Secondary prophylaxis of hepatic encephalopathy: an open-label randomized controlled trial of lactulose versus placebo

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.

Lactulose, rifaximin or branched chain amino acids for hepatic encephalopathy: what is the evidence?

Hepatic encephalopathy (HE) is a serious complication of acute and chronic liver disease associated with severe morbidity and mortality. We performed updated random effects meta-analyses to evaluate the evidence for non-absorbable disaccharides (lactulose and lactitol), rifaximin and branched chain amino acids (BCAA). A meta-analysis of randomized trials showed that, compared with placebo or no intervention, non-absorbable disaccharides have beneficial effects on HE manifestations and prevention of HE episodes. The addition of rifaximin to non-absorbable disaccharides versus rifaximin alone was more beneficial than non-absorbable disaccharides used alone on both outcome measures. Likewise, a meta-analysis of randomised controlled trials found that oral BCAA supplements have beneficial effects on manifestations of HE compared with control supplements. The effect was found in a variety of clinical settings. No convincing effects of intravenous BCAA for episodic HE were identified. In conclusion, evidence-based treatment recommendations for patients with HE should include non-absorbable disaccharides combined with rifaximin or BCAA. Additional evidence is needed to evaluate the effect of combining all three interventions.

Encephalopathy and liver transplantation

Liver transplantation (LT) candidates experience frequently episodic or persistent hepatic encephalopathy. In addition, these patients can exhibit neurological comorbidities that contribute to cognitive impairment in the pre-transplant period. Assessment of the respective contribution of hepatic encephalopathy or comorbidities in the cognitive manifestations is critical to estimate the neurological benefits of restoring liver function. Magnetic resonance imaging and spectroscopy are useful to assess the impact of liver failure or comorbidities. This assessment is critical to decide liver transplant in difficult cases. In the early postoperative period, LT is commonly complicated by a confusional syndrome. The possible role of persisting hepatic encephalopathy in its development has not been clearly established. The origin is usually considered multifactorial and relates to complications following LT, such as infections, rejection, primary liver dysfunction, immunosuppressors, etc.… The diagnosis and treatment is based in the recognition of comorbidities and optimal care of metabolic disturbances. Several studies have demonstrated recovery of cognitive function after LT in patients that have exhibited hepatic encephalopathy. However, some deficits may persist specifically among patients with persistent HE. Other factors present before LT that contribute to a worse neuropsychological outcome after LT are diabetes mellitus and alcohol consumption. Long-term after LT, cognitive function may worsen in relation to vascular risk factors.

Disaccharides in the treatment of hepatic encephalopathy

Management of hepatic encephalopathy (HE) primarily involves avoidance of precipitating factors and administration of various ammonia-lowering therapies such as nonabsorbable disaccharides and antimicrobial agents like rifaximin. The nonabsorbable disaccharides which include lactulose and lactitol are considered the first-line therapy for the treatment of HE and minimal hepatic encephalopathy (MHE). Lactulose significantly improves cognitive function and health-related quality of life in patients with MHE. Lactitol is comparable to lactulose in the treatment of HE with fewer side effects. Lactulose has also shown to be effective in primary and secondary prophylaxis of HE. Disaccharides were found to be comparable to rifaximin in recent systemic reviews in the treatment of HE however conclusion was based on inclusion of some poor quality trials. Combination therapy of disaccharides either with rifaximin, L-ornithine L-aspartate,probiotics for the treatment of HE needs further validation in large studies.

Update on the management of cirrhosis - focus on cost-effective preventative strategies

Cirrhosis is a chronic liver disease stage that encompasses a variety of etiologies resulting in liver damage. This damage may induce secondary complications such as portal hypertension, esophageal variceal bleeding, spontaneous bacterial peritonitis, and hepatic encephalopathy. Screening for and management of these complications incurs substantial health care costs; thus, determining the most economical and beneficial treatment strategies is essential. This article reviews the economic impact of a variety of prophylactic and treatment regimens employed for cirrhosis-related complications. Prophylactic use of β-adrenergic blockers for portal hypertension and variceal bleeding appears to be cost-effective, but the most economical regimen for treatment of initial bleeding is unclear given that cost comparisons of pharmacologic and surgical regimens are lacking. In contrast, prophylaxis for spontaneous bacterial peritonitis cannot be recommended. Standard therapy for spontaneous bacterial peritonitis includes antibiotics, and the overall economic impact of these medications depends largely on their direct cost. However, the potential development of bacterial antibiotic resistance and resulting clinical failure should also be considered. Nonabsorbable disaccharides are standard therapies for hepatic encephalopathy; however, given their questionable efficacy, the nonsystemic antibiotic rifaximin may be a more cost-effective, long-term treatment for hepatic encephalopathy, despite its increased direct cost, because of its demonstrated efficacy and prevention of hospitalization. Further studies evaluating the cost burden of cirrhosis and cirrhosis-related complications, including screening costs, the cost of treatment and maintenance therapy, conveyance to liver transplantation, liver transplantation success, and health-related quality of life after transplantation, are essential for evaluation of the economic burden of hepatic encephalopathy and all cirrhosis-related complications.

The conservative and interventional treatment of the complications of liver cirrhosis: Part 2 of a series on liver cirrhosis

BACKGROUND

It is estimated that 1 million persons in Germany suffer from hepatic cirrhosis, which is the final stage of chronic inflammation of the liver. Cirrhosis has multiple causes, all of which lead to structural changes of the liver and to portal hypertension. The main complications of cirrhosis arise in turn: These include bleeding from collateral veins, ascites, hepatocellular carcinoma, encephalopathy, and infection leading to organ failure.

METHODS

We present the treatment of the main complications of liver cirrhosis with reference to the relevant literature (phase II and III trials, meta-analyses, and reviews).

RESULTS

Endoscopic treatment (ligation) is used for the primary and secondary prophylaxis of variceal bleeding. Drugs to lower portal pressure (e.g., beta-blockers) are an established means of preventing initial or recurrent variceal bleeding over the long term. Vasoconstrictors such as terlipressin are mainly used to treat acute hemorrhage and type 1 hepatorenal syndrome. The main treatment of ascites is with spironolactone, in combination with a loop diuretic where indicated. A shunt (TIPS) is used to treat severe or repeat variceal hemorrhage or refractory ascites. Antibiotics play a well-established role in the treatment of acute hemorrhage, in the treatment and prevention of spontaneous bacterial peritonitis, and in the treatment of encephalopathy. The treatment of hepatocellular carcinoma depends on its extent of spread and on the degree of decompensation of cirrhosis.

CONCLUSION

For most of the main complications of liver cirrhosis, there are treatments that have been well-tested in randomized trials. Liver transplantation should also be considered in every case.

Impact of pretransplant hepatic encephalopathy on liver posttransplantation outcomes

Patients with cirrhosis commonly experience hepatic encephalopathy (HE), a condition associated with alterations in behavior, cognitive function, consciousness, and neuromuscular function of varying severity. HE occurring before liver transplant can have a substantial negative impact on posttransplant outcomes, and preoperative history of HE may be a predictor of posttransplant neurologic complications. Even with resolution of previous episodes of overt or minimal HE, some patients continue to experience cognitive deficits after transplant. Because HE is one of the most frequent pretransplant complications, improving patient HE status before transplant may improve outcomes. Current pharmacologic therapies for HE, whether for the treatment of minimal or overt HE or for prevention of HE relapse, are primarily directed at reducing cerebral exposure to systemic levels of gut-derived toxins (e.g., ammonia). The current mainstays of HE therapy are nonabsorbable disaccharides and antibiotics. The various impacts of adverse effects (such as diarrhea, abdominal distention, and dehydration) on patient's health and nutritional status should be taken into consideration when deciding the most appropriate HE management strategy in patients awaiting liver transplant. This paper reviews the potential consequences of pretransplant HE on posttransplant outcomes and therapeutic strategies for the pretransplant management of HE.

Prevention and treatment of hepatic encephalopathy: Focusing on gut microbiota

The gut flora plays an important role in the pathogenesis of the complications of cirrhosis. Hepatic encephalopathy (HE) represents a broad continuum of neuropsychological dysfunction in patients with acute or chronic liver disease and/or porto-systemic shunting of blood flow and it manifests with progressive deterioration of the superior neurological functions. The pathophysiology of this disease is complex, as it involves overproduction and reduced metabolism of various neurotoxins, particularly ammonia. Management of HE is diversified and requires several steps: elimination of precipitating factors, removal of toxins, proper nutritional support, modulation of resident fecal flora and downregulation of systemic and gut-derived inflammation. This review will provide an overview of gut barrier function and the influence of gut-derived factors on HE, focusing on the role of gut microbiota in the pathogenesis of HE and the recent literature findings on its therapeutic manipulation.

Brain dysfunction primarily related to previous overt hepatic encephalopathy compared with minimal hepatic encephalopathy: resting-state functional MR imaging demonstration

PURPOSE

To investigate whether resting-state brain functional connectivity (FC) differed among cirrhotic patients without overt hepatic encephalopathy (HE) (OHE), those who currently had minimal HE (MHE), or those who had recovered from previous OHE and to investigate whether previous bouts of OHE rather than current MHE predominantly contributed to brain dysfunction in patients without current OHE.

MATERIALS AND METHODS

This study was approved by the institutional ethics committee, and informed consent was obtained. Resting-state functional magnetic resonance (MR) data were compared between healthy controls and the following groups of cirrhotic patients: (a) patients without MHE and without previous OHE, (b) patients with current MHE and without previous OHE, and (c) patients with previous OHE. Independent component analysis was applied to identify the best-fit component for the default-mode network (DMN). One-way analysis of variance was performed to detect different FC among groups. Pearson correlation analyses were conducted to determine the relationships between FC and neurocognitive performance.

RESULTS

Two important regions within the DMN, including the precuneus and posterior cingulate cortex and left medial frontal gyrus, showed significantly different FC among the four groups. A trend of gradually reduced FC in two regions was observed from controls, to patients without HE, and to patients with current MHE, while patients with previous OHE showed remarkably reduced FC in these two regions. Significant correlations were found between FC and neurocognitive performance in cirrhotic patients.

CONCLUSION

The reduced resting-state FC within DMN was associated with neurocognitive impairments in MHE and after clinical resolution of OHE. Previous OHE rather than current MHE might be primarily related to brain dysfunction in patients with latent OHE.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120026/-/DC1.

Rifaximin therapy and hepatic encephalopathy: Pros and cons

Hepatic encephalopathy (HE) is the second most common major complication in cirrhotics and it significantly impacts quality of life. Therapeutic approaches for HE treatment and prevention mainly continue to rely on ammonia-lowering strategies and non-absorbable disaccharides are currently considered the cornerstone therapy. Non-absorbable antibiotics, such as neomycin and paramomycin, are effective in treatment of acute HE episodes but their prolonged use for recurrence prevention is hampered by possible side-effects. To overcome these limitations, rifaximin use has been proposed. Rifaximin has been shown to be not superior to non-absorbable disaccharides for either HE treatment or prevention, with a similar incidence of side-effects. Cirrhosis significantly increases rifaximin absorption and this could be a cause for concern. Following long-term rifaximin therapy, Clostridium difficile colitis has been observed and Candida albicans has been isolated from 20% of patients. In addition, selection of resistant mutants of both Gram-negative and -positive bacteria in the gastrointestinal tract cannot be definitely ruled out. Electrolyte alterations (sodium and potassium) have been reported during rifaximin therapy, a warning for its long-term use in cirrhotics. Moreover, a potential interference with vitamin K production should be considered which could further impair the already altered clotting status of these patients. The therapeutic cost of rifaximin is markedly higher than non-absorbable disaccharides. While waiting for further safety data, caution should be used to limit the use of rifaximin therapy for a very short-term period in selected HE cirrhotics not responding to non-absorbable disaccharides.

Primary prophylaxis of overt hepatic encephalopathy in patients with cirrhosis: an open labeled randomized controlled trial of lactulose versus no lactulose

BACKGROUND AND AIM

Development of overt hepatic encephalopathy (HE) is associated with poor prognosis in patients with cirrhosis. Lactulose is used for the treatment of HE. There is no study on the prevention of overt HE using lactulose in patients who never had HE earlier.

METHODS

Consecutive cirrhotic patients who never had an episode of overt HE were randomized to receive lactulose (Gp-L) or no lactulose (Gp-NL). All patients were assessed by psychometry (number connection test [NCT-A and B], figure connection test if illiterate [FCT-A and B], digit symbol test [DST], serial dot test [SDT], line tracing test [LTT]) and critical flicker frequency test (CFF) at inclusion and after 3 months. These patients were followed every month for 12 months for development of overt HE.

RESULTS

Of 250 patients screened, 120 (48%) meeting the inclusion criteria were randomized to Gp-L (n = 60) and Gp-NL (n = 60). Twenty (19%) of 105 patients followed for 12 months developed an episode of overt HE. Six (11%) of 55 in the lactulose (Gp-L) group and 14 (28%) of 50 in the Gp-NL (P = 0.02) developed overt HE. Ten (20%) of 50 patients in Gp-NL and five (9%) of 55 patients in the Gp-L group died, P = 0.16. Number of patients with minimal hepatic encephalopathy (MHE) were comparable in two groups at baseline (Gp-L vs Gp-NL, 32:36, P = 0.29). Lactulose improved MHE in 66% of patients in Gp-L. Taking a cutoff < 38 Hz sensitivity and specificity of CFF in predicting HE were 52% and 77% at baseline and 52% and 82% at 3 months of treatment. On multivariate analysis, Child's score and presence of MHE at baseline were significantly associated with development of overt HE.

CONCLUSIONS

Lactulose is effective for primary prevention of overt hepatic encephalopathy in patients with cirrhosis.

Secondary prophylaxis of hepatic encephalopathy in cirrhosis: an open-label, randomized controlled trial of lactulose, probiotics, and no therapy

OBJECTIVES

Lactulose is effective in secondary prophylaxis of hepatic encephalopathy (HE). Probiotics improves minimal hepatic encephalopathy (MHE), which predisposes to HE. No study has been conducted on the secondary prophylaxis of HE using probiotics. Our objective was to study the effects of lactulose and probiotics for secondary prophylaxis of HE.

METHODS

Consecutive cirrhotic patients who had recovered from HE were randomized to receive lactulose (Gp-L, 30 ml three times per day), three capsules of probiotics (Gp-P) per day containing 112.5 billion viable lyophilized bacteria per capsule, or no therapy (Gp-N). All patients were assessed by psychometry (number connection test (NCT-A, B), figure connection test if illiterate (FCT-A, B), digit symbol test (DST), and block design test (BDT)), critical flicker frequency (CFF) test, and arterial ammonia at inclusion. The patients were followed up monthly. The primary end point was development of overt HE according to West Haven criteria or a follow-up of 12 months.

RESULTS

Of 360 patients who recovered, 235 (65.2%) met the inclusion criteria (Gp-L, n=80; Gp-P, n=77; and Gp-N, n=78). In all, 38 patients (16.1%) were lost to follow-up and 77 patients developed HE (Gp-L, n=18; Gp-P, n=22; and Gp-N, n=37). There was a significant difference between Gp-L and Gp-N (P=0.001) and between Gp-P and Gp-N (P=0.02) but no difference between the Gp-L and Gp-P groups (P=0.349). The rate of readmission for causes other than HE (Gp-L, Gp-P, and Gp-N, 19:21:28; P=0.134) and deaths (Gp-L:Gp-P:Gp-N=13:11:16; P=0.56) in all three groups were similar. There was a high prevalence of abnormal psychometry test results (NCT-A, 71.5%; NCT-B, 69.2%; DST, 76.9%; and BDT, 85.2%), and FCT-A and -B were abnormal in 35 of 48 patients (72.7%). CFF was <38 Hz in 118 patients (50.2%). Upon multivariate analysis, recurrence of overt HE was significantly associated with two or more abnormal psychometric tests and arterial ammonia after the recovery of an episode of HE.

CONCLUSIONS

Lactulose and probiotics are effective for secondary prophylaxis of HE in patients with cirrhosis.

A longitudinal systems biology analysis of lactulose withdrawal in hepatic encephalopathy

The pathogenesis of hepatic encephalopathy(HE) is unclear. However gut flora changes, inflammation and neuro-glial injury have been implicated. The aim was to evaluate factors that were associated with HE recurrence after lactulose withdrawal by analyzing the clinical phenotype, stool microbiome and systemic metabolome longitudinally. HE patients on a standard diet who were adherent on lactulose underwent characterization of their phenotype [cognition, inflammatory cytokines, in-vivo brain MR spectroscopy(MRS)], gut microbiome (stool Multitag Pyrosequencing) and metabolome (urine/serum ex-vivo MRS) analysis while on lactulose and on days 2, 14 and 30 post-withdrawal. Patients whose HE recurred post-withdrawal were compared to those without recurrence. We included seven men (53 ± 8 years) who were adherent on lactulose after a precipitated HE episode were included. HE recurred in three men 32 ± 6 days post-withdrawal. In-vivo brain MRS showed increased glutamine+glutamate (Glx) and decreased myoinositol with a reduction in stool Faecalibacterium spp., post-withdrawal. HE recurrence was predicted by poor baseline inhibitory control and block design performance and was associated with a shift of choline metabolism from tri-methylamine oxide formation towards the development of di-methylglycine, glycine and creatinine. This was accompanied by a mixed effect on the immune response (suppressed IL-10 and Th1/Th2/Th17 response). The correlation network showed Prevotella to be linked to improved cognition and decreased inflammation in patients without HE recurrence. We conclude that lactulose withdrawal results in worsening cognition, mixed inflammatory response effect, lowered stool Faecalibacterium and increase in MR-measurable brain Glx. HE recurrence post-lactulose withdrawal can be predicted by baseline cognitive performance and is accompanied by disrupted choline metabolism.

Hepatic encephalopathy

Hepatic encephalopathy (HE) represents a continuum of transient and reversible neurologic and psychiatric dysfunction. It is a reversible state of impaired cognitive function or altered consciousness in patients with liver disease or portosystemic shunting. Over the last several years, high-quality studies have been conducted on various pharmacologic therapies for HE; as more data emerge, it is hoped that HE will become a more easily treated complication of decompensated liver disease. In the interim, it is important that physicians continue to screen for minimal HE and treat patients early in addition to continuing to provide current treatments of overt HE.

The diagnosis and treatment of minimal hepatic encephalopathy

BACKGROUND

The subtype of hepatic encephalopathy (HE) called minimal hepatic encephalopathy (MHE) is highly prevalent (22-74%) among patients with liver dysfunction. MEH is defined as HE without grossly evident neurologic abnormalities, but with cognitive deficits that can be revealed by psychometric testing.

METHODS

This article is based on relevant original publications and reviews in English and German (1970-2011) that were retrieved by a selective key-word-based search in the Medline and PubMed databases.

RESULTS

Despite its mild manifestations, MHE impairs patients' quality of life and their ability to work. It impairs driving ability and is associated with a higher rate of motor vehicle accidents. Furthermore, patients with MHE fall more often and are more likely to undergo progression to overt HE. The main pathophysiological mechanism of MHE is hyperammonemia leading to astrocyte dysfunction. Psychometric tests are the standard instruments for establishing the diagnosis; further, supportive diagnostic tools include neurophysiological tests and imaging studies. Recent randomized and controlled trials have revealed that treatment with lactulose or rifaximin therapy improves the quality of life of patients with MHE. Rifaximin was also found to improve driving performance in a simulator. A combination of these two drugs prevents the recurrence of episodic HE over a 6-months follow-up period. Moreover, small-scale trials have revealed that some dietary supplements can improve the cognitive deficits of MHE.

CONCLUSION

Clinical trials have shown that patients with MHE and patients who have had an episode of overt HE in the past can benefit from drug treatment.

Management of overt hepatic encephalopathy

Hepatic encephalopathy (HE) is a potentially reversible state of impaired cognitive function or altered consciousness in patients with liver disease or portosystemic shunting. Overt HE is a particularly pressing problem. Given the many targets of treatment and lack of a clear singular cause of overt HE, there is no consensus on a single best treatment. Over the past several years, high-quality studies have been conducted on the various pharmacologic therapies for HE and, as more data emerge, hopefully HE will become a much more easily treated complication of decompensated liver disease.

A current review of the diagnostic and treatment strategies of hepatic encephalopathy

Hepatic encephalopathy (HE) is a serious and potentially fatal complication in patients with cirrhotic liver disease. It is a spectrum ranging from minimal hepatic encephalopathy (MHE) without recognizable clinical symptoms or signs, to overt HE with risk of cerebral edema and death. HE results in diminished quality of life and survival. The broad range of neuropsychiatric manifestations reflects the range of pathophysiological mechanisms and impairment in neurotransmission that are purported to cause HE including hyperammonemia, astrocyte swelling, intra-astrocytic glutamine, upregulation of 18-kDa translocator protein (TSPO) (formerly known as peripheral benzodiazepine receptor or PBTR), and manganese. There is a myriad of diagnostic tools including simple bedside clinical assessment, and more complex neuropsychological batteries and neurophysiological tests available today. Current treatment strategies are directed at reducing ammonia, with newer agents showing some early promise. This paper describes the pathophysiology of the disease and summarises current diagnostic and treatment therapies available.

Functional analysis of colonic bacterial metabolism: relevant to health?

With the use of molecular techniques, numerous studies have evaluated the composition of the intestinal microbiota in health and disease. However, it is of major interest to supplement this with a functional analysis of the microbiota. In this review, the different approaches that have been used to characterize microbial metabolites, yielding information on the functional end products of microbial metabolism, have been summarized. To analyze colonic microbial metabolites, the most conventional way is by application of a hypothesis-driven targeted approach, through quantification of selected metabolites from carbohydrate (e.g., short-chain fatty acids) and protein fermentation (e.g., p-cresol, phenol, ammonia, or H(2)S), secondary bile acids, or colonic enzymes. The application of stable isotope-labeled substrates can provide an elegant solution to study these metabolic pathways in vivo. On the other hand, a top-down approach can be followed by applying metabolite fingerprinting techniques based on (1)H-NMR or mass spectrometric analysis. Quantification of known metabolites and characterization of metabolite patterns in urine, breath, plasma, and fecal samples can reveal new pathways and give insight into physiological regulatory processes of the colonic microbiota. In addition, specific metabolic profiles can function as a diagnostic tool for the identification of several gastrointestinal diseases, such as ulcerative colitis and Crohn's disease. Nevertheless, future research will have to evaluate the relevance of associations between metabolites and different disease states.

Pathogenesis and management of alcoholic liver cirrhosis: a review

Little is known about how alcohol causes liver disease and cirrhosis. The strongest evidence of the causality between alcohol and liver disease stems from epidemiological observations. Factors contributing to alcohol-induced fibrosis and cirrhosis include cytokines, oxidative stress, and toxic metabolites of ethanol. Patients with alcoholic cirrhosis generally have complications at diagnosis, and cirrhotic complications should be actively assessed because they are closely associated with subsequent morbidity as well as mortality. Abstinence is strictly required to prevent disease progression and is critical for eventual liver transplantation. In addition, nutritional therapy remains the mainstay of managing alcoholic cirrhosis.

Critical care management of patients with end-stage liver disease

OBJECTIVES

To review the management of complications related to end-stage liver disease in the intensive care unit. The goal of this review is to address topics important to the practicing physician.

DATA SOURCES

We performed an organ system-based PubMed literature review focusing on the diagnosis and treatment of critical complications of end-stage liver disease. DATA SYNTHESIS AND FINDINGS: When available, preferential consideration was given to randomized controlled trials. In the absence of trials, observational and retrospective studies and consensus opinions were included. We present our recommendations for the neurologic, cardiovascular, pulmonary, gastrointestinal, renal, and infectious complications of end-stage liver disease.

CONCLUSIONS

Complications related to end-stage liver disease have significant morbidity and mortality. Management of these complications in the intensive care unit requires awareness and expertise among physicians from a wide variety of fields.

Lactulose: production, purification and potential applications

Lactulose a "bifidus factor" is composed of galactose and fructose, which can be produced by the isomerization of lactose. It is a prebiotic carbohydrate which stimulates the growth of health-promoting bacteria in the gastrointestinal tract, such as bifidobacteria and lactobacilli and at the same time inhibits growth of pathogenic bacteria such as Salmonella. It can also be used for the treatment of constipation, hepatic encephalopathy, tumour prevention, and to maintain blood glucose and insulin level. This review provides comprehensive information on the different techniques used for the production of lactulose, purification and analysis. Besides this mechanism of action and its potential applications in food and pharmaceutical industries have also been discussed.

Rifaximin: new therapeutic indication and future directions

BACKGROUND

Rifaximin is a nonabsorbable oral antibiotic that acts locally in the gastrointestinal tract with minimal systemic adverse effects. Rifaximin received new labeling for reduction in the risk of the recurrence of overt hepatic encephalopathy (HE) in patients with advanced liver disease in March of 2010.

OBJECTIVE

This article reviews the pharmacology, pharmacokinetics, and pharmacodynamics of rifaximin. The efficacy and safety of rifaximin in reducing the risk of the recurrence of overt HE in patients with advanced liver disease, the new US Food and Drug Administration-approved indication, is the focus of this review. Emerging data on the use of rifaximin in irritable bowel syndrome (IBS) and Clostridium difficile infection (CDI) are also evaluated.

METHODS

MEDLINE and International Pharmaceutical Abstracts from 1983 to January 31, 2011, were searched using the key terms rifaximin, L/105, secondary hepatic encephalopathy, irritable bowel syndrome, and Clostridium difficile. Ongoing trials were identified using the clinicaltrials.gov Web site. Abstracts from the annual meetings of the American College of Gastroenterology and Digestive Disease Week from 2004 to 2010 and references from relevant articles were reviewed. Only trials examining use of rifaximin in secondary prophylaxis of HE were included. Studies on the efficacy and safety of rifaximin in the treatment of acute episodes of HE have been recently summarized elsewhere and are not reviewed here.

RESULTS

Literature search identified one trial on rifaximin use in secondary prevention of HE, six trials in patients with IBS, and six small studies and case reports in patients with CDI. In a trial of 299 patients, use of rifaximin 550 mg by mouth twice daily for 6 months for prevention of recurrent HE was associated with significantly fewer breakthrough HE episodes compared with placebo (rifaximin 22%, placebo 46%; P < 0.001), with a hazard ratio of 0.42 (95% CI, 0.28-0.64). The rifaximin group also had fewer hospitalizations involving HE compared with placebo (rifaximin 13.6%, placebo 22.6%; P = 0.01), with a hazard ratio of 0.50 (95% CI, 0.29-0.87). Rifaximin improved IBS symptom management in ∼9% more patients than placebo in 2 prospective, randomized, double-blind, placebo-controlled trials of 1260 patients (in the rifaximin group, 40.8% patients reported IBS symptom improvement compared with 31.7% in the placebo group; P < 0.001). The efficacy of rifaximin has been reported for the treatment of refractory or recurrent CDI in small studies, case series, and a case report. Optimal dosing, duration, and role of rifaximin for CDI management is unclear. In clinical trials of rifaximin for prevention of recurrent HE and for nonconstipated IBS, its safety profile was comparable to placebo. In the trial of rifaximin for prevention of recurrent HE, the most common adverse events occurring in 10% to 15% of patients were ascites, dizziness, fatigue, and peripheral edema. Most common adverse effects in IBS trials included abdominal pain, diarrhea, bad taste, headache, and upper respiratory tract infection, occurring in <10% of patients.

CONCLUSIONS

Rifaximin can be an effective option for reduction in the risk of the recurrence of HE in patients with advanced liver disease. Studies suggest that rifaximin provides relief of global symptoms of diarrhea-predominant IBS and bloating. Use of rifaximin in CDI requires further study.

Prophylaxis of hepatic encephalopathy in acute variceal bleed: a randomized controlled trial of lactulose versus no lactulose

BACKGROUND AND AIMS

Acute variceal bleed (AVB) is an important precipitating factor for development of hepatic encephalopathy (HE). However, there is paucity of data on the role of lactulose for prevention of HE after AVB. We evaluated the role of lactulose for prophylaxis of HE after AVB.

METHODS

Consecutive patients of cirrhosis with AVB enrolled. Patients included if >18 years old and had no HE at the time of presentation. Patients were randomized to receive lactulose (Group-L) or no lactulose (Group-P) along with standard treatment of AVB as per Baveno 4 guidelines. Primary endpoint was development of overt HE as per West Haven criteria within 120 h of randomization.

RESULTS

Seventy patients were randomized into group-L (Gp-L, n = 35) and group-P (Gp-P, n = 35). There was no significant difference in baseline characteristics between the two groups. Characteristics of variceal bleed were also similar (Gp-L vs Gp-P [mean arterial pressure 81.0 ± 10.5 vs 79.5 ± 9.9 mmHg], Hb [8.4 ± 1.5 vs 9.3 ± 2.3 g/dL], blood transfusion requirement [1.6 ± 1.1 vs 1.3 ± 0.9 units], time to endoscopy [6.3 ± 2.8 vs 7.0 ± 3.1 h], and esophageal source of bleed [92% vs 88%]). Nineteen (27%) patients developed HE; five patients (14%) in Gp-L and 14 patients (40%) in Gp-P, P = 0.03. The median grade of HE was 2 (range 2-4) and median time interval of development of HE after randomization was 2 days (range 1-4). Nine patients (13%) died; three (8.5%) patients in Gp-L and six (17%) patients in Gp-P, P = 0.23. Patients who developed HE had significantly higher baseline Child-Turcotte-Pugh score score (10.2 ± 1.2 vs 9.4 ± 1.4 P = 0.04), model for end stage liver disease score (18.2 ± 3.9 vs 15.4 ± 4.5 P = 0.02), arterial ammonia level (112.2 ± 22.7 vs 94.8 ± 17.6 umol/L, P = 0.001), baseline total leukocyte count (10,505.2 ± 8911.9 vs 5784.3 ± 3387.0 P = 0.002), total bilirubin (3.4 ± 1.3 vs 2.1 ± 1.8 mg%, P = 0.008) as compared to patients who did not develop HE. On multivariate analysis only baseline arterial ammonia, blood requirement during hospital stay and lactulose therapy were predictors of development of HE.

CONCLUSIONS

Lactulose is effective in prevention of HE in patients with cirrhosis and acute variceal bleed.

Complications and outcomes in chronic liver disease

PURPOSE OF REVIEW

Chronic liver disease (CLD) causes significant morbidity and mortality, mainly due to complications [hepatic encephalopathy, ascites, hepatorenal syndrome (HRS) and esophageal variceal hemorrhage (EVH)]. Studies of the complications, management and outcomes in patients with CLD over the last 18 months are reviewed.

RECENT FINDINGS

Predictors of response to lactulose therapy in hepatic encephalopathy have been reported, along with the effect of minimal hepatic encephalopathy on driving. Rifaximin was found to lead to better maintenance of remission and decreased readmission rates in patients with cirrhosis and hepatic encephalopathy. Satavaptan (a vasopressin receptor antagonist) was investigated for treatment of refractory ascites and appeared to be effective, but this compound is not currently approved by the US Food and Drug Administration (FDA). Patients with refractory ascites taking propranolol were found to have poorer outcomes than those not taking propranolol. Terlipressin currently appears to be the best medical therapy available for patients with type 1 HRS; the addition with albumin to terlipressin appeared to decrease mortality in patients with type 1 HRS. In primary prophylaxis of EVH, carvedilol was found to reduce the rate of initial bleeding compared with band ligation. Early transjugular intrahepatic portosystemic shunts placed in highly selected patients with acute EVH and a high risk of endoscopic failure decreased long-term mortality. In patients with gastric varices, primary prophylaxis with cyanoacrylate may decrease the probability of gastric variceal hemorrhage compared with nonselective beta-blockers.

SUMMARY

Refinement in clinical management strategies for patients with cirrhosis and its complications appear to continue to contribute to improved patient outcomes.

Review article: the design of clinical trials in hepatic encephalopathy--an International Society for Hepatic Encephalopathy and Nitrogen Metabolism (ISHEN) consensus statement

BACKGROUND

The clinical classification of hepatic encephalopathy is largely subjective, which has led to difficulties in designing trials in this field.

AIMS

To review the current classification of hepatic encephalopathy and to develop consensus guidelines on the design and conduct of future clinical trials.

METHODS

A round table was convened at the 14th International Society for Hepatic Encephalopathy and Nitrogen Metabolism (ISHEN) meeting. Key discussion points were the nomenclature of hepatic encephalopathy and the selection of patients, standards of care and end-points for assessing the treatment and secondary prevention of hepatic encephalopathy.

RESULTS

It was generally agreed that severity assessment of hepatic encephalopathy in patients with cirrhosis, whether made clinically or more objectively, should be continuous rather than categorical, and a system for assessing the SONIC (Spectrum of Neuro-cognitive Impairment in Cirrhosis) was proposed. Within this system, patients currently classified as having minimal hepatic encephalopathy and Grade I hepatic encephalopathy would be classified as having Covert hepatic encephalopathy, whereas those with apparent clinical abnormalities would continue to be classified as overt hepatic encephalopathy. Some aspects of the terminology require further debate. Consensus was also reached on the patient populations, standards of care and endpoints to assess clinical trial outcomes. However, some compromises had to be made as there is considerable inter- and intravariability in the availability of some of the more objective surrogate performance markers.

CONCLUSIONS

The objectives of the round table were met. Robust, defendable guidelines for the conduct of future studies into hepatic encephalopathy have been provided. Outstanding issues are few and will continue to be discussed.

Meta-analysis: the effects of gut flora modulation using prebiotics, probiotics and synbiotics on minimal hepatic encephalopathy

BACKGROUND

Minimal hepatic encephalopathy (MHE) is characterised by subtle neurocognitive deficits without overt clinical manifestations. Although several trials have individually evaluated the role of prebiotics, probiotics and synbiotics, there is yet no consensus on the management of MHE.

AIM

To estimate the efficacy of prebiotics, probiotics and synbiotics in MHE in randomised controlled trials.

METHODS

MEDLINE, EMBASE, CINAHL and the Cochrane Database of Systematic Reviews were searched for published studies in all languages. Inclusion and exclusion criteria were defined a priori. Pooled relative risk and heterogeneity were estimated as the measures of association.

RESULTS

Nine studies met our inclusion criteria. Use of prebiotics, probiotics and synbiotics significantly reduced the pooled relative risk (RR) of no improvement of MHE (RR 0.40, 95% CI 0.32-0.50; P<0.001). Upon subgroup analysis, five studies with lactulose showed significant reduction of risk of no improvement of MHE (RR 0.34, 95% CI 0.24-0.47; P<0.0001) with no inter-trial heterogeneity. In two trials each of probiotics and synbiotics, their use was associated with significant beneficial effects (RR 0.41, 95% CI 0.26-0.65; P<0.0001 and RR of 0.51, 95% CI 0.32-0.80; P=0.004 respectively). There were no major adverse events though probiotics and synbiotics were better tolerated than lactulose.

CONCLUSIONS

The use of prebiotics, probiotics and synbiotics was associated with significant improvement in minimal hepatic encephalopathy. Among individual agents, lactulose appears to have the most beneficial effect, followed closely by probiotics and synbiotics.

Minimal hepatic encephalopathy is associated with falls

OBJECTIVES

Minimal hepatic encephalopathy (MHE) reduces quality of life and impacts daily functioning. It is known to impair fitness to drive, but deficits in attention and reaction may also be associated with falls. Falls may have important consequences in patients with cirrhosis due to coagulopathy, osteoporosis, and operative risk. However, the relationship between MHE and falls has not yet been evaluated. The objective of this study is to retrospectively investigate whether MHE is associated with falls in patients with cirrhosis.

METHODS

We included 130 cirrhotic outpatients and 43 controls. MHE was diagnosed according to the results of the psychometric hepatic encephalopathy score (PHES). We recorded the reported incidence and number of falls in the 12 months before the study, the severity of injuries, and the need for healthcare services.

RESULTS

Forty-five (34.6%) patients with cirrhosis exhibited MHE. The proportion of patients with MHE that reported falls (40%) was higher than those without MHE (12.9%, P<0.001), which was similar to controls (11.6%). In patients with MHE, there was a higher need for primary healthcare services (8.8 vs. 0%, P=0.004) and hospitalization (6.6 vs. 2.3%, P=0.34) due to falls than in patients without MHE. Patients on psychoactive drugs (n=21) showed a stronger association between MHE and falls: 6/8 (75%) patients with MHE presented falls vs. 2/13 (15.3%) patients without MHE (P=0.01). In patients not receiving psychoactive drugs (n=109), the incidence of falls was 12/37 (32.4%) in patients with MHE vs. 9/72 (12.5%) in those without MHE (P=0.01). Multivariate analysis showed that MHE (odds ratio (OR): 2.91, 95% confidence interval (CI): 1.13-7.48, P=0.02), previous encephalopathy (OR: 2.87, 95% CI: 1.10-7.50, P=0.03), and antidepressant therapy (OR: 3.91, 95% CI: 0.96-15.9, P=0.05) were independent factors associated to previous falls.

CONCLUSIONS

Falls are more frequent in cirrhotic patients with MHE, particularly in those on treatment with psychoactive drugs, and are a significant cause for healthcare and hospitalization requirements.

Hepatobiliäre Funktionsstörungen und Leberversagen

Als »sepsisinduzierte Cholestase« bezeichnet man das Auftreten einer konjugierten Hyperbilirubinämie als Folge einer extrahepatischen bakteriellen Infektion ohne direkte Invasion der Leber durch Erreger.

Rifaximin for the treatment of hepatic encephalopathy

Hepatic encephalopathy (HE) is a complication of cirrhosis, the severity of which can range from subtle, neurocognitive dysfunction (minimal HE) to more apparent and severe cognitive and motor manifestations with increasing grades of the condition (overt HE). Current treatment options are targeted at reducing the levels of ammonia and other gut-derived toxins, the purported culprits behind the pathogenesis of HE. One of these therapeutic options, the nonsystemic antibiotic rifaximin, is efficacious for the treatment of minimal and overt HE. However, HE may be a cyclic condition in which patients with overt HE enter remission following treatment and then relapse. Thus, safe, effective and well-tolerated treatments are needed to maintain HE remission. Rifaximin maintained HE remission more effectively than placebo in a large, randomized controlled trial. Rifaximin is safe and well-tolerated for the treatment of minimal and overt HE and for the maintenance of HE remission.

Prevalence of abnormal psychometric tests and critical flicker frequency after clinical recovery of overt hepatic encephalopathy

BACKGROUND

Abnormal psychometric tests are common in cirrhotic patients without overt encephalopathy. It may seriously impair the patient's daily functioning and quality of life. Prevalence of abnormal psychometric tests after the clinical recovery of overt encephalopathy has not been studied.

MATERIALS AND METHODS

Consecutive 80 patients (age, 44.5+/-9.8 yr; M: F 66:14) with hepatic encephalopathy (HE) who recovered and met inclusion criteria were evaluated for abnormal psychometric tests ( > 2 SD) and critical flicker frequency (CFF < 38 Hz). All patients underwent number connection tests-A and B, figure connection tests -A and B (if illiterate), digit symbol test, object assembly test, CFF and arterial ammonia after one month of clinical recovery of HE.

RESULTS

Prevalence of abnormal psychometric tests (> 2SD) was seen in 58 (72.5%) patients. [33 (66%) of 50 patients on lactulose and 25 (83%) of 30 patients not on lactulose, P = 0.12]. Arterial ammonia was significantly higher in patients with abnormal psychometric tests compared to patients without it (86.3+/-22.2 vs 50.4+/-11.5 mmol/l, P = 0.01). CFF was < 38 Hz in 50 patients (62.5%). Patients with > or =2 abnormal psychometric tests had CFF significantly lower than with normal psychometric tests (35.6+/-2.3 vs 40.7+/-2.4 Hz, P = 0.001). CFF sensitivity and specificity in diagnosing > or =2 abnormal psychometric tests was 82 and 83% respectively. CFF was significantly correlated with psychometric tests [NCT-A (-0.672, P = 0.001) and B (-0.743, P = 0.001), digit symbol test (-0.533, P = 0.001), object assembly test (-0.659, P =0.001) and arterial ammonia level (-0.385, P = 0.02)].

CONCLUSION

About 73% of patients who recovered from HE had abnormal psychometric tests ( > 2SD). CFF is a simple reliable tool to find out the presence of abnormal tests.

Pharmacotherapy of hepatic encephalopathy in cirrhosis

IMPORTANCE OF THE FIELD

Hepatic encephalopathy (HE) is a major complication encountered in nearly half of the patients with liver cirrhosis.

AREAS COVERED IN THIS REVIEW

A review of the safety and efficacy of current therapies for HE that seek to pre-empt ammonia production and/or to increase its elimination, reducing inflammation, blocking benzodiazepine-like compound production, and supporting systemic hemodynamics.

WHAT THE READER WILL GAIN

Insight into some recent advances in the management of HE that could modify our therapeutic approach to end-stage liver disease. Cirrhotic individuals during an overt HE episode require careful management, focusing on precipitant factors as well as metabolic and hemodynamic derangements.

TAKE HOME MESSAGE

Intestinal ammoniagenesis requires flora modification by antibiotics, prebiotics and probiotics; glutaminase inhibition as well as antibiotics to pre-empt systemic inflammation. Hemodynamic/fluid support is essential. Nutritional support is crucial and hypoproteinemic diets should be avoided. Blocking benzodiazepine-like compounds by the use of flumazenil could be useful in patients with severe, benzodiazepine-induced HE. Long-term rifaximin is well tolerated, does not promote resistance and could decrease overt HE bouts in patients with previous episodes of overt HE. Lactulose is better than no treatment in improving quality of life in patients with minimal HE; it also acts as secondary prophylaxis following overt HE.

Changing face of hepatic encephalopathy: Role of inflammation and oxidative stress

The face of hepatic encephalopathy (HE) is changing. This review explores how this neurocognitive disorder, which is associated with both acute and chronic liver injury, has grown to become a dynamic syndrome that spans a spectrum of neuropsychological impairment, from normal performance to coma. The central role of ammonia in the pathogenesis of HE remains incontrovertible. However, over the past 10 years, the HE community has begun to characterise the key roles of inflammation, infection, and oxidative/nitrosative stress in modulating the pathophysiological effects of ammonia on the astrocyte. This review explores the current thoughts and evidence base in this area and discusses the potential role of existing and novel therapies that might abrogate the oxidative and nitrosative stresses inflicted on the brain in patients with, or at risk of developing, HE.

Minimal hepatic encephalopathy: consensus statement of a working party of the Indian National Association for Study of the Liver

Hepatic encephalopathy (HE) is a major complication that develops in some form and at some stage in a majority of patients with liver cirrhosis. Overt HE occurs in approximately 30-45% of cirrhotic patients. Minimal HE (MHE), the mildest form of HE, is characterized by subtle motor and cognitive deficits and impairs health-related quality of life. The Indian National Association for Study of the Liver (INASL) set up a Working Party on MHE in 2008 with a mandate to develop consensus guidelines on various aspects of MHE relevant to clinical practice. Questions related to the definition of MHE, its prevalence, diagnosis, clinical characteristics, pathogenesis, natural history and treatment were addressed by the members of the Working Party.

Hepatic encephalopathy therapy: An overview

Type-C hepatic encephalopathy (HE) is a severe complication of cirrhosis, which seriously affects quality of life and is strongly related to patient survival. Treatment based on a classical pharmacological approach that is aimed at reducing the production of gut-derived toxins, such as ammonia, is still under debate. Currently, results obtained from clinical trials do not support any specific treatment for HE and our competence in testing old and new treatment modalities by randomized controlled trials with appropriate clinically relevant end-points urgently needs to be improved. On the other hand, patients who are at risk for HE are now identifiable, based on studies on the natural history of the disease. Today, very few studies that are specifically aimed at establishing whether HE may be prevented are available or in progress. Recent studies have looked at non absorbable disaccharides or antibiotics and other treatment modalities, such as the modulation of intestinal flora. In the treatment of severe stage HE, artificial liver supports have been tested with initial positive results but more studies are needed.

A double-blind, randomized, placebo-controlled trial of intravenous L-ornithine-L-aspartate on postural control in patients with cirrhosis

INTRODUCTION

Hepatic encephalopathy (HE) is a complication of liver disease. Several treatments have been introduced but only L-ornithine-L-aspartate (LOLA) shows proