examines rifaximin's physico-chemical attributes and its role in managing IBS symptoms. Its molecular structure facilitates intestinal lumen retention postoral administration, minimizing systemic exposure and adverse effects. This targeted action is crucial in addressing the gut microbiota's role in IBS pathophysiology. By modifying microbial populations and their metabolite production, rifaximin mitigates symptoms like bloating, irregular bowel habits, and abdominal pain associated with IBS. It achieves this by reducing pathogenic bacteria and altering bacterial metabolism, enhancing mucosal and immune function. Clinical trials affirm rifaximin's superiority over placebo and conventional therapies in alleviating overall IBS symptoms and addressing small intestine bacterial overgrowth (SIBO). Despite its promising efficacy and sustained symptom relief, further research is essential to optimize long-term effectiveness and dosing regimens. Rifaximin stands as a vital treatment option for IBS due to its distinctive properties and clinical utility; yet, ongoing investigation is imperative for maximizing its therapeutic benefits., (© 2024 Deutsche Pharmazeutische Gesellschaft.)

Rifaximin, derived from rifamycin, is a broad-spectrum antibiotic by inhibiting bacterial RNA synthesis. Rifaximin has a very low intestinal absorption and exerts its antimicrobial activity primarily in the intestinal tract. It regulates the gut microbiota with limited side effects systemically. Rifaximin has been recommended for the treatment of hepatic encephalopathy but some studies shed light on its medicinal effects in many other diseases. For instance, rifaximin may suppress the progression of liver fibrosis and its related complications, and ameliorate metabolic dysfunction-associated steatotic liver disease and alcohol-associated liver disease, etc. Rifaximin can also mediate anti-inflammation, antiproliferation, and proapoptotic events by activating pregnane X receptor, which is efficious in cancers such as colon cancer. In addition, some investigations have shown rifaximin may play a therapeutic role in various autoimmune and neurological disorders. However, these findings still need more real-world practices and in-depth investigations to obtain more precise indications and fully elucidate the multifaceted potentials of rifaximin., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Competing Interests: Declaration of competing interest None declared.

The management of patients with diverticular disease remains challenging. The aim of this national survey was to assess how gastroenterologists and general practitioners use rifaximin to manage diverticulosis and diverticular disease. Members of the Italian Association of Hospital Gastroenterologists and Endoscopists (AIGO) and the Italian Federation of General Practitioners (FIMMG) were invited to complete a 39-item online survey concerning the use of rifaximin in five clinical settings: (1) diverticulosis; (2) reducing symptoms in symptomatic uncomplicated diverticular disease; (3) reducing the occurrence of diverticulitis in patients with symptomatic uncomplicated diverticular disease (primary prevention); (4) reducing the recurrence of diverticulitis in patients with previous attacks of diverticulitis (secondary prevention); (5) treatment of uncomplicated acute diverticulitis. A total of 1094 physicians completed the survey. Overall, 25.1%, 83.5%, 68%, 74.2%, and 63% of physicians prescribed rifaximin for the clinical settings 1, 2, 3, 4, and 5, respectively. In each clinical setting, the dosage of rifaximin most frequently used was 800 mg/day, the most common duration of therapy was 7 days, and the cyclic administration of treatment (expressed in months) most frequently used was > 24 months. These results highlight that a reappraisal of the use of rifaximin in patients with diverticulosis and diverticular disease is required to reduce the gap between the evidence available and the daily clinical practice, optimizing also the use of healthcare resources., (© 2024. The Author(s), under exclusive licence to Società Italiana di Medicina Interna (SIMI).)

Background: Irinotecan is a chemotherapeutic drug widely used to treat solid tumors. However, its effectiveness is limited by the severely delayed onset of diarrhea. This study aimed to confirm the protective effects of the non-systemic oral antibiotic rifaximin on irinotecan-induced mucositis in mice model., Materials and Methods: Six to eight week-old BALB/c mice were treated with saline, irinotecan (50 mg/kg, i.p. once daily), rifaximin (50 mg/kg, p.o. twice daily), or irinotecan + rifaximin for 9 consecutive days. Signs of diarrhea, bloody diarrhea, and body weight were monitored daily. Intestinal tissues were harvested for histopathological analysis and quantitative PCR. SN38 and SN38G concentration in intestine were detected using LC-MS analysis. Intestinal bacteria β-glucuronidase (BGUS) activity was detected using mouse feces. We performed 16S rRNA sequencing to investigate the gut microbiota composition. Gut permeability was tested in vivo by measuring the fluorescein isothiocyanate-dextran intensity in the serum., Results: Rifaximin reduced the frequency of delayed diarrhea and attenuated the severity of diarrhea caused by irinotecan in mice. Rifaximin significantly inhibited SN38 exposure in intestine and irinotecan-induced increase in BGUS activity. Rifaximin alleviated intestinal mucosal inflammation, prevented intestinal epithelial damage caused by irinotecan, and maintained gut barrier function. Moreover, the consecutive use of rifaximin did not cause a disorder in gut microbiota and reduced irinotecan-induced Firmicutes expansion. More importantly, rifaximin inhibited the expansion of some microbiota (such as Blautia , Eggerthella , and f_Enterobacteriaceae) and promoted an increase in beneficial microbiota (such as Lactobacillus intestinalis , Lachnospiraceae NK4A136 group , and f_Oscillospiraceae)., Conclusions: Preventive use of rifaximin is a feasible method to protect against irinotecan-induced diarrhea.

Background: Vasodilatation and bacterial dislocation are the main contributors to the catastrophic events in patients with decompensated liver cirrhosis (DLC)., Aim: The aim of this study was to evaluate the impacts of adding midodrine and rifaximin on morbidity, mortality, and quality of life in patients with DLC., Methods: This interventional clinical study included 100 consecutively enrolled DLC patients randomized 1 : 1 into two groups. Group A received oral midodrine (5 mg/8 h) and rifaximin (550 mg/12 h) with standard diuretic therapy, while group B received only standard diuretic therapy. Clinical and laboratory data, including the McGill Quality of Life Questionnaire, were evaluated over a 3-month treatment period., Results: In the study group, there was a significant reduction in Child-Pugh and Model for End-Stage Liver Disease scores, international normalized ratio, and mean arterial blood pressure at 2, 6, and 12 weeks (P < 0.05). Ascites, spontaneous bacterial peritonitis incidence, hematemesis, paracentesis need, and hepatic encephalopathy showed improvement after 12 weeks compared with the control group. McGill Quality of Life Questionnaire significantly improved after 6 and 12 weeks (P < 0.05). Survival rates demonstrated a noteworthy improvement (P = 0.014), substantiated by evidence in both univariate and multivariate regression analyses., Conclusion: Combined midodrine with rifaximin represents an endowment to patients with DLC with spectacular improvements in synthetic liver functions, along with improved quality of life, and survival., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Multi-drug or rifamycin-resistant tuberculosis (MDR/RR-TB) is an important public health concern, including in settings with high HIV prevalence. TB drug resistance can be directly transmitted or arise through resistance acquisition during first-line TB treatment. Limited evidence suggests that people living with HIV (PLHIV) might have an increased risk of acquired rifamycin-resistance (ARR)., Methods: To assess HIV as a risk factor for ARR during first-line TB treatment, a systematic review and meta-analysis was conducted. ARR was defined as rifamycin-susceptibility at treatment start with rifamycin-resistance diagnosed during or at the end of treatment, or at recurrence. PubMed/MEDLINE, CINAHL, Cochrane Library, and Google Scholar databases were searched from inception to 23 May 2024 for articles in English; conference abstracts were also searched from 2004 to 2021. The Mantel-Haenszel random-effects model was used to estimate the pooled odds ratio of any association between HIV and ARR among individuals receiving first-line TB treatment., Results: Ten studies that included data collected between 1990 and 2014 were identified: five from the United States, two from South Africa and one each from Uganda, India and Moldova. A total of 97,564 individuals were included across all studies, with 13,359 (13.7%) PLHIV. Overall, 312 (0.32%) acquired rifamycin-resistance, among whom 115 (36.9%) were PLHIV. The weighted odds of ARR were 4.57 (95% CI, 2.01-10.42) times higher among PLHIV compared to HIV-negative individuals receiving first-line TB treatment., Conclusion: The available data, suggest that PLHIV have an increased ARR risk during first-line TB treatment. Further research is needed to clarify specific risk factors, including advanced HIV disease and TB disease severity. Given the introduction of shorter, 4-month rifamycin-based regimens, there is an urgent need for additional data on ARR, particularly for PLHIV., Systematic Review Registration: PROSPERO CRD42022327337., (© 2024. The Author(s).)

