Nontraditional Treatment of Hepatic Encephalopathy

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.

Efficacy of Rifaximin in Patients With Abdominal Bloating or Distension: A Systematic Review and Meta-analysis

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.

Diagnostic Performance of the ICD-10 Code K76.82 for Hepatic Encephalopathy in Patients With Cirrhosis

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.

The potential for development of clinically relevant microbial resistance to rifaximin-α: a narrative review

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.

Gut microbiota composition and diversity before, during, and two months after rifamycin-based tuberculosis preventive therapy

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.

Nanoscaled Discovery of a Shunt Rifamycin from Salinispora arenicola Using a Three-Color GFP-Tagged Staphylococcus aureus Macrophage Infection Assay

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.

Clinical Outcomes of Oral Zinc Therapy in Hepatic Encephalopathy Treatment

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.

Efficacy and Safety of Rifaximin in the Prevention of Recurrent Episodes of Hepatic Encephalopathy: A Systematic Review and Meta-analysis

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.

Add-on Therapeutic Effects of Rifaximin on Treatment-resistant Hepatic Encephalopathy

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.

Dosing of Rifaximin Soluble Solid Dispersion Tablets in Adults With Cirrhosis: 2 Randomized, Placebo-controlled Trials

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).

Systematic Review and Meta-Analysis on the Effects of Lactulose and Rifaximin on Patient-Reported Outcomes in Hepatic Encephalopathy

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.

Pregnancy in Women With HIV in a Tuberculosis Preventive Therapy Trial

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.

Testing and Treating Mycobacterium tuberculosis Infection

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.

Therapeutic efficacy of rifalazil (KRM-1648) in a M. ulcerans-induced Buruli ulcer mouse model

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.

Heretical thoughts into hepatic encephalopathy

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.

Is rifaximin better than nonabsorbable disaccharides in hepatic encephalopathy?: A meta-analysis

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.

Tuberculosis preventive therapy for people living with HIV: A systematic review and network meta-analysis

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.

Cost comparison of nine-month treatment regimens with 20-month standardized care for the treatment of rifampicin-resistant/multi-drug resistant tuberculosis in Nigeria

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.

Evaluation of a Dual-Acting Antibacterial Agent, TNP-2092, on Gut Microbiota and Potential Application in the Treatment of Gastrointestinal and Liver Disorders

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.

New Drugs 2020, part 2

This article reviews seven drugs recently approved by the FDA, including indications, precautions, adverse reactions, and nursing considerations.

New opportunities in tuberculosis prevention: implications for people living with HIV

INTRODUCTION

Tuberculosis (TB) is a leading cause of mortality among people living with HIV (PLHIV). An invigorated global END TB Strategy seeks to increase efforts in scaling up TB preventive therapy (TPT) as a central intervention for HIV programmes in an effort to contribute to a 90% reduction in TB incidence and 95% reduction in mortality by 2035. TPT in PLHIV should be part of a comprehensive approach to reduce TB transmission, illness and death that also includes TB active case-finding and prompt, effective and timely initiation of anti-TB therapy among PLHIV. However, the use and implementation of preventive strategies has remained deplorably inadequate and today TB prevention among PLHIV has become an urgent priority globally.

DISCUSSION

We present a summary of the current and novel TPT regimens, including current evidence of use with antiretroviral regimens (ART). We review challenges and opportunities to scale-up TB prevention within HIV programmes, including the use of differentiated care approaches and demand creation for effective TB/HIV services delivery. TB preventive vaccines and diagnostics, including optimal algorithms, while important topics, are outside of the focus of this commentary.

CONCLUSIONS

A number of new tools and strategies to make TPT a standard of care in HIV programmes have become available. The new TPT regimens are safe and effective and can be used with current ART, with attention being paid to potential drug-drug interactions between rifamycins and some classes of antiretrovirals. More research and development is needed to optimize TPT for small children, pregnant women and drug-resistant TB (DR-TB). Effective programmatic scale-up can be supported through context-adapted demand creation strategies and the inclusion of TPT in client-centred services, such as differentiated service delivery (DSD) models. Robust collaboration between the HIV and TB programmes represents a unique opportunity to ensure that TB, a preventable and curable condition, is no longer the number one cause of death in PLHIV.

Shorter-course treatment for Mycobacterium ulcerans disease with high-dose rifamycins and clofazimine in a mouse model of Buruli ulcer

Starting in 2004, the standard regimen for treatment of Buruli ulcer (BU) recommended by the World Health Organization has been daily treatment for eight weeks with rifampin (RIF) and streptomycin. Based on recent clinical trials, treatment with an all-oral regimen of RIF and clarithromycin (CLR) may be an effective alternative. With the achievement of an all-oral regimen, a new goal is to find a regimen that can shorten the duration of treatment without compromising efficacy. We recently observed that increasing the dose of RIF from the standard 10 mg/kg dose to 20 or 40 mg/kg, or replacing RIF with the more potent long-acting rifamycin, rifapentine (RPT) at 10 mg/kg or 20 mg/kg increased the bactericidal activity of the RIF+CLR regimen in a mouse model of BU. We also recently showed that replacing CLR with clofazimine(CFZ) at 25 mg/kg may have greater sterilizing activity than the RIF+CLR regimen. Here, we demonstrate that combining high-dose rifamycins with CFZ at a lower dose of 12.5 mg/kg results in similar reductions in swelling, bacterial burden and mycolactone concentrations in mouse footpads compared to the standard regimens and more rapid sterilization of footpads as determined by the proportions of footpads harboring viable bacteria three months after completion of treatment. The potential of these high-dose rifamycin and CFZ combinations to shorten BU treatment to four weeks warrants evaluation in a clinical trial.

Buruli ulcer, a neglected tropical skin disease caused by Mycobacterium ulcerans, is treatable since 2004 with antibiotics instead of surgery. Treatment with either rifampin plus streptomycin or, more recently, rifampin plus clarithromycin requires taking the drugs daily for 8 weeks. Streptomycin is administered by injection and may result in hearing loss. Clarithromycin often causes gastrointestinal discomfort. Our goal is to identify a regimen that is both shorter and associated with fewer side effects. Rifampin, previously an expensive drug, is well tolerated not only at the standard dose of 10 mg/kg but at doses of 20 and 40 mg/kg. The related rifamycin, rifapentine, has a longer half-life and is also well tolerated. We tested in a mouse model of Buruli ulcer whether higher doses of these rifamycins together with clofazimine, a drug that has transient skin pigmentation side effects but no toxicities, could effectively reduce lesion size, the number of bacteria, and production of the mycolactone toxin, in a shorter time than that for the existing drug regimens. We found that treatment for 4 weeks with a high dose rifamycin plus clofazimine is as effective as 8 weeks of the current standard regimens of rifampin plus streptomycin or rifampin plus clarithromycin.

Ciprofloxacin Ophthalmic Solution versus Rifamycin Ophthalmic Solution for the Treatment of Conjunctivitis and Blepharitis

The efficacy and safety of ciprofloxacin (0.3%) ophthalmic solution and rifamycin (1%) ophthalmic solution for the treatment of bacterial conjunctivitis and blepharitis was compared in this randomized, double-masked, parallel-group study. Forty-one patients, 19 on ciprofloxacin and 22 on rifamycin, were culture-positive on admission and evaluated for efficacy. There was clinical improvement in more than 90% of patients in each group at the end of the seven-day treatment period. However, clinical cure rates on day 7 appeared to be higher with ciprofloxacin (53%) than rifamycin (23%; p = 0.061, Mann-Whitney test). Bacteriological eradication rates were comparable: the infecting organisms were eradicated in 68% of patients on ciprofloxacin and 77% with rifamycin. There were no serious adverse reactions to either treatment. One patient in each group was withdrawn on account of a mild allergy. In conclusion, topical ciprofloxacin was effective and well tolerated and would be a particularly useful agent for the treatment of bacterial conjunctivitis and blepharitis.

Update on the Therapeutic Management of Hepatic Encephalopathy

PURPOSE OF REVIEW

Hepatic encephalopathy (HE) is a common and devastating complication to chronic liver disease. In this paper, we summarize the latest research and evidence of both conventional and up-coming treatments.

RECENT FINDINGS

Meta-analyses report beneficial effects of lactulose, branched-chain amino acids, rifaximin, and to some degree L-ornithine L-aspartate on the manifestations of HE in patients with cirrhosis, and generally the numbers needed to treat are low. Recent studies on newer HE treatments including ornithine phenylacetate, spherical carbon, and fecal microbiota transplant also report potentially beneficial effects on HE manifestations. The conventional treatments benefit patients with HE. Newer treatments are under study and more research is needed for their validation.

Rifaximin ameliorates hepatic encephalopathy and endotoxemia without affecting the gut microbiome diversity

AIM

To determine the efficacy of rifaximin for hepatic encephalopathy (HE) with the linkage of gut microbiome in decompensated cirrhotic patients.

METHODS

Twenty patients (12 men and 8 women; median age, 66.8 years; range, 46-81 years) with decompensated cirrhosis (Child-pugh score > 7) underwent cognitive neuropsychological testing, endotoxin analysis, and fecal microbiome assessment at baseline and after 4 wk of treatment with rifaximin 400 mg thrice a day. HE was determined by serum ammonia level and number connection test (NCT)-A. Changes in whole blood endotoxin activity (EA) was analyzed by endotoxin activity assay. Fecal microbiome was assessed by 16S ribosome RNA (rRNA) gene sequencing.

RESULTS

Treatment with rifaximin for 4 wk improved hyperammonemia (from 90.6 ± 23.9 μg/dL to 73.1 ± 33.1 μg/dL; P < 0.05) and time required for NCT (from 68.2 ± 17.4 s to 54.9 ± 20.3 s; P < 0.05) in patients who had higher levels at baseline. Endotoxin activity was reduced (from 0.43 ± 0.03 to 0.32 ± 0.09; P < 0.05) in direct correlation with decrease in serum ammonia levels (r = 0.5886, P < 0.05). No statistically significant differences were observed in the diversity estimator (Shannon diversity index) and major components of the gut microbiome between the baseline and after treatment groups (3.948 ± 0.548 at baseline vs 3.980 ± 0.968 after treatment; P = 0.544), but the relative abundances of genus Veillonella and Streptococcus were lowered.

CONCLUSION

Rifaximin significantly improved cognition and reduced endotoxin activity without significantly affecting the composition of the gut microbiome in patients with decompensated cirrhosis.

Symptom Severity Following Rifaximin and the Probiotic VSL#3 in Patients with Chronic Pelvic Pain Syndrome (Due to Inflammatory Prostatitis) Plus Irritable Bowel Syndrome

This study investigated the effects of long-term treatment with rifaximin and the probiotic VSL#3 on uro-genital and gastrointestinal symptoms in patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) plus diarrhoea-predominant irritable bowel syndrome (D-IBS) compared with patients with D-IBS alone. Eighty-five patients with CP/CPPS (45 with subtype IIIa and 40 with IIIb) plus D-IBS according to the Rome III criteria and an aged-matched control-group of patients with D-IBS alone (n = 75) received rifaximin and VSL#3. The primary endpoints were the response rates of IBS and CP/CPPS symptoms, assessed respectively through Irritable Bowel Syndrome Severity Scoring System (IBS-SSS) and The National Institute of Health Chronic Prostatitis Symptom Index (NIH-CPSI), and performed at the start of therapy (V0) and three months after (V3). In IIIa prostatitis patients, the total NIH-CPSI scores significantly (p < 0.05) decreased from a baseline mean value of 21.2 to 14.5 at V3 , as did all subscales, and in the IIIb the total NIH-CPSI score also significantly decreased (from 17.4 to 15.1). Patients with IBS alone showed no significant differences in NIH-CPSI score. At V3, significantly greater improvement in the IBS-SSS and responder rate were found in IIIa patients. Our results were explained through a better individual response at V3 in IIIa prostatitis of urinary and gastrointestinal symptoms, while mean leukocyte counts on expressed prostate secretion (EPS) after prostate massage significantly lowered only in IIIa cases.

Comparison of Rifaximin Plus Lactulose with the Lactulose Alone for the Treatment of Hepatic Encephalopathy

INTRODUCTION

Hepatic encephalopathy is challenging complication of liver dysfunction. Therapeutic treatment options for hepatic encephalopathy are currently limited and have appreciable risks and benefits associated with their use. Rifaximin is a novel anti microbiological agent with wide spectrum of activity that has shown promise as an alternative option for hepatic encephalopathy.

AIMS AND OBJECTIVE

The present study was undertaken to compare the effectiveness of Rifaximin and Lactulose as a combination vs Lactulose alone, to compare the adverse effects and to study the rapidity of therapeutic effects of Rifaximin and Lactulose.

METHODS

It was a prospective observational study. 60 patients suffering from hepatic encephalopathy (HE) were studied. Patients were investigated and treated as per treating physician's decision. At the time of analysis, patients were divided into 2 groups, Rifaximin group who received Rifaximin+Lactulose (R+L) and Lactulose group(L), who received Lactulose only. Parameters such as mental status grade, Asterixis grade, Serum Ammonia grade, Number Connection Test grade (NCT grade), Hepatic Encephalopathy Index (HE index) were evaluated and compared in both groups. Clinical efficacy was determined using HE index improvement. Primary end points were decrease in HE index and reversal of HE grades. Secondary end points were mortality from HE or any other cause, decrease in mental status grade, asterixis grade, serum Ammonia grade, NCT grade.

RESULTS

Out of 60 patients, 32 received Rifaximin+Lactulose combination and 28 patients received Lactulose alone. Mean Child-Turcotte-Pugh score (CTP score) was 10.6 in R+L group and 10.32 in L group. There was statistically significant improvement in mental status grade, Asterixis grade, Serum Ammonia grade, NCT grade, Hepatic encephalopathy index in both groups, p value <0.05 but no statistically significant difference between improvement in mental status grade, Asterixis grade, Serum Ammonia grade, NCT grade, HE index between the two groups. Rifaximin + Lactulose combination was effective in 31 out of 32 i.e.96.87% and Lactulose alone in 24 out of 28 patients, i.e. in 85.71%, which is not statistically different, p=0.3251.

DISCUSSION

Rifaximin+ Lactulose combination is not superior to Lactulose alone in treatment of refractory hepatic encephalopathy. Addition of Rifaximin may help in the treatment of refractory hepatic encephalopathy.

CONCLUSIONS

Rifaximin + Lactulose combination is effective, but not superior to Lactulose alone in treatment of hepatic encephalopathy.

Eubiotic properties of rifaximin: Disruption of the traditional concepts in gut microbiota modulation

Antibiotics are usually prescribed to cure infections but they also have significant modulatory effects on the gut microbiota. Several alterations of the intestinal bacterial community have been reported during antibiotic treatment, including the reduction of beneficial bacteria as well as of microbial alpha-diversity. Although after the discontinuation of antibiotic therapies it has been observed a trend towards the restoration of the original condition, the new steady state is different from the previous one, as if antibiotics induced some kind of irreversible perturbation of the gut microbial community. The poorly absorbed antibiotic rifaximin seem to be different from the other antibiotics, because it exerts non-traditional effects additional to the bactericidal/bacteriostatic activity on the gut microbiota. Rifaximin is able to reduce bacterial virulence and translocation, has anti-inflammatory properties and has been demonstrated to positively modulate the gut microbial composition. Animal models, culture studies and metagenomic analyses have demonstrated an increase in Bifidobacterium, Faecalibacterium prausnitzii and Lactobacillus abundance after rifaximin treatment, probably consequent to the induction of bacterial resistance, with no major change in the overall gut microbiota composition. Antibiotics are therefore modulators of the symbiotic relationship between the host and the gut microbiota. Specific antibiotics, such as rifaximin, can also induce eubiotic changes in the intestinal ecosystem; this additional property may represent a therapeutic advantage in specific clinical settings.

Dietary and pharmacological treatment of abdominal pain in IBS

This review introduces the principles of visceral sensation and appraises the current approaches to management of visceral pain in functional GI diseases, principally IBS. These approaches include dietary measures including fibre supplementation, low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet, and pharmacological approaches such as antispasmodics, peppermint oil, antidepressants (tricyclic agents, selective serotonin reuptake inhibitors), 5-HT₃ receptor antagonists (alosetron, ondansetron, ramosetron), non-absorbed antibiotic (rifaximin), secretagogues (lubiprostone, linaclotide), μ-opioid receptor (OR) and κ-OR agonist, δ-OR antagonist (eluxadoline), histamine H1 receptor antagonist (ebastine), neurokinin-2 receptor antagonist (ibodutant) and GABAergic agents (gabapentin and pregabalin). Efficacy and safety are discussed based on pivotal trials or published systematic reviews and meta-analysis, expressing ORs or relative risks and their 95% CIs. Potential new approaches may be based on recent insights on mucosal expression of genes, and microRNA and epigenetic markers in human biopsies and in animal models of visceral hypersensitivity.The objectives of this review are to appraise the physiology and anatomy of gut sensation and the efficacy in the relief of visceral pain (typically in IBS) of several classes of therapies. These include fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and different classes of medications (box 1). Box 1Classes of pharmacological agents for visceral painAntidepressants (tricyclic agents, selective serotonin reuptake inhibitors)Peppermint oil5-HT₃ receptor antagonists (alosetron, ondansetron, ramosetron)Non-absorbed antibiotic (rifaximin)Secretagogues (lubiprostone, linaclotide)μ-Opioid receptor (OR) and κ-OR agonist and δ-OR antagonist (eluxadoline)Histamine H1 receptor antagonist (ebastine)Neurokinin-2 receptor antagonist (ibodutant)GABAergic agents (gabapentin and pregabalin).

The impact of rifaximin in the prevention of bacterial infections in cirrhosis

OBJECTIVE

Bacterial infections are a leading factor in the progression from compensated to decompensated cirrhosis, with consequent worsening of the prognosis, and concerted efforts have been made to reduce infections and improve the survival rate of these patients. We retrospectively investigated the rate of infections in hospitalized cirrhotic patients under treatment with rifaximin.

PATIENTS AND METHODS

We enrolled 649 patients whose clinical and personal data, prescribed therapy, microbiological findings and laboratory tests were collected from previous discharge letters and our institution database. The efficacy of rifaximin in preventing several types infection was evaluated by comparing outcomes for rifaximin-treated patients vs patients receiving no antibiotic treatment.

RESULTS

The risk of developing selected bacterial infections was significantly lower in patients treated with rifaximin (OR 0.29; 95% CI 0.20-0.40, p < 0.001).

CONCLUSIONS

Continuous treatment with rifaximin may prevent bacterial infections in cirrhotic patients.

Prospective Clinical Trial of Rifaximin Therapy for Patients With Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is a rare, chronic, cholestatic liver disease in which emerging data suggest that oral antibiotics may offer therapeutic effects. We enrolled patients with PSC in a 12-week, open-label pilot study to investigate the efficacy and safety of 550 mg of oral rifaximin twice daily. The primary end point was serum alkaline phosphatase (ALK) at 12 weeks. Secondary end points included (1) serum bilirubin, gamma-glutamyl transpeptidase, and Mayo PSC risk score; (2) fatigue impact scale, chronic liver disease questionnaire, and short form health survey (SF-36) scores; and (3) adverse effects (AEs). Analyses were performed with nonparametric tests. Sixteen patients were enrolled, among whom the median age was 40 years; 13 (81%) were male, 13 had inflammatory bowel disease, and baseline ALK was 342 IU/mL (interquartile range, 275-520 IU/mL). After 12 weeks of treatment, there were no significant changes in ALK (median increase of 0.9% to 345 IU/mL; P = 0.47) or any of the secondary biochemical end points (all P > 0.05). Similarly, there were no significant changes in fatigue impact scale, chronic liver disease questionnaire, or SF-36 scores (all P > 0.05). Three patients withdrew from the study due to AEs; 4 others reported mild AEs but completed the study. In conclusion, although some antibiotics may have promise in treating PSC, oral rifaximin, based on the results herein, seems inefficacious for this indication. Future studies are needed to understand how the antimicrobial spectra and other properties of antibiotics might determine their utility in treating PSC.

New treatment options for irritable bowel syndrome with predominant diarrhea

PURPOSE OF REVIEW

Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder with negative impact on quality of life and it represents a substantial economic burden on healthcare cost. The medical management of IBS remains largely symptomatic. This review provides an update related to the most recently published diagnostic Rome IV criteria for IBS and clinical trial data for novel treatment modalities in IBS targeting the peripheral opioid receptors of the enteric nervous system and the gut microbiota.

RECENT FINDINGS

The new Rome IV criteria define functional gastrointestinal disorders as disorders of the gut-brain interaction. In addition to previously introduced pharmacological treatment modalities for IBS with constipation (IBS-C) with synthetic peptides and small molecules targeting gastrointestinal receptors and ion channels, the newly Food and Drug Administration-approved mixed peripheral opioid receptor agonist/antagonist eluxadoline and the nonabsorbable antibiotic rifaximin demonstrate efficacy and safety in the treatment of IBS with predominant diarrhea (IBS-D).

SUMMARY

Diagnostic criteria for functional gastrointestinal disorders, including IBS, have been revised in Rome IV and are defined as gut-brain disorders. The mixed peripheral opioid receptor agonist/antagonist eluxadoline and the antibiotic rifaximin have been recently Food and Drug Administration approved for the treatment of diarrhea-predominant IBS (IBS-D) with proven efficacy and acceptable side-effect profiles.

Posterior reversible encephalopathy syndrome in alcoholic hepatitis: Hepatic encephalopathy a common theme

Posterior reversible encephalopathy syndrome (PRES) is a neuro-radiologic diagnosis that has become more widely recognized and reported over the past few decades. As such, there are a number of known risk factors that contribute to the development of this syndrome, including volatile blood pressures, renal failure, cytotoxic drugs, autoimmune disorders, pre-eclampsia, and eclampsia. This report documents the first reported case of PRES in a patient with severe alcoholic hepatitis with hepatic encephalopathy and delves into a molecular pathophysiology of the syndrome.

Rifaximin Decreases the Incidence and Severity of Acute Kidney Injury and Hepatorenal Syndrome in Cirrhosis

BACKGROUND

While the effects of rifaximin have been shown to be protective against acute kidney injury (AKI) and hepatorenal syndrome (HRS) in alcohol-induced cirrhosis, its long-term effects on the renal function of other cirrhotic patients are unknown.

AIM

To examine the long-term effects of rifaximin on the renal function of patients with cirrhosis from various etiologies.

METHODS

In a retrospective study, we examined cirrhotic patients at the University of Chicago Liver Clinic from January 1, 2011, to December 31, 2014. The study enrolled patients on rifaximin for ≥90 days, who were then matched by age, gender, and MELD score to a control group. Patients with malignancy and renal replacement therapy (RRT) at baseline were excluded. Data were censored at the last follow-up, termination of rifaximin therapy, initiation of RRT, death, or liver transplant.

RESULTS

Eighty-eight rifaximin cases were identified and matched to 88 control cases. Baseline characteristics were similar, with the exceptions of more prevalent long-term midodrine use (≥90 days) (17.0 vs 4.5 %, p = 0.01) and baseline ascites (37.5 vs 23.8 %, p = 0.05) in the rifaximin group. There was no difference in the frequency of infections, deaths, liver transplants, or hospitalizations. After controlling for cofounders, the incidence rate ratio of AKI (IRR 0.71, p = 0.02) and HRS (IRR 0.21, p = 0.02), as well as the risk of requiring RRT (OR 0.23, p = 0.01), was lower in the rifaximin group.

CONCLUSIONS

Long-term use of rifaximin is associated with a decrease incidence of AKI and HRS and a decrease risk of requiring RRT in a general population of cirrhotic patients.

Emerging Therapies in the Treatment of Clostridium difficile–Associated Disease

Objective:

To describe emergent therapies, such as rifaximin, nitazoxanide, intravenous immunoglobulin (IVIG), tinidazole, tolevamer, and the possible use of a vaccine, in Clostridium difficile–associated disease (CDAD), one of the most common causes of diarrhea in hospitalized adults in North America.

Data Sources:

A literature search was performed using MEDLINE (1996-October 2006), PubMed (1996–October 2006), abstracts from Infectious Diseases Society of America (September 2006) and International Conference on Antimicrobial Agents and Chemotherapy (September 2006), Internet (October 2006), Genzyme product Web site (October 2006), and Romark Laboratories Web site (October 2006) using the terms Clostridium difficile, rifaximin, nitazoxanide, intravenous immunoglobulin, tolevamer, vaccine, and tinidazole.

Study Selection and Data Extraction:

Data presented in this article were selected based on clinical relevance and power of the studies. In vivo and in vitro studies supporting the use of drugs available for treatment of refractory CDAD were reviewed. Some of the information on new and emerging modalities was also included, although there were limited published data available.

Data Synthesis:

Clinical trials evaluating the use of nitazoxanide and tolevamer for the treatment of CDAD have been published. Tinidazole use is based on structural similarities to metronidazole; however, clinical trials have not been conducted and the cost of this agent may be a limiting factor. The use of rifaximin and IVIG will require randomized clinical trials to establish their place in therapy. Limited information in the literature suggests that a vaccine may be effective for CDAD prevention.

Conclusions:

CDAD is a debilitating disease with increasing treatment failure rates and recurrences using standard therapies. Clinicians need to look at other options to expand the available treatment arsenal in addition to placing a greater emphasis on prevention.

Use of rifaximin in gastrointestinal and liver diseases

Rifaximin is a broad spectrum oral antibiotic with antimicrobial activity against Gram-positive and Gram-negative aerobic and anaerobic bacteria. It is poorly absorbed and thus has a highly favorable safety profile. Rifaximin has been shown to be effective in the treatment of traveler’s diarrhea, functional bloating and irritable bowel syndrome, small bowel bacterial overgrowth and in the prevention of recurrent overt hepatic encephalopathy. In addition, there is emerging evidence for a possible beneficial effect of rifaximin in the treatment of uncomplicated diverticular disease and in the prevention of recurrent diverticulitis. The use of rifaximin is associated with a low incidence of development, or persistence of spontaneous bacterial mutants. Moreover, the development of important drug resistance among extra-intestinal flora during rifaximin therapy is unlikely because of minimal systemic absorption and limited cross-resistance of rifaximin with other antimicrobials. This review addresses the current and emerging role of rifaximin in the treatment of gastrointestinal and liver disorders.

Hepatic encephalopathy for the hospitalist

The care of patients with advanced liver disease is often complicated by episodes of acute decline in alertness and cognition, termed hepatic encephalopathy (HE). Hospitalists must be familiar with HE, as it is a common reason for hospitalization in this population and is associated with significantly increased mortality. This narrative review addresses common issues related to diagnosis and classification, precipitants, inpatient management, and transitions of care for patients with HE. The initial presentation can be variable, and HE remains a clinical diagnosis. The spectrum of HE manifestations spans from mild, subclinical cognitive deficits to overt coma. The West Haven scoring system is the most widely used classification system for HE. Various metabolic insults may precipitate HE, and providers must specifically seek to rule out infection and bleeding in cirrhotic patients presenting with altered cognition. This is consistent with the 4-pronged approach of the American Association for the Study of Liver Disease practice guidelines. Patients with HE are typically treated primarily with nonabsorbable disaccharide laxatives, often with adjunctive rifaximin. The evidence for these agents is discussed, and available support for other treatment options is presented. Management issues relevant to general hospitalists include those related to acute pain management, decisional capacity, and HE following transjugular intrahepatic portosystemic shunt placement. These issues are examined individually. Successfully transitioning patients recovering from HE to outpatient care requires open communication with multiple role players including patients, caregivers, and outpatient providers. Journal of Hospital Medicine 2016;11:591-594. © 2016 Society of Hospital Medicine.

Novel prevention strategies for bacterial infections in cirrhosis

INTRODUCTION

Bacterial infections are a serious complication of cirrhosis, as they can lead to decompensation, multiple organ failure, and/or death. Preventing infections is therefore very relevant. Because gut bacterial translocation is their main pathogenic mechanism, prevention of infections is mostly based on the use of orally administered poorly absorbed antibiotics such as norfloxacin (selective intestinal decontamination). However, antibiotic prophylaxis leads to antibiotic resistance, limiting therapy and increasing morbidity and mortality. Prevention of bacterial infections in cirrhosis should therefore move away from antibiotics.

AREAS COVERED

This review focuses on various potentially novel methods to prevent infections in cirrhosis focusing on non-antibiotic strategies. The use of probiotics, nonselective intestinal decontamination with rifaximin, prokinetics and beta-blockers or fecal microbiota transplant as means of targeting altered gut microbiota, bile acids and FXR agonists are all potential alternatives to selective intestinal decontamination. Prokinetics and beta-blockers can improve intestinal motility, while bile acids and FXR agonists help by improving the intestinal barrier. Finally, granulocyte colony stimulating factor (G-CSF) and statins are emerging therapeutic strategies that may improve immune dysfunction in cirrhosis.

EXPERT OPINION

Evidence for these strategies has been restricted to animal studies and proof-of concept studies but we expect this to change in coming years.

Rifaximin for Irritable Bowel Syndrome: A Meta-Analysis of Randomized Placebo-Controlled Trials

The current treatments for irritable bowel syndrome (IBS) are suboptimal. The findings of previous studies of rifaximin treatment for IBS may have differed due to variations in study design. Our study aimed to determine the therapeutic and adverse effects of rifaximin treatment for IBS based on a meta-analysis of published randomized controlled trials (RCTs). We searched the MEDLINE, EMBASE, EBSCO, Springer, Ovid, and Cochrane Library databases for RCTs investigating the effects of rifaximin on IBS. Data from each selected RCT was evaluated individually based on an intention-to-treat analysis, and a meta-analysis was performed in which the odds ratios (ORs) and 95% confidence intervals (CIs) of clinical outcomes and adverse events were calculated using fixed-effects models. Four eligible studies were identified. Overall relief of IBS symptoms in the rifaximin groups was greater than that in the placebo groups at the ends of both the treatment and follow-up periods (OR = 1.19; 95% CI: 1.08-1.32 and OR = 1.36; 95% CI: 1.18-1.58, respectively, P < 0.05 for both). Significant relief of abdominal distention was observed at the follow-up endpoint (OR = 1.69; 95% Cl: 1.27-2.23; P < 0.05), but not at the treatment endpoint (OR = 1.19; 95% CI: 0.96-1.49; P > 0.05). Abdominal pain (OR = 1.01; 95% CI: 0.98-1.03; P > 0.05), nausea (OR = 1.00; 95% CI: 0.98-1.02; P > 0.05), vomiting (OR: 0.99; 95% CI: 0.98-1.01; P > 0.05), and headache (OR = 1.01; 95% CI: 0.98-1.03; P > 0.05) did not differ significantly between the rifaximin and placebo groups. In the RCTs selected, our meta-analysis showed that the efficacy of rifaximin for the resolution of overall IBS symptoms was greater than that of the placebos, and that rifaximin was well-tolerated. The course of relief from abdominal distention in IBS patients treated with rifaximin may be delayed in some patients, compared with that of overall IBS symptom relief.

Treatment and prevention of pouchitis after ileal pouch-anal anastomosis for chronic ulcerative colitis

BACKGROUND

Pouchitis occurs in approximately 50% of patients following ileal pouch-anal anastomosis (IPAA) for chronic ulcerative colitis.

OBJECTIVES

The primary objective was to determine the efficacy and safety of medical therapies (including antibiotics, probiotics, and other agents) for prevention or treatment of acute or chronic pouchitis.

SEARCH METHODS

We searched MEDLINE, EMBASE and the Cochrane Library from inception to October 2014.

SELECTION CRITERIA

Randomized controlled trials of prevention or treatment of acute or chronic pouchitis in adults who underwent IPAA for ulcerative colitis were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently screened studies for eligibility, extracted data and assessed study quality. Methodological quality was assessed using the Cochrane risk of bias tool. The overall quality of the evidence supporting the outcomes was evaluated using the GRADE criteria. The primary outcome was the proportion of patients with clinical improvement or remission of pouchitis in patients with acute or chronic pouchitis, or the proportion of patients with no episodes of pouchitis after IPAA. The proportion of patients who developed at least one adverse event was a secondary outcome. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for each dichotomous outcome.

MAIN RESULTS

Thirteen studies (517 participants) were included in the review. Four studies assessed treatment of acute pouchitis. One study (16 participants) compared ciprofloxacin and metronidazole; another (26 participants) compared metronidazole to budesonide enemas; another (18 participants) compared rifaximin to placebo; and the fourth study (20 participants) compared Lactobacillus GG to placebo. Four studies assessed treatment of chronic pouchitis. One study (19 participants) compared glutamine to butyrate suppositories; another (40 participants) compared bismuth enemas to placebo; and two studies (76 participants) compared VSL#3 to placebo. Five studies assessed prevention of pouchitis. One study (40 participants) compared VSL#3 to placebo; another (28 participants) compared VLS#3 to no treatment; one study (184 participants) compared allopurinol to placebo; another (12 participants) compared the probiotic Bifidobacterium longum to placebo; and one study (38 participants) compared tinidazole to placebo. Three studies were judged to be of high quality. Two studies were judged to be low quality and the quality of the other studies was unclear. Treatment of acute pouchitis: The results of one small study (16 participants) suggest that ciprofloxacin may be more effective than metronidazole for the treatment of acute pouchitis. One hundred per cent (7/7) of ciprofloxacin patients achieved remission at two weeks compared to 33% (3/9) of metronidazole patients. A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was very low due to high risk of bias (no blinding) and very sparse data (10 events). There was no difference in the proportion of patients who had at least one adverse event (RR 0.18, 95% CI 0.01 to 2.98). Adverse events included vomiting, dysgeusia or transient peripheral neuropathy. There were no differences between metronidazole and budesonide enemas in terms of clinical remission, clinical improvement or adverse events. Adverse events included anorexia, nausea, headache, asthenia, metallic taste, vomiting, paraesthesia, and depression. There were no differences between rifaximin and placebo in terms of clinical remission, clinical improvement, or adverse events. Adverse events included diarrhea, flatulence, nausea, proctalgia, vomiting, thirst, candida, upper respiratory tract infection, increased hepatic enzyme, and cluster headache. There was no difference in clinical improvement between Lactobacillus GG and placebo. The results of these studies are uncertain due to very low quality evidence. Treatment of chronic pouchitis: A pooled analysis of two studies (76 participants) suggests that VSL#3 may be more effective than placebo for maintenance of remission. Eighty-five per cent (34/40) of VLS#3 patients maintained remission at 9 to 12 months compared to 3% (1/36) of placebo patients (RR 20.24, 95% CI 4.28 to 95.81). A GRADE analysis indicated that the quality of evidence supporting this outcome was low due to very sparse data (35 events). Adverse events included abdominal cramps, vomiting and diarrhea. There was no difference in effectiveness between glutamine and butyrate suppositories for maintenance of remission. There was no difference in clinical improvement or adverse event rates between bismuth carbomer foam enemas and placebo. Adverse events included diarrhea, worsening symptoms, cramping, sinusitis, and abdominal pain. The results of these studies are uncertain due to very low quality evidence. Prevention of pouchitis: The results of one small study (40 participants) suggest that VSL#3 may be more effective than placebo for prevention of pouchitis. Ninety per cent (18/20) of VSL#3 patients had no episodes of acute pouchitis during the 12 month study compared to 60% (12/20) of placebo patients (RR 1.50, 95% CI 1.02 to 2.21). A GRADE analysis indicated that the quality of evidence supporting this outcome was low due to very sparse data (30 events). Another small study (28 participants) found that VLS#3 was not more effective than no treatment for prevention of pouchitis. Bifidobacterium longum, allopurinol and tinidazole were not more effective than placebo for prevention of pouchitis. The results of these studies are uncertain due to very low quality evidence.

AUTHORS' CONCLUSIONS

For acute pouchitis, very low quality evidence suggests that ciprofloxacin may be more effective than metronidazole. For chronic pouchitis, low quality evidence suggests that VSL#3 may be more effective than placebo for maintenance of remission. For the prevention of pouchitis, low quality evidence suggests that VSL#3 may be more effective than placebo. Well designed, adequately powered studies are needed to determine the optimal therapy for the treatment and prevention of pouchitis.

Effect of rifaximin on gut microbiota composition in advanced liver disease and its complications

Liver cirrhosis is a paradigm of intestinal dysbiosis. The qualitative and quantitative derangement of intestinal microbial community reported in cirrhotic patients seems to be strictly related with the impairment of liver function. A kind of gut microbial “fingerprint”, characterized by the reduced ratio of “good” to “potentially pathogenic” bacteria has recently been outlined, and is associated with the increase in Model for End-Stage Liver Disease and Child Pugh scores. Moreover, in patients presenting with cirrhosis complications such as spontaneous bacterial peritonitis (SBP), hepatic encephalopathy (HE), and, portal hypertension intestinal microbiota modifications or the isolation of bacteria deriving from the gut are commonly reported. Rifaximin is a non-absorbable antibiotic used in the management of several gastrointestinal diseases. Beyond bactericidal/bacteriostatic, immune-modulating and anti-inflammatory activity, a little is known about its interaction with gut microbial environment. Rifaximin has been demonstrated to exert beneficial effects on cognitive function in patients with HE, and also to prevent the development of SBP, to reduce endotoxemia and to improve hemodynamics in cirrhotics. These results are linked to a shift in gut microbes functionality, triggering the production of favorable metabolites. The low incidence of drug-related adverse events due to the small amount of circulating drug makes rifaximin a relatively safe antibiotic for the modulation of gut microbiota in advanced liver disease.

[Role of rifaximin in the treatment of hepatic encephalopathy]

Hepatic encephalopathy (HE) is a frequent and serious complication of liver cirrhosis. In addition to correction of the precipitating factors, the most commonly used treatments are non-absorbable disaccharides and rifaximin. Many of the recommendations are based on current clinical practice and there are few randomized controlled trials. Currently, rifaximin should be initiated during an episode of EH if, after 24-48 hours of non-absorbable disaccharide therapy, there is no clinical improvement. In recurrent EH, it is advisable to add rifaximin in patients under non-absorbable disaccharide therapy who develop a new episode. Currently, standard treatment with rifaximin for minimal EH is not recommended. Rifaximin is effective in the acute treatment of overt encephalopathy and in preventing recurrence.

Practice parameters for the treatment of colonic diverticular disease: Italian Society of Colon and Rectal Surgery (SICCR) guidelines

The mission of the Italian Society of Colorectal Surgery (SICCR) is to optimize patient care. Providing evidence-based practice guidelines is therefore of key importance. About the present report it concernes the SICCR practice guidelines for the diagnosis and treatment of diverticular disease of the colon. The guidelines are not intended to define the sole standard of care but to provide evidence-based recommendations regarding the available therapeutic options.

Risk Factors for Acquired Rifamycin and Isoniazid Resistance: A Systematic Review and Meta-Analysis

BACKGROUND

Studies looking at acquired drug resistance (ADR) are diverse with respect to geographical distribution, HIV co-infection rates, retreatment status and programmatic factors such as regimens administered and directly observed therapy. Our objective was to examine and consolidate evidence from clinical studies of the multifactorial aetiology of acquired rifamycin and/or isoniazid resistance within the scope of a single systematic review. This is important to inform policy and identify key areas for further studies.

METHODS

Case-control and cohort studies and randomised controlled trials that reported ADR as an outcome during antitubercular treatment regimens including a rifamycin and examined the association of at least 1 risk factor were included. Post hoc, we carried out random effects Mantel-Haenszel weighted meta-analyses of the impact of 2 key risk factors 1) HIV and 2) baseline drug resistance on the binary outcome of ADR. Heterogeneity was assessed used I2 statistic. As a secondary outcome, we calculated median cumulative incidence of ADR, weighted by the sample size of the studies.

RESULTS

Meta-analysis of 15 studies showed increased risk of ADR with baseline mono- or polyresistance (RR 4.85 95% CI 3.26 to 7.23, heterogeneity I2 58%, 95% CI 26 to 76%). Meta-analysis of 8 studies showed that HIV co-infection was associated with increased risk of ADR (RR 3.02, 95% CI 1.28 to 7.11); there was considerable heterogeneity amongst these studies (I2 81%, 95% CI 64 to 90%). Non-adherence, extrapulmonary/disseminated disease and advanced immunosuppression in HIV co-infection were other risk factors noted. The weighted median cumulative incidence of acquired multi drug resistance calculated in 24 studies (assuming whole cohort as denominator, regardless of follow up DST) was 0.1% (5th to 95th percentile 0.07 to 3.2%).

CONCLUSION

Baseline drug resistance and HIV co-infection were significant risk factors for ADR. There was a trend of positive association with non-adherence which is likely to contribute to the outcome of ADR. The multifactorial aetiology of ADR in a programmatic setting should be further evaluated via appropriately designed studies.

[Options in the treatment of hepatic encephalopathy]

Hepatic encephalopathy is a result of insufficient liver function, with grave consequences for the patients. It is primarily caused by disturbed hepatic elimination of the neurotoxin, ammonia (NH3). Aside from dietetic measures, treatment rests on drugs designed to reduce the NH3 burden. The primary options, lactulose and the practically unabsorbable antibiotic rifaximin are suitable to decrease the bacterial NH3 generation in the intestine. Other antibiotics like neomycin at best have a place in acute treatment. L-ornithine-L-aspartate (LOLA) and branched-chain amino acids (valine, leucine, isoleucine) aim at supporting the scavenge of NH3 in glutamine; however, the final balance of this pathway is unfavourable. In addition, the constituents of LOLA enhance the capacity of the urea cycle and, ultimately, the elimination of NH3. As the evidence from available studies--is not unequivocal in each case, the current place of LOLA in treatment is that of an option for patients, who do not respond to standard therapy.