Rifaximin improves systemic hemodynamics and renal function in patients with alcohol-related cirrhosis and ascites

Future treatments of cirrhosis

Cirrhosis can be sub-classified in clinical stages with distinct differences in prognosis and can even be reversed in some cases with successful etiological treatment. In this article, we review potential future therapies of cirrhosis, mainly focusing in the expansion of indications of currently licensed drugs. We strongly advocate that future therapies should focus on preventing the advent of complications and further progression of liver disease and should involve both primary and secondary care physicians. Such strategies could be based on the combination of currently licensed, relatively safe and inexpensive drugs and such randomized controlled trials should be prioritized in patients with advanced liver disease. The paradigm should be similar to that of prevention in cardiovascular diseases and long-term follow-up trials are needed.

Systematic review with meta-analysis: the effects of rifaximin in hepatic encephalopathy

BACKGROUND

Rifaximin is recommended for prevention of hepatic encephalopathy (HE). The effects of rifaximin on overt and minimal HE are debated.

AIM

To perform a systematic review and meta-analysis of randomised controlled trials (RCTs) on rifaximin for HE.

METHODS

We performed electronic and manual searches, gathered information from the U.S. Food and Drug Administration Home Page, and obtained unpublished information on trial design and outcome measures from authors and pharmaceutical companies. Meta-analyses were performed and results presented as risk ratios (RR) with 95% confidence intervals (CI) and the number needed to treat. Subgroup, sensitivity, regression and sequential analyses were performed to evaluate the risk of bias and sources of heterogeneity.

RESULTS

We included 19 RCTs with 1370 patients. Outcomes were recalculated based on unpublished information of 11 trials. Overall, rifaximin had a beneficial effect on secondary prevention of HE (RR: 1.32; 95% CI 1.06-1.65), but not in a sensitivity analysis on rifaximin after TIPSS (RR: 1.27; 95% CI 1.00-1.53). Rifaximin increased the proportion of patients who recovered from HE (RR: 0.59; 95% CI: 0.46-0.76) and reduced mortality (RR: 0.68, 95% CI 0.48-0.97). The results were robust to adjustments for bias control. No small study effects were identified. The sequential analyses only confirmed the results of the analysis on HE recovery.

CONCLUSIONS

Rifaximin has a beneficial effect on hepatic encephalopathy and may reduce mortality. The combined evidence suggests that rifaximin may be considered in the evidence-based management of hepatic encephalopathy.

Liver cirrhosis

Cirrhosis is an increasing cause of morbidity and mortality in more developed countries, being the 14th most common cause of death worldwide but fourth in central Europe. Increasingly, cirrhosis has been seen to be not a single disease entity, but one that can be subclassified into distinct clinical prognostic stages, with 1-year mortality ranging from 1% to 57% depending on the stage. We review the current understanding of cirrhosis as a dynamic process and outline current therapeutic options for prevention and treatment of complications of cirrhosis, on the basis of the subclassification in clinical stages. The new concept in management of patients with cirrhosis should be prevention and early intervention to stabilise disease progression and to avoid or delay clinical decompensation and the need for liver transplantation. The challenge in the 21st century is to prevent the need for liver transplantation in as many patients with cirrhosis as possible.

Current treatment options for alcohol-related liver disease

PURPOSE OF REVIEW

The burden of alcohol on global health is increasing, and there is a strong relationship between population alcohol consumption and liver-related deaths. As alcohol-related liver disease (ArLD) often develops with no signs or symptoms, the prevention of liver disease relies on the recognition of harmful drinking and screening of those patients at risk for early markers of liver disease.

RECENT FINDINGS

A robust method of screening patients at risk of ArLD is essential. Once a patient develops ArLD, abstinence and early recognition of its complications are keys to improving outcomes. Corticosteroids remain the mainstay treatment in alcoholic hepatitis pending the results from large multicentre trials. More recently, there has been an increased interest in the use of rifaximin and albumin in various settings of ArLD.

SUMMARY

Advances in the treatment of ArLD and its complications, such as alcoholic hepatitis, will allow a greater proportion of patients chance for their liver to recover. However, new strategies to detect and intervene in those patients at higher risk of ArLD are likely to have the greatest overall impact.

Treatment options for covert hepatic encephalopathy

OPINION STATEMENT

The main issue with treating covert hepatic encephalopathy (HE) is to establish whether it is cost effective to reverse the neuropsychiatric abnormalities that define this mild form of HE. Until fairly recently, covert HE was rarely diagnosed, but advances in computerized psychometric testing have greatly simplified its detection. The many consequences of covert HE are now being identified, and most have been shown to be reversible with standard HE treatment. Perhaps the most enticing possibility will be the potential that standard HE therapies will postpone the onset of overt HE. This will require further evaluation with large placebo-controlled randomized trials.

Cirrhosis, bile acids and gut microbiota: unraveling a complex relationship

A picture is now starting to emerge regarding the liver-bile acid-microbiome axis. Increasing levels of the primary bile acid cholic acid (CA) causes a dramatic shift toward the Firmicutes, particularly Clostridium cluster XIVa and increasing production of the harmful secondary bile acid deoxycholic acid (DCA). During progression of cirrhosis, the microbiome, both through their metabolism, cell wall components (LPS) and translocation lead to inflammation. Inflammation suppresses synthesis of bile acids in the liver leading to a positive-feedback mechanism. Decrease in bile acids entering the intestines appears to favor overgrowth of pathogenic and pro-inflammatory members of the microbiome including Porphyromonadaceae and Enterobacteriaceae. Decreasing bile acid concentration in the colon in cirrhosis is also associated with decreases in Clostridium cluster XIVa, which includes bile acid 7α-dehydroxylating bacteria which produce DCA. Rifaximin treatment appears to act by suppressing DCA production, reducing endotoxemia and harmful metabolites without significantly altering microbiome structure. Taken together, the bile acid pool size and composition appear to be a major regulator of microbiome structure, which in turn appears to be an important regulator of bile acid pool size and composition. The balance between this equilibrium is critical for human health and disease.

Targeting the gut-liver axis in cirrhosis: antibiotics and non-selective β-blockers

The gut-liver axis in cirrhosis and portal hypertension is gaining increasing attention as a key pathophysiological mechanism responsible for progression of liver failure and development of complications such as spontaneous infections and hepatocellular carcinoma. Antibiotics and non-selective β-blockers (NSBB) intercept this axis and each drug has proven efficacy in clinical trials. A synergistic effect is a hitherto unproven possibility. There is an increasing body of evidence supporting improved outcome with expanded use of NSBB and antibiotic therapy beyond current indications. This review addresses the issue of pharmacological treatment of cirrhosis and portal hypertension with antibiotics and NSBB. We discuss their mechanism of action and suggest that combining the two treatment modalities could potentially reduce the risk of complications.

Abdominal contributions to cardiorenal dysfunction in congestive heart failure

Current pathophysiological models of congestive heart failure unsatisfactorily explain the detrimental link between congestion and cardiorenal function. Abdominal congestion (i.e., splanchnic venous and interstitial congestion) manifests in a substantial number of patients with advanced congestive heart failure, yet is poorly defined. Compromised capacitance function of the splanchnic vasculature and deficient abdominal lymph flow resulting in interstitial edema might both be implied in the occurrence of increased cardiac filling pressures and renal dysfunction. Indeed, increased intra-abdominal pressure, as an extreme marker of abdominal congestion, is correlated with renal dysfunction in advanced congestive heart failure. Intriguing findings provide preliminary evidence that alterations in the liver and spleen contribute to systemic congestion in heart failure. Finally, gut-derived hormones might influence sodium homeostasis, whereas entrance of bowel toxins into the circulatory system, as a result of impaired intestinal barrier function secondary to congestion, might further depress cardiac as well as renal function. Those toxins are mainly produced by micro-organisms in the gut lumen, with presumably important alterations in advanced heart failure, especially when renal function is depressed. Therefore, in this state-of-the-art review, we explore the crosstalk between the abdomen, heart, and kidneys in congestive heart failure. This might offer new diagnostic opportunities as well as treatment strategies to achieve decongestion in heart failure, especially when abdominal congestion is present. Among those currently under investigation are paracentesis, ultrafiltration, peritoneal dialysis, oral sodium binders, vasodilator therapy, renal sympathetic denervation and agents targeting the gut microbiota.

Antibiotics for the treatment of hepatic encephalopathy

The treatment of hepatic encephalopathy (HE) is complex and therapeutic regimens vary according to the acuity of presentation and the goals of therapy. Most treatments for HE rely on manipulating the intestinal milieu and therefore antibiotics that act on the gut form a key treatment strategy. Prominent antibiotics studied in HE are neomycin, metronidazole, vancomycin and rifaximin. For the management of the acute episode, all antibiotics have been tested. However the limited numbers studied, adverse effects (neomycin oto- and nephrotoxicity, metronidazole neurotoxicity) and potential for resistance emergence (vancomycin-resistant enterococcus) has limited the use of most antibiotics, apart from rifaximin which has the greatest evidence base. Rifaximin has also demonstrated, in conjunction with lactulose, to prevent overt HE recurrence in a multi-center, randomized trial. Despite its cost in the US, rifaximin may prove cost-saving by preventing hospitalizations for overt HE. In minimal/covert HE, rifaximin is the only systematically studied antibiotic. Rifaximin showed improvement in cognition, inflammation, quality-of-life and driving simulator performance but cost-analysis does not favor its use at the current time. Antibiotics, especially rifaximin, have a definite role in the management across the spectrum of HE.

Pathological bacterial translocation in cirrhosis: pathophysiology, diagnosis and clinical implications

Bacterial translocation (BT) is defined by the passage of viable indigenous bacteria from the intestinal lumen to mesenteric lymph nodes (MLNs) and other territories, and its diagnostic criteria rely on the isolation of viable bacteria in MLNs. Small intestinal overgrowth, increased intestinal permeability and immunological alterations are the main factors involved in its pathogenesis. BT is obviously difficult to identify in patients with cirrhosis, and alternative methods have been proposed instead. Bacterial DNA detection and species identification in serum or ascitic fluid has been proposed as a reliable marker of BT. Bacterial products, such as endotoxin, or bacterial DNA can translocate to extra-intestinal sites and promote an immunological response similar to that produced by viable bacteria. Therefore, pathological BT plays an important role in the pathogenesis of the complications of cirrhosis, not only in infections, but by exerting a profound inflammatory state and exacerbating the haemodynamic derangement. This may promote in turn the development of hepatorenal syndrome, hepatic encephalopathy and other portal hypertension-related complications. Therapeutic approaches for the prevention of BT in experimental and human cirrhosis are summarized. Finally, new investigations are needed to better understand the pathogenesis and consequences of translocation by viable bacteria (able to grow in culture), or non-viable BT (detection of bacterial fragments with negative culture) and open new therapeutic avenues in patients with cirrhosis.

Proton pump inhibitors are associated with a high rate of serious infections in veterans with decompensated cirrhosis

BACKGROUND

There is increasing evidence that proton pump inhibitors (PPIs) increase the rate of infections in patients with decompensated cirrhosis.

AIMS

To estimate the extent to which proton pump inhibitors (PPIs) increase the rate of infections among patients with decompensated cirrhosis.

METHODS

We conducted a retrospective propensity-matched new user design using US Veterans Health Administration data. Only decompensated cirrhotic patients from 2001 to 2009 were included. New PPI users after decompensation (n = 1268) were 1:1 matched to those who did not initiate gastric acid suppression. Serious infections, defined as infections associated with a hospitalisation, were the outcomes. These were separated into acid suppression-related (SBP, bacteremia, Clostridium difficile and pneumonia) and non-acid suppression-related. Time-varying Cox models were used to estimate adjusted hazard ratios (HR) and 95% CIs of serious infections. Parallel analyses were conducted with H2 receptor antagonists (H2RA).

RESULTS

More than half of persons with decompensated cirrhosis were new users of gastric acid suppressants, with most using PPIs (45.6%) compared with H2RAs (5.9%). In the PPI propensity-matched analysis, 25.3% developed serious infections and 25.9% developed serious infections in the H2RA analysis. PPI users developed serious infections faster than nongastric acid suppression users (adjusted HR: 1.66; 95% CI: 1.31–2.12). For acid suppression-related serious infections, PPI users developed the outcome at a rate 1.75 times faster than non-users (95% CI: 1.32–2.34). The H2RA findings were not statistically significant (HR serious infections: 1.59; 95% CI: 0.80–3.18; HR acid suppression-related infections: 0.92; 95% CI: 0.31–2.73).

CONCLUSION

Among patients with decompensated cirrhosis, proton pump inhibitors but not H2 receptor antagonists increase the rate of serious infections.