Introduction: Critically ill patients with cirrhosis admitted to the intensive care unit (ICU) are usually on broad-spectrum antibiotics because of suspected infection or as a hospital protocol. It is unclear if additional rifaximin has any synergistic effect with broad-spectrum antibiotics in ICU patients with acute overt hepatic encephalopathy (HE)., Methods: In this double-blind trial, patients with overt HE admitted to ICU were randomized to receive antibiotics (ab) alone or antibiotics with rifaximin (ab + r). Resolution (or 2 grade reduction) of HE, time to resolution of HE, in-hospital mortality, nosocomial infection, and changes in endotoxin levels were compared between the 2 groups. A subgroup analysis of patients with decompensated cirrhosis and acute-on-chronic liver failure was performed., Results: Baseline characteristics and severity scores were similar among both groups (92 in each group). Carbapenems and cephalosporin with beta-lactamase inhibitors were the most commonly used ab. On Kaplan-Meier analysis, 44.6% (41/92; 95% confidence interval [CI], 32-70.5) in ab-only arm and 46.7% (43/92; 95% CI, 33.8-63) in ab + r arm achieved the primary objective ( P = 0.84).Time to achieve the primary objective (3.65 ± 1.82 days and 4.11 ± 2.01 days; P = 0.27) and in-hospital mortality were similar among both groups (62% vs 50%; P = 0.13). Seven percent and 13% in the ab and ab + r groups developed nosocomial infections ( P = 0.21). Endotoxin levels were unaffected by rifaximin. Rifaximin led to lower in-hospital mortality (hazard ratio: 0.39 [95% CI, 0.2-0.76]) in patients with decompensated cirrhosis but not in patients with acute-on-chronic liver failure (hazard ratio: 0.99 [95% CI, 0.6-1.63]) because of reduced nosocomial infections., Discussion: Reversal of overt HE in those on ab was comparable with those on ab + r., (Copyright © 2023 by The American College of Gastroenterology.)

The pathophysiology of hepatic encephalopathy (HE) is complex, with hyperammonemia playing a central role in its development. Traditional therapies for HE have targeted ammonia and include medications such as lactulose and rifaximin. Although these agents are considered standard of care, nontraditional treatments seek to affect other factors in the pathogenesis of HE. Finally, procedural therapies include albumin dialysis, shunt closure, and the ultimate cure for HE, which is liver transplant. The treatments discussed provide alternative options for patients who have failed standard of care. However, more high-quality studies are needed to routinely recommend many of these agents., Competing Interests: Disclosure Financial support: None. Conflicts of interest: None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Abdominal bloating is a common complaint in patients with functional and organic bowel disease. Rifaximin, a nonabsorbable antibiotic, has been tried for the treatment of this disease. We performed a systematic review and meta-analysis to study the efficacy of rifaximin in abdominal bloating and distension in patients with functional gastrointestinal disorders (FGID)., Methods: We accessed 4 databases (MEDLINE, Embase, SCOPUS, and Web of Science) to identify randomized placebo-controlled trials that utilized rifaximin in FGID. We excluded observational studies, those including patients with organic bowel disorders such as inflammatory bowel diseases, or those in which rifaximin was given for other indications, such as hepatic encephalopathy., Results: A total of 1426 articles were available, of which 813 articles were screened after removing duplicates and 34 articles were selected for full-text review. Finally, 10 trials (3326 patients) were included. Rifaximin was administered in doses ranging from 400 to 1650 mg per day for 1 to 2 weeks. Rifaximin therapy led to a higher likelihood of improvement in symptoms of bloating (44.6% vs. 34.6%, RR 1.22, 95% CI 1.11, 1.35; n=2401 patients) without significant heterogeneity. However, daily doses less than 1200 mg/day were similar to placebo ( P =0.09). Bloating was quantified subjectively in 7 studies, and rifaximin led to a greater reduction in bloating scores compared with placebo (standardized mean difference -0.3, 95% CI -0.51, -0.1, P =0.04) but carried significant heterogeneity ( I2 =61.6%, P =0.01)., Conclusions: Rifaximin therapy is associated with an increased likelihood of improvement in bloating and distension, as well as reduces the subjective severity of these symptoms in patients with FGID., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Hepatic encephalopathy (HE) is prevalent and is associated with increased morbidity and mortality among patients with cirrhosis. On October 1, 2022, a new, specific International Classification of Diseases-10 code for HE, K76.82, was introduced. We aimed to analyze the diagnostic accuracy of K76.82., Methods: Diagnostic performance of K76.82 for HE (sensitivity, specificity, positive predictive ratio, and negative predictive ratio) was evaluated in 2 large health systems compared with lactulose, rifaximin, and K72.90., Results: A total of 2,483 patients were analyzed. The combination term "lactulose or rifaximin" showed the highest sensitivity of >98% while K76.82 demonstrated a specificity of >87% in all cohorts., Discussion: Although K76.82 is promising, the combination term "lactulose or rifaximin" identified patients with HE more accurately., (Copyright © 2023 by The American College of Gastroenterology.)

Objective: Aim: To investigate the effectiveness of rifaximin and probiotics for the correction of intestinal permeability in patients with metabolic-associated fatty liver disease (MAFLD) in combination with type 2 diabetes mellitus., Patients and Methods: Materials and Methods: The prospective interventional randomized investigation included 68 patients with MAFLD in combination with type 2 diabetes, who were examined and divided into the 2 groups of treatment., Results: Results: The serum levels of interleukin (IL) - 6, IL-10 and zonulin, indicators of liver functional activity, liver attenuation coefficient between treatment group vs. control group after 2 weeks, 1 month, 3 and 6 months of therapy were significant differed. The serum levels of IL-6 and zonulin significantly decreasing and increasing of IL-10 in the treatment group after 2 weeks, 1, 3 and 6 months of combined therapy. When comparing of stool short-chain fatty acids concentration between treatment group vs. control group after 2 weeks, 1 month, 3 and 6 months of therapy the levels of acetic, butyric and propionic acids significantly differences and increase in their levels were established., Conclusion: Conclusions: The results of the study in dynamics during 6 months show that the additional appointment of rifaximin, multispecies probiotic and prebiotic to metformin in patients with MAFLD and type 2 diabetes led to the elimination of subclinical inflammation, modulation of the permeability of the intestinal barrier and lowering increased intestinal permeability, as well as to the lower serum activity of liver aminotransferases and decrease the stage of steatosis.

Rifaximin-α is a gut-targeted antibiotic indicated for numerous gastrointestinal and liver diseases. Its multifaceted mechanism of action goes beyond direct antimicrobial effects, including alterations in bacterial virulence, cytoprotective effects on host epithelial cells, improvement of impaired intestinal permeability, and reduction of proinflammatory cytokine expression via activation of the pregnane X receptor. Rifaximin-α is virtually non-absorbed, with low systemic drug levels contributing to its excellent safety profile. While there are high concentrations of drug in the colon, low water solubility leads to low colonic drug bioavailability, protecting the gut microbiome. Rifaximin-α appears to be more active in the bile-rich small bowel. Its important biologic effects are largely at sub-inhibitory concentration. Although in vitro testing of clinical isolates from rifaximin recipients has revealed rifaximin-resistant strains in some studies, the risk of emergent rifaximin-α resistance appears to be lower than for many other antibiotics. Rifaximin-α has been used for many years for traveler's diarrhea with no apparent increase in resistance levels in causative pathogens. Further, rifaximin-α retains its efficacy after long-term and recurrent usage in chronic gastrointestinal disorders. There are numerous reasons why the risk of microbial resistance to rifaximin-α may be lower than that for other agents, including low intestinal bioavailability in the aqueous colon, the mechanisms of action of rifaximin-α not requiring inhibitory concentrations of drug, and the low risk of cross transmission of rifaximin-α resistance between bacterial species. Reported emergence of vancomycin-resistant Enterococcus in liver-disease patients maintained on rifaximin needs to be actively studied. Further studies are required to assess the possible correlation between in vitro resistance and rifaximin-α efficacy., Competing Interests: Between 1992 and 2003, H.L.D. worked with Salix, who owned rifaximin and sponsored H.L.D.’s studies that led to licensure of rifaximin for travelers' diarrhea. When the patent of rifaximin came into question and became a federal lawsuit in 2022, H.L.D. received payment for appearing in federal court to discuss the history of rifaximin and timetable for use.

Tuberculosis (TB) preventive therapy (TPT) is an effective strategy to eliminate TB in low-incidence settings. Shorter TPT regimens incorporating the antimicrobial class of rifamycins are designed to improve adherence and completion rates but carry the risk of modifications to the gut microbiota. We enrolled six subjects diagnosed with latent TB infection (LTBI) who accepted to initiate TPT. We also enrolled six healthy volunteers unexposed to the rifamycins. We profiled the gut microbiota using 16S rRNA amplicon sequencing (V1-V2 region) to document the immediate effect of rifamycin-based TPT on the gut microbiota composition and tracked recovery to baseline two months after TPT. Overall, TPT accounted for 17% of the variance in gut microbial community dissimilarity. This rifamycin-based TPT induced dysbiosis was characterized by a depletion of butyrate-producing taxa (Clostridium-XIVa and Roseburia) and expansion of potentially pathogenic taxa within the Firmicutes and Proteobacteria phyla. Recovery of the gut microbial composition was incomplete two months after TPT. Robust clinical studies are necessary to comprehensively catalogue TPT-induced gut microbiota dysbiosis to inform strategies to mitigate potential long-term sequelae of this important TB control intervention., (© 2023. The Author(s).)

Antimicrobial resistance has emerged as a global public health threat, and development of novel therapeutics for treating infections caused by multi-drug resistant bacteria is urgent. Staphylococcus aureus is a major human and animal pathogen, responsible for high levels of morbidity and mortality worldwide. The intracellular survival of S. aureus in macrophages contributes to immune evasion, dissemination, and resilience to antibiotic treatment. Here, we present a confocal fluorescence imaging assay for monitoring macrophage infection by green fluorescent protein (GFP)-tagged S. aureus as a front-line tool to identify antibiotic leads. The assay was employed in combination with nanoscaled chemical analyses to facilitate the discovery of a new, active rifamycin analogue. Our findings indicate a promising new approach for the identification of antimicrobial compounds with macrophage intracellular activity. The antibiotic identified here may represent a useful addition to our armory in tackling the silent pandemic of antimicrobial resistance.

Background: Additional therapies for hepatic encephalopathy (HE) treatment are warranted. There are data evaluating the use of zinc for HE; however, clinical outcomes, specifically in the United States, are unknown., Objective: To compare 30-day and 1-year all-cause readmission rates in patients with cirrhosis complicated by HE on lactulose and rifaximin to those on lactulose, rifaximin, and zinc., Methods: This retrospective study included patients admitted with documented cirrhosis and home medications of lactulose and rifaximin, with or without zinc. Patients were stratified into 2 groups: those receiving lactulose and rifaximin for HE (control) and those receiving lactulose, rifaximin, and zinc for HE (treatment). The primary outcomes were 30-day and 1-year all-cause readmission rates., Results: One-hundred fifty-seven patients were included (102 in control group, 55 in treatment group). Regarding 30-day and 1-year all-cause readmission rates, there was no difference between the control and treatment groups., Conclusion and Relevance: This is the first study conducted in the United States evaluating zinc for HE treatment. Zinc did not impact 30-day or 1-year all-cause readmission rates. Further studies are warranted to evaluate the potential benefit of zinc for HE, possibly in correlation with Model for End-stage Liver Disease-Sodium (MELD-Na) scores.

Background: Rifaximin is an oral antimicrobial drug with a broad-spectrum effect. It locally regulates the function and structure of intestinal bacteria and decreases intestinal endotoxemia. We aimed to investigate the preventive role of rifaximin in recurrent episodes of hepatic encephalopathy in cases with a history of hepatic diseases., Methods: We searched PubMed, Scopus, and Web of Science for the relevant studies using the following search strategy: "(Rifaximin) OR (Xifaxan) AND (cirrhosis) OR (encephalopathy)." We assessed the risk of bias using Cochrane's risk of bias tool. We included the following outcomes: recurrence of hepatic encephalopathy, adverse events, mortality rate, and time to the first episode of hepatic encephalopathy from the time of randomization (days). We performed the analysis of homogeneous data under the fixed-effects model, while analysis of heterogeneous data was performed under the random-effects model., Results: We analyzed data obtained from 999 patients from 7 included trials. The overall risk ratio proved that the rifaximin group was associated with a lower recurrence rate than the control group (risk ratio [RR] = 0.61[0.50, 0.73], P = .001). We found no significant variation in both groups regarding adverse events (RR = 1.08 [0.89, 1.32], P = .41), and mortality rates (RR = 0.98 [0.61, 1.57], P = .93). The overall risk of bias results was low., Conclusion: The meta-analysis showed that in patients allocated to the rifaximin group, the incidence rate of hepatic encephalopathy was significantly lower when compared with those in the control group with no difference in both groups regarding adverse events and mortality rates.

Introduction: Since its approval in Italy in 1987, rifaximin has been licensed in over 30 countries for the treatment of a wide range gastrointestinal diseases. The aim of the study was to analyze the real world use of rifaximin 200 mg in the Campania region., Methods: An observation retrospective study was conducted analysing the prescriptions of rifaximin received by the subjects ≥18 years old resident in the Campania Region. For each user the first rifaximin prescription in 2019 was defined as index date. All the prescriptions during the 12 months following the index date were analyzed. The subjects were categorized according to the number of packages/year received (1-4, 5-12, 13-24, >24)., Results: 231,207 subjects received at least one package/year of rifaximin 200 mg with a prevalence of use of 4.9% and a total annual expenditure of 9.2 million euros. The 73.9% of users received 1-4 packages/year, 16.4% between 5-12 packages/year and 7.7% between 13-24 packages/year. The 2.0% of the users received more than 24 packages/year with an incidence on total expenditure equal to 14.8% (5% is due to those who received more than 40 packages/year)., Discussion: About two thirds of rifaximin users received no more than three packages, presumably for the treatment of the infectious gastroenteritis or diarrheal syndromes, while 24% received 5-24 packages/year probably for the relapsing chronic intestinal pathologies. The 15% of the expenditure and consumption is related to subjects receiving more than 24 packages/year, probably due to the treatment of chronic liver diseases., Conclusions: The use of rifaximin 200 mg should be further investigated in different recurrent chronic diseases, especially to verify which schemes and dosages are used in real life compared to those tested in clinical trials.

Objective Rifaximin is used to treat hepatic encephalopathy. However, whether or not rifaximin and lactulose combination therapy can enhance the treatment outcomes and reduce the hospitalization rate of patients with hepatic encephalopathy that are resistant to lactulose has yet to be determined. The present study investigated the hospitalization rate before and after rifaximin add-on therapy in patients resistant to lactulose. Methods A total of 36 patients who were resistant to lactulose with add-on rifaximin therapy were enrolled. Patients who were hospitalized and/or did not achieve normalization of ammonia levels under lactulose administration were defined as treatment-resistant. The primary outcome was the change in hospitalization rate due to hepatic encephalopathy at 24 weeks before and after rifaximin administration. Results Before rifaximin administration, 15 (41.6%) patients were hospitalized due to hepatic encephalopathy. After rifaximin administration, 8 (22.2%) patients were hospitalized due to hepatic encephalopathy. The hospitalization rates were significantly reduced after rifaximin administration (p=0.02). The median (interquartile range) ammonia levels upon rifaximin administration (baseline) and 8, 12, and 24 weeks after rifaximin administration were 124 (24-310) μg/dL, 78 (15-192) μg/dL, 67 (21-233) μg/dL, and 77 (28-200) μg/dL, respectively. Furthermore, the ammonia levels were significantly reduced by rifaximin add-on therapy (p=0.005, p=0.01, and p=0.01). Conclusion The addition of rifaximin to lactulose treatment in treatment-resistant patients decreases the hospitalization rate among patients with hepatic encephalopathy and may be used as an add-on treatment.

Background & Aims: Cirrhosis-related complications are a major burden. Rifaximin soluble solid dispersion (SSD) tablets (immediate-release [IR]; sustained extended-release [SER]) were designed to increase rifaximin water solubility. These analyses evaluate dosing for prevention of cirrhosis complication-related hospitalizations/mortality and overt hepatic encephalopathy (OHE) treatment., Methods: Two phase II, randomized, double-blind, placebo-controlled trials were conducted. Trial 1: outpatients with early decompensated cirrhosis randomized to placebo or rifaximin SSD once-nightly: IR 40 or 80 mg, SER 40 or 80 mg, or IR 80 mg plus SER 80 mg, for 24 weeks. Trial 2: inpatients with OHE randomized to lactulose plus placebo or rifaximin SSD: IR 40 mg once or twice daily or SER 80 mg once or twice daily for ≤14 days. Primary efficacy endpoint: time to cirrhosis complication-related hospitalization/all-cause mortality (Trial 1) or time to OHE resolution (Trial 2)., Results: In Trial 1 (n = 516), no significant difference in time to cirrhosis complication-related hospitalization/all-cause mortality vs placebo. In a post hoc analysis, time to all-cause hospitalization/all-cause mortality was improved with IR 40 mg vs placebo (15.4% [12/78] vs 27.7% [26/94]; P = .03). A Trial 2 prespecified interim analysis (n = 71) showed lactulose plus rifaximin SSD IR 40 mg bid significantly reduced median time to OHE resolution (21.1 hours) vs lactulose plus placebo (62.7 hours; P = .02). Trial 2 was subsequently terminated., Conclusion: Rifaximin SSD IR 40 mg may reduce hospitalizations in patients with cirrhosis and shorten duration of OHE during hospitalization-considered a negative finding, yet also hypothesis-generating. (ClinicalTrials.govNCT01904409; NCT03515044)., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Nontuberculous mycobacteria are environmental organisms that cause infections leading to chronic, debilitating pulmonary disease, among which Mycobacterium avium complex (MAC) is the most common species., Methods: We described patterns of macrolide-based multidrug antibiotic therapies for MAC pulmonary disease (MAC-PD) in US Medicare beneficiaries with bronchiectasis between January 2006 and December 2014. MAC therapy was defined as a multidrug regimen containing a macrolide plus ≥1 other drug targeting MAC-PD (rifamycin, ethambutol, fluoroquinolone, or amikacin) prescribed concomitantly for >28 days., Results: We identified 9189 new MAC therapy users, with a mean age (standard deviation) of 74 (6 years) at the start of therapy; 75% female and 87% non-Hispanic white. A guideline-based regimen (a macrolide, ethambutol, and rifamycin, with or without amikacin) was prescribed for 51% of new MAC therapy users at treatment start, of whom 41% were continuing guideline-based therapy at 6 months, and only 18% at 12 months. Of all new MAC therapy users, by 18 months only 11% were still receiving MAC treatment, 55% had discontinued therapy, and 34% were censored owing to death or the end of the study period., Conclusions: Overall, nearly half of new MAC therapy users were prescribed a non-guideline-recommended macrolide-based therapy, including regimens commonly associated with promoting macrolide resistance. Treatment discontinuation was common, and once discontinued, only a few beneficiaries resumed therapy at a later time. Our study adds important data to the current literature on treatment patterns for MAC-PD among older US populations. Future research should examine treatment patterns using more contemporary data sources., Competing Interests: Potential conflicts of interest. J. H. K. has received research grants from Moderna and GlaxoSmithKline, paid to the institution. E. H. has served on advisory board for AN2 Pharmaceuticals and received consulting fees. S. K. B. reports grants or contracts from Insmed, outside the submitted work and paid to the institution, as site subinvestigator for a clinical trial in nontuberculous mycobacteria (NTM) lung disease; payment or honoraria paid to institution from Boehringer Ingelheim; and membership on the executive committee for The Union–North American Region. T. K. M. has received grants or contracts from the Ontario Thoracic Society/Lung Foundation for a study on preventing the recurrence of Mycobacterium avium (MAC) lung disease, from Insmed as site investigator for a clinical trial on MAC lung disease, and from the Oregon Health & Science University/Patient Centered Outcomes Research Institute as site investigator for clinical trial of MAC lung disease, all paid to the institution, and from the Lung Health Foundation. T. K. M. has received consulting fees from Insmed, RedHill Biopharma, and Spero, including for MAC lung disease study design, paid to the institution; payment or honoraria from Astra Zeneca and Novartis for CME in NTM lung disease, paid to the institution; and support for attending meetings and/or travel from NTM Info & Research (NTMir) and hotel accommodation for presentation at the NTMir annual meeting for patients and providers associated with the American Thoracic Society Annual Conference in May 2019. T. K. M. has also served as chair of the data safety monitoring board for clofazimine monotherapy in MAC lung disease and has a leadership/fiduciary role as an advisor to the Toronto NTM lung disease patient support group. K. L. W. has grants or contracts and consulting fees from Paratek, AN2 Pharmaceuticals, Insmed, and Red Hill Biopharma and consulting fees from Spero Therapeutics. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Hepatic encephalopathy (HE) is a complication of cirrhosis. Rifaximin, added to lactulose, effectively maintains remission and reduces hospitalizations from HE compared with lactulose alone. Although the clinical evidence supports the use of rifaximin, concerns remain regarding the financial implications and subsequent impact on medication access and outcomes., Objective: The goal of this study was to determine whether medication access to rifaximin at hospital discharge reduces readmission and office visits related to HE., Methods: A retrospective study was conducted in compliance with local institutional review board including cirrhotic patients discharged with a rifaximin prescription for HE. Patients were stratified into 2 groups: those able to obtain rifaximin and those unable to obtain rifaximin upon discharge. The primary outcome was to evaluate the rate of HE recurrence in each group as defined as a composite of readmission or office visit for acute HE within 12 months of discharge., Results: Access to rifaximin significantly reduced the risk of hospital admission and office visit for acute HE over 12 months. A hospitalization or office visit occurred in 24.5% of patients in the medication access group compared with 50% in the group without medication access. Only 58% of patients had access to rifaximin at discharge., Conclusion and Relevance: Rifaximin use was associated with significantly reduced risk of hospitalization and office visits for HE. At discharge, 42% of patients did not have access to rifaximin regardless of being prescribed the medication, identifying that copay is a significant barrier in allowing patients to have access to rifaximin.

Introduction: Patients with hepatic encephalopathy (HE) suffer from significant symptoms and impaired quality of life. Improved understanding on the potential benefits of first-line HE therapies may aid patient-provider discussions regarding expected benefits of HE treatments. We aimed to perform a systematic review to assess the effects of lactulose and rifaximin on patient-reported outcomes (PROs)., Methods: We searched MEDLINE, EMBASE, and Cochrane Library databases for randomized trials or prospective cohort studies using lactulose and/or rifaximin for the management of HE and assessing changes in PRO using PRO instruments. Physician reviewers independently reviewed titles, abstracts, and full texts and extracted data independently. We performed random-effects meta-analyses to examine the effects of lactulose and rifaximin on PROs., Results: We identified 16 studies representing 1,376 patients that met inclusion criteria. Most studies assessed treatment of covert HE. In patients with covert HE, lactulose significantly improved overall patient-reported health-related quality of life measured by the Sickness Impact Profile with an estimated pooled mean difference of 6.92 (95% confidence interval: 6.66-7.18) and showed improvements in several subscales. Conversely, rifaximin demonstrated a nonstatistically significant mean difference in the total Sickness Impact Profile of 4.76 (95% confidence interval: -4.23 to 13.76), with strong evidence of heterogeneity between these studies. Studies examining other PRO instruments showed improvements in overall health-related quality of life, social functioning, and sleep from both lactulose and rifaximin., Discussion: Patients with HE treated with lactulose or rifaximin reported improvements in important PROs. These results may inform provider-patient communication and help manage patient expectations regarding the potential benefits of HE therapies., (Copyright © 2022 by The American College of Gastroenterology.)

Background: Tuberculosis preventive therapy (TPT) is recommended for people with HIV infection, including during pregnancy. The effect of TPT exposure at conception and during pregnancy is poorly documented., Methods: We report pregnancy outcomes among South African women with HIV enrolled in a randomized trial of 4 TPT regimens (two 3-month regimens, rifapentine/isoniazid [3HP] or rifampin/isoniazid [3HR], isoniazid for 6 months, or isoniazid continuously). Descriptive statistics and risk ratios were assessed to examine relationships between study regimens and outcomes., Results: 216/896 women (24%) conceived during the study. Women who conceived were younger (27.9 vs 31.3 years) and had higher mean CD4 counts (589.1 vs 536.7). The odds of pregnancy were higher in women in the rifamycin-isoniazid arms than those in the isoniazid arms (3HP: relative risk [RR] 1.73, P = 0.001; 3HR:RR 1.55, P = 0.017) despite increased contraceptive use compared with the standard 6H therapy. Thirty-four women became pregnant while taking preventive treatment (8 rifamycin and 26 isoniazid monotherapy). Pregnancy outcomes in these women were as follows: 17 (50%) mother/baby healthy, 3 (9%) spontaneous abortions, 6 (18%) elective abortions, 1 (3%) premature delivery, 2 (6%) neonatal deaths [1 rifamycin-isoniazid and 1 isoniazid], and 5 (15%) unknown., Conclusions: Pregnancy was common in women who had received TPT and more frequent in women who had received rifamycin-isoniazid-based regimens., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To investigate the effects of rifaximin treatment outcomes on complications and 24-week survival rate in cirrhotic patients with refractory type ascites. Methods: A retrospective cohort study was conducted on 62 cases with refractory ascites, and were divided into rifaximin treatment group (42 cases) and control group (20 cases) according to the actual treatment conditions. Rifaximin treatment group patients were administered oral rifaximin-α 200 mg four times daily for 24 consecutive weeks, and the other treatments were basically the same in both groups. Fasting body weight, ascites, complications and survival rate between the two groups were observed. Measurement data of the two groups using t-test, Mann-Whitney U test, and repeated measures analysis of variance were compared. χ 2 test or Fisher's exact test were used to compare the enumeration data between the two groups. Kaplan-meier survival analysis was used to compare the survival rates. Results: At 24-week of rifaximin treatment, patients average body weight was reduced by 3.2 kg and the average ascites depth was reduced by 4.5 cm with B-ultrasound measurement, while in the control group at 24-week, the average body weight was reduced by 1.1 kg and the average ascites depth was reduced by 2.1 cm with B-ultrasound measurement, and the differences between the two groups were statistically significant ( F =4.972, P =0.035; F =5.288, P =0.027). Hepatic encephalopathy incidence of grade II or above, hospitalization rates due to exacerbation of ascites, and spontaneous bacterial peritonitis were significantly lower in the rifaximin treatment group than those in the control group (2.4% vs . 20.0%, χ 2 =5.295, P =0.021; 11.9% vs . 50.0%, χ 2 =10.221, P =0.001; 7.1% vs . 25.0%, χ 2 =3.844, P =0.050). The 24-week survival rate was 83.3% in the rifaximin treatment group and 60.0% in the control group, P =0.039. Conclusion: Rifaximin treatment can significantly improve ascites symptoms, reduce the incidence of cirrhosis complications and improve the 24-week survival rate in cirrhotic patients with refractory type ascites.

After infection with Mycobacterium tuberculosis, a minority of individuals will progress to tuberculosis disease (TB). The risk is higher among persons with well-established risk factors and within the first year after infection. Testing and treating individuals at high risk of progression maximizes the benefits of TB preventive therapy; avoiding testing of low-risk persons will limit potential harms. Several treatment options are available; rifamycin-based regimens offer the best efficacy-safety balance. In this review, we present an overview of the diagnosis and treatment of TB infection, and summarize common clinical scenarios., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans infection that requires long-term antibiotic treatment and/or surgical excision. In this study, we investigated the therapeutic efficacy of the rifamycin derivative, rifalazil (RLZ) (also known as KRM-1648), in an advanced M. ulcerans infection model. Six-week-old female BALB/c mice were infected with 3.25 x 104 colony-forming units (CFU) of M. ulcerans subcutaneously into the bilateral hind footpads. At 33 days post-infection, when the footpads exhibited significant redness and swelling, mice were treated orally with 5 or 10 mg/kg of RLZ for up to 15 weeks. Mice were followed for an additional 15 weeks following treatment cessation. Untreated mice exhibited a progressive increase in footpad redness, swelling, and erosion over time, and all untreated mice reached to endpoint within 5-8 weeks post-bacterial injection. In the RLZ-treated mice, footpad redness and swelling and general condition improved or completely healed, and no recurrence occurred following treatment cessation. After 3 weeks of treatment, the CFU counts from the footpads of recovered RLZ-treated mice showed a 104 decrease compared with those of untreated mice. We observed a further reduction in CFU counts to the detection limit following 6 to 15 weeks of treatment, which did not increase 15 weeks after discontinuing the treatment. Histopathologically, bacteria in the treated mice became fragmented one week after RLZ-treatment. At the final point of the experiment, all the treated mice (5mg/kg/day; n = 6, 10mg/kg/day; n = 7) survived and had no signs of M. ulcerans infection. These results indicate that the rifamycin analogue, RLZ, is efficacious in the treatment of an advanced M. ulcerans infection mouse model., Competing Interests: No

Tuberculosis continues to be a major public health problem. A priority objective is the implementation of early diagnosis, contact investigation and latent tuberculosis infection (LTBI) testing. World Health Organization (WHO) concludes that there is no gold standard for the diagnosis of LTBI; both the tuberculin test and IGRA (interferon gamma release assays) indirectly identify tuberculosis infection; both tests are considered acceptable but imperfect. WHO recommends that regimens that include rifamycins are equally effective but less toxic and more adherent than long regimens with isoniazid., (©The Author 2022. Published by Sociedad Española de Quimioterapia. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)(https://creativecommons.org/licenses/by-nc/4.0/).)

Purpose of Review: We discuss the most recent literature to support the identification of children at risk for tuberculosis and optimal testing and treatment strategies., Recent Findings: The identification and management of children with tuberculosis has increased in complexity due to the recent severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) pandemic, greater use of immunosuppressive agents, and the administration of shorter, rifamycin-containing treatment regimens. Advancements in the diagnosis and treatment of tuberculosis in children include: use of interferon gamma release assays (IGRAs); molecular-based tests; and shorter courses of treatment. While the essential steps to identify and treat children at risk for tuberculosis remain unchanged, providers must be aware of impact of these challenges., Summary: The SARS-CoV-2 pandemic will likely have a negative impact on global tuberculosis control. It is important that countries maintain a comprehensive approach to the identification and management of children at risk for tuberculosis. Increasing evidence supports enhanced utilization of IGRAs and molecular-based testing to improve the diagnosis of tuberculosis in children. Shorter course, rifamycin-based treatment regimens are available to treat children with tuberculosis infection; however, their use is limited in some immunosuppressed children due to drug-drug interactions., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Tuberculosis (TB) is one of the most significant world health problems, responsible for 1.5 M deaths in 2020, and yet, current treatments rely largely on 40 year old paradigms. Although the rifamycins (RIFs), best exemplified by the drug rifampin (RMP), represent a well-studied and therapeutically effective chemotype that targets the bacterial RNA polymerase (RNAP), these agents still suffer from serious drawbacks including the following: 3-9 month treatment times; cytochrome P450 (Cyp450) induction [particularly problematic for human immunodeficiency virus- Mycobacterium tuberculosis (MTB) co-infection]; and the existence of RIF-resistant (RIF R ) MTB strains. We have utilized a structure-based drug design approach to synthesize and test 15 benzoxazinorifamycins (bxRIFs), congeners of the clinical candidate rifalazil, to minimize human pregnane X receptor (hPXR) activation while improving potency against MTB. We have determined the compounds' activation of the hPXR [responsible for inducing Cyp450 3A4 (CYP3A4)]. Compound IC 50 s have been determined against the wild-type and the most prevalent RIF R (β-S450L) mutant MTB RNAPs. We have also determined their bactericidal activity against "normal" replicating MTB and a model for non-replicating, persister MTB. We have identified a minimal substitution and have probed larger substitutions that exhibit negligible hPXR activation (1.2-fold over the dimethyl sulfoxide control), many of which are 5- to 10-fold more potent against RNAPs and MTB than RMP. Importantly, we have analogues that are essentially equipotent against replicating MTB and non-replicating persister MTB, a property that is correlated with faster kill rates and may lead to shorter treatment durations. This work provides a proof of principle that the ansamycin core remains an attractive and effective scaffold for novel and dramatically improved RIFs.

Clinical progress in the development of new diagnostic modalities and therapeutic strategies for the management of patients with hepatic encephalopathy has lagged behind the vast knowledge that has been generated from basic studies. In this article, we critically assess matters that should be revisited, such as definition, classification, diagnosis and grading of hepatic encephalopathy, which are difficult to apply reproducibly using the current criteria. Many lines of investigation have confirmed that hepatic encephalopathy is irreversible in many patients and suggest the need for further studies focussing on mechanisms of neuronal injury and death, to guide future drug development for these patients. The clinical evidence behind using lactulose for all severities of hepatic encephalopathy, which is currently considered the standard of care, is poor and placebo-controlled trials for hepatic encephalopathy should be considered ethically sound. This expert opinion identifies current challenges in hepatic encephalopathy and highlights areas which require further debate and investigation in order to help advance the field both scientifically and clinically., Competing Interests: Conflict of interest Rajiv Jalan is the inventor of OPA, which has been patented by UCL and licensed to Mallinckrodt Pharma. He is also the founder of Yaqrit Discovery, a spin out company from University College London, Hepyx Limited and Cyberliver. He has research collaborations with Takeda and Yaqrit Discovery. Christopher Rose has research collaborations with, and is an advisor for Aza Technologies, Axcella, Horizon Therapeutics, Lupin Pharma, Mallinckrodt, Morphocell Technologies and Neuractas. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2022 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background and Study Aims: Advanced liver disease frequently culminates in hepatic encephalopathy (HE), which can be classified as covert or overt HE, with subtle or clinically obvious changes respectively. 30-40% of patients with cirrhosis develop overt HE, which negatively affects the patients' quality of life. Next to lactulose, rifaximin-α has been prescribed as a second line therapy to treat and reduce the risk of recurrence of overt HE. In this study, we aimed to evaluate the effect of rifaximin-α therapy, both on the number of occurring infections and on the evolution in hospital admissions of patients with overt HE., Patients and Methods: A total of 66 cirrhotic patients, treated for at least 6 months with rifaximin-α at AZ Maria Middelares, between October 1st 2014 and January 1st 2020, were included in the study analysis. Medical records of all patients were evaluated over a period of 6 months prior and after initiation of rifaximin-α therapy., Results: Data analysis revealed that the included cirrhotic patients were severely ill, with a mean model for end-stage liver disease (MELD) score of 21, and a median Child Pugh score of 11. Among these patients, rifaximin-α treatment significantly downgraded the total number of infections, with a main effect on respiratory infections. Furthermore, rifaximin-α therapy led to a significant decrease in HE-related, as well as in other liver-related hospital admissions., Conclusions: This study confirms the potential value of rifaximin-aα in reducing the number of developing infections and hospital admissions in a severely ill cirrhotic patient population., (© Acta Gastro-Enterologica Belgica.)

Rifamycins are considered a milestone for tuberculosis (TB) treatment because of their proficient sterilizing ability. Currently, available TB treatments are complicated and need a long duration, which ultimately leads to failure of patient compliance. Some new rifamycin derivatives, i.e., rifametane, TNP-2092 (rifamycin-quinolizinonehybrid), and TNP-2198 (rifamycin-nitromidazole hybrid) are under clinical trials, which are attempting to overcome the problems associated with TB treatment. The undertaken review is intended to compare the pharmacokinetics, pharmacodynamics and safety profiles of these rifamycins, including rifalazil, another derivative terminated in phase II trials, and already approved rifamycins. The emerging resistance of microbes is an imperative consideration associated with antibiotics. Resistance development potential of microbial strains against rifamycins and an overview of chemistry, as well as structure-activity relationship (SAR) of rifamycins, are briefly described. Moreover, issues associated with rifamycins are discussed as well. We expect that newly emerging rifamycins shall appear as potential tools for TB treatment in the near future., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Data regarding the additional effect on the recurrence of hepatic encephalopathy (HE) after oral L-carnitine administration are scarce., Objective: This study aimed to assess the additional effects of L-carnitine in patients who were receiving rifaximin for HE., Methods: This randomized study comprised a screening visit and a 12-week treatment period. Patients who fulfilled the eligibility criteria were randomized to either group A (additional rifaximin) or group B (additional L-carnitine and rifaximin). Group A received 1,200 mg/day of rifaximin. Group B received 1,500 mg/day of L-carnitine and rifaximin at 1,200 mg/day. The endpoints were the changes in the portal systemic encephalopathy (PSE) index and the admission rate from the baseline for the duration of the study in both groups., Results: Eighty-three patients were randomized to either group A (n = 42) or group B (n = 41). In group A, the PSE index decreased from 0.35 ± 0.09 at baseline to 0.27 ± 0.11 on the final evaluation day (p = 0.001). In group B, the PSE index decreased from 0.37 ± 0.09 at baseline to 0.24 ± 0.11 on the final evaluation day (p = 0.001). Although there was not a significant reduction in the PSE index in group A compared to that in group B (p = 0.202), the admission rates were 30.9% and 9.8% in groups A and B, respectively. Additional L-carnitine significantly reduced the admission rate (p = 0.028)., Conclusion: L-Carnitine addition reduced the risk of hospitalization for patients who received rifaximin for HE., (© 2021 The Author(s) Published by S. Karger AG, Basel.)

Background: The purpose of the present meta-analysis was to compare the efficacy of rifaximin and nonabsorbable disaccharides (NADs) in hepatic encephalopathy (HE)., Methods: After the registration of the present meta-analysis on INPLASY, all procedures were performed according to PRISMA 2020. Relevant literature was retrieved on PubMed, Embase, and the Cochrane Library up to September 5, 2021. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the enrolled studies, and Review Manager software (version 5.3) was used to analyze the clinical efficacy, blood ammonia and adverse effects., Results: Six studies with 559 patients were included in the present meta-analysis. There were no significant differences in the basic characteristics of the included studies. Analysis of the complete resolution of HE showed that rifaximin was better than NADs (risk ratio [RR] = 1.87, 95% confidence interval [CI] = 1.03-3.39, P = .04). However, there were no significant differences in mental status (RR = 1.04, 95% CI = 0.92-1.18, P = .53), blood ammonia level (standard mean difference = -0.02, 95% CI = -0.40-0.02, P = .08), or drug adverse drug effects (OR = 0.43, 95% CI = 0.10-1.77, I2 = 56%, P = .24) between the rifaximin and NADs treatment groups., Conclusion: Rifaximin is not superior to NADs in the treatment of HE., Competing Interests: The authors have no conflicts of interests to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: Quality of life (QoL) is impaired in patients with hepatic encephalopathy and rifaximin-α can improve QoL within 6 months. This study assessed the importance of QoL as a therapeutic objective in hepatic encephalopathy management; whether QoL is routinely assessed in hepatic encephalopathy patients in clinical practice and the role of rifaximin-α in this context., Methods: A survey was conducted of healthcare professionals (HCPs) from Europe and Australia involved in hepatic encephalopathy management. HCPs rated the importance of a range of therapeutic objectives on a 1-7 Likert scale (1 = not at all important; 7 = extremely important). HCPs were also required to provide three patient record forms (PRFs) based on their last three hepatic encephalopathy patients., Results: There were 218 HCP respondents, who provided 654 PRFs (patients treated with rifaximin-α, n = 347; patients not treated with rifaximin-α, n = 307). The mean Likert score was highest for the therapeutic objective 'improving a patient's QoL' (6.4), which was rated significantly more highly than all other therapeutic objectives, including 'reducing the patient's likelihood of hospital readmission' (6.1; P < 0.001) and 'preventing death of the patient' (6.1; P < 0.001). Despite this, only 28.3% of PRFs documented specific QoL data assessment. Patients receiving rifaximin-α were treated later in their disease course than those not receiving rifaximin-α., Conclusions: HCPs consider QoL improvement the main therapeutic objective in hepatic encephalopathy management, but most do not explicitly assess QoL. Earlier introduction of rifaximin-α may safeguard QoL improvement even when QoL monitoring is not possible., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Rifamycins are a class of antibiotics that were first discovered in 1957 and are known for their use in treating tuberculosis (TB). Rifamycins exhibit bactericidal activity against many Gram-positive and Gram-negative bacteria by inhibiting RNA polymerase (RNAP); however, resistance is prevalent and the mechanisms range from primary target modification and antibiotic inactivation to cytoplasmic exclusion. Further, phenotypic resistance, in which only a subpopulation of bacteria grow in concentrations exceeding their minimum inhibitory concentration, and tolerance, which is characterized by reduced rates of bacterial cell death, have been identified as additional causes of rifamycin failure. Here we summarize current understanding and recent developments regarding this critical antibiotic class., (© 2021. The Author(s), under exclusive licence to the Japan Antibiotics Research Association.)

Background: Tuberculosis (TB) preventive therapy (TPT) is an essential component of care for people living with HIV (PLHIV). We compared efficacy, safety, completion, and drug-resistant TB risk for currently recommended TPT regimens through a systematic review and network meta-analysis (NMA) of randomized trials., Methods and Findings: We searched MEDLINE, Embase, and the Cochrane Library from inception through June 9, 2020 for randomized controlled trials (RCTs) comparing 2 or more TPT regimens (or placebo/no treatment) in PLHIV. Two independent reviewers evaluated eligibility, extracted data, and assessed the risk of bias. We grouped TPT strategies as follows: placebo/no treatment, 6 to 12 months of isoniazid, 24 to 72 months of isoniazid, and rifamycin-containing regimens. A frequentist NMA (using graph theory) was carried out for the outcomes of development of TB disease, all-cause mortality, and grade 3 or worse hepatotoxicity. For other outcomes, graphical descriptions or traditional pairwise meta-analyses were carried out as appropriate. The potential role of confounding variables for TB disease and all-cause mortality was assessed through stratified analyses. A total of 6,466 unique studies were screened, and 157 full texts were assessed for eligibility. Of these, 20 studies (reporting 16 randomized trials) were included. The median sample size was 616 (interquartile range [IQR], 317 to 1,892). Eight were conducted in Africa, 3 in Europe, 3 in the Americas, and 2 included sites in multiple continents. According to the NMA, 6 to 12 months of isoniazid were no more efficacious in preventing microbiologically confirmed TB than rifamycin-containing regimens (incidence rate ratio [IRR] 1.0, 95% CI 0.8 to 1.4, p = 0.8); however, 6 to 12 months of isoniazid were associated with a higher incidence of all-cause mortality (IRR 1.6, 95% CI 1.2 to 2.0, p = 0.02) and a higher risk of grade 3 or higher hepatotoxicity (risk difference [RD] 8.9, 95% CI 2.8 to 14.9, p = 0.004). Finally, shorter regimens were associated with higher completion rates relative to longer regimens, and we did not find statistically significant differences in the risk of drug-resistant TB between regimens. Study limitations include potential confounding due to differences in posttreatment follow-up time and TB incidence in the study setting on the estimates of incidence of TB or all-cause mortality, as well as an underrepresentation of pregnant women and children., Conclusions: Rifamycin-containing regimens appear safer and at least as effective as isoniazid regimens in preventing TB and death and should be considered part of routine care in PLHIV. Knowledge gaps remain as to which specific rifamycin-containing regimen provides the optimal balance of efficacy, completion, and safety., Competing Interests: The authors have declared that no competing interests exist.

Opioids are one of the most prescribed classes of analgesic medications. Their narrow therapeutic index and metabolism through cytochrome p450 (CYP) enzymes can result in a drug interaction when used concomitantly with rifamycins. In clinical scenarios where concurrent therapy with an opioid and a rifamycin occurs, there is no standardized guidance for managing the interaction. The objective of this review was to examine literature which evaluates the concomitant use of opioids and rifamycins with clinically relevant CYP-inducing properties. A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria was performed. PubMed, Scopus, and OVID Embase were queried for studies from database inception to January 2020 related to rifamycin and opioid medications. Only full-text, peer-reviewed, English language articles addressing clinical outcomes from concomitant rifamycin and opioid therapy were included. The review isolated 12 articles for data extraction from an original 2260 citations identified. Rifampin (11; 92%) and rifabutin (2; 17%) were the rifamycins studied along with seven different opioids. Decreased effect of opioids with concomitant rifampin therapy manifested as withdrawal in numerous patients on methadone and a decreased analgesic effect from tramadol, morphine, and, most notably, oxycodone. Only the combinations of rifampin with buccal fentanyl and rifabutin with buprenorphine and methadone were found to have no clinically measurable interaction. Available literature suggests that a decrease in opioid clinical effects is appreciated with concomitant rifamycin therapy. Further research is needed to focus on specific mitigation strategies beyond opioid agent selection, such as dosing adjustment recommendations., (© 2021 Pharmacotherapy Publications, Inc.)

Background: Globally, drug resistant tuberculosis (DR-TB) continues to be a public health threat. Nigeria, which accounts for a significant proportion of the global burden of rifampicin/multi-drug resistant-TB (RR/MDR-TB) had a funding gap of $168 million dollars for TB treatment in 2018. Since 2010, Nigeria has utilized five different models of care for RR/MDR-TB (Models A-E); Models A, B and C based on a standardized WHO-approved treatment regimen of 20-24 months, were phased out between 2015 and 2019 and replaced by Models D and E. Model D is a fully ambulatory model of 9-12 months during which a shorter treatment regimen including a second-line injectable agent is utilized. Model E is identical to Model D but has patients hospitalized for the first four months of care while Model F which is to be introduced in 2020, is a fully ambulatory, oral bedaquiline-containing shorter treatment regimen of 9-12 months. Treatment models for RR/MDR-TB of 20-24 months duration have had treatment success rates of 52-66% while shorter treatment regimens have reported success rates of 85% and above. In addition, replacing the second-line injectable agent in a shorter treatment regimen with bedaquiline has been found to further improve treatment success in patients with fluoroquinolone-susceptible RR/MDR-TB. Reliable cost data for RR/MDR-TB care are limited, specifically costs of models that utilize shorter treatment regimens and which are vital to guide Nigeria through the provision of RR/MDR-TB care at scale. We therefore conducted a cost analysis of shorter treatment regimens in use and to be used in Nigeria (Models D, E and F) and compared them to three models of longer duration utilized previously in Nigeria (Models A, B and C) to identify any changes in cost from transitioning from Models A-C to Models D-F and opportunities for cost savings., Methods: We obtained costs for TB diagnostic and monitoring tests, in-patient and out-patient care from a previous study, inflated these costs to 2019 NGN and then converted to 2020 USD. We obtained other costs from the average of six health facilities and drug costs from the global drug facility. We modeled treatment on strict adherence to two Nigerian National guidelines for programmatic and clinical management of drug-resistant tuberculosis., Results: We estimated that the total costs of care from the health sector perspective for Models D, E and F were $4,334, $7,705 and $3,420 respectively. This is significantly lower than the costs of Models A, B and C which were $14,781, $12, 113, $7,572 respectively., Conclusion: Replacing Models A-C with Models D and E reduced the costs of RR/MDR-TB care in Nigeria by approximately $5,470 (48%) per patient treated and transitioning from Models D and E to Model F would result in further cost savings of $914 to $4,285 (21 to 56%) for every patient placed on Model F. If the improved outcomes of patients managed using bedaquiline-containing shorter treatment regimens in other countries can be attained in Nigeria, Model F would be the recommended model for the scale up of RR/MDR-TB care in Nigeria., Competing Interests: The authors have declared that no competing interests exist.

Purpose of Review: With its impact on quality of life and increasing awareness, postinfectious irritable bowel syndrome (PI-IBS) is now gaining attention as one of the major health problems commonly encountered in gastrointestinal practice. Literature investigating the various pathogenic mechanisms involved is rapidly emerging. The objective of the current review is to provide an update on recent evidence published in the past 2 years describing advances in our understanding of the epidemiology, pathogenesis, diagnosis, and treatment of PI-IBS., Recent Findings: Significant proportion of research in the recent past was preclinical in nature. Epidemiological studies continue to highlight the risk of IBS after infection, with recent studies documenting postprotozoal effects. Advances in pathogenic mechanisms included clinical studies, which documented micro-RNA down-regulation and Peroxiredoxin-1 up-regulation in colonic mucosa of PI-IBS patients. Protease-activated receptor-2 (PAR-2) activation in PI-IBS mice models resulted in increase in epithelial permeability, mucosal inflammation, visceral hypersensitivity. Moxibustion and rifamycin reduced intestinal inflammation by inhibiting cytokine and chemokine release via different mechanisms. Miltefosine reduced mast cell degranulation and TRPV1 activation, thereby reducing visceral hypersensitivity., Summary: At present, generalization of limited diagnostic and therapeutic strategies across a heterogeneous prevalent patient population impedes the ability to provide effective personalized care in PI-IBS. Further development in pathogenesis discovery, diagnostic tool development are needed in order to design well tolerated and effective therapies that guide treatments based on distinct pathways of disease.

Mycobacterium xenopi is associated with the highest mortality among pulmonary nontuberculous mycobacterial (NTM) infections, but whether this is due to the infection or other factors is unclear. There is little information regarding outcomes among patients infected with M. xenopi versus other NTM species. We conducted a retrospective matched cohort study comparing M. xenopi pulmonary disease (Mx-PD) to M. avium complex (MAC)-PD. Patients were matched by sex, age, radiologic subtype, and presence of cavitation. Baseline clinical characteristics, treatment, and outcomes were compared using matched analyses. We identified 70 Mx-PD cases: 29 fibrocavitary-type, 28 nodular-bronchiectatic-type, and 13 unclassifiable-type CT patterns, mean (SD) age 63 (13) years, and 54.3% (n = 38) female. Median follow-up duration was longer in the Mx-PD cohort (1552 days versus 1035 days, p = 0.01). Symptoms, radiologic phenotype, and pulmonary function were similar between groups although the Charlson Comorbidity Index was numerically higher in Mx-PD patients (3.6 versus 3.2, p = 0.08). Rifamycins were used less frequently in Mx-PD (59.5% versus 85.7%, p = 0.02). Although combined clinical and radiologic improvement was similar between the groups, successful treatment was more common with Mx-PD (40.5% versus 16.7%, p = 0.02) owing to superior culture conversion (70.8% versus 33.3%, p = 0.0001). Mortality 24 months after initiation of treatment was numerically but not statistically greater in the Mx-PD cohort (20.4% versus 10.3%, p = 0.32). Among matched Mx-PD and MAC-PD patients, standard anti-mycobacterial treatment was significantly more likely to achieve culture conversion and successful treatment for Mx-PD patients. Mortality among Mx-PD patients was numerically, but not statistically higher, possibly explained by increased comorbidity burden., (Crown Copyright © 2020. Published by Elsevier Ltd. All rights reserved.)

TNP-2092 is a unique multitargeting drug conjugate with extremely low propensity for development of resistance. The in vitro activity of TNP-2092 against a panel of urease-producing bacteria was similar to that of rifaximin, a locally acting antibiotic approved for the treatment of hepatic encephalopathy, irritable bowel syndrome with diarrhea, and traveler's diarrhea. When given orally, TNP-2092 exhibited low absorption and the majority of compound was recovered in feces as parent. The impact of oral TNP-2092 on gut microbiota was investigated in rats. TNP-2092 was administered to rats by oral gavage for 7 days. Feces samples were collected and analyzed by 16S rRNA sequencing. Although the total amount of bacterial load appeared relatively unchanged before, during, and after treatment, significant changes in the relative abundance of certain gut bacteria at family and genus levels were observed. Some of the changes are known to be associated with improvement of symptoms associated with liver cirrhosis and hepatic encephalopathy. The observed effects of TNP-2092 on gut microbiota in rats were similar to those of rifaximin. In vivo , TNP-2092 demonstrated potent efficacy in a mouse Clostridium difficile infection model, superior to metronidazole and vancomycin, with no relapse observed after treatment. TNP-2092 is currently in clinical development for the treatment of symptoms associated with gastrointestinal and liver disorders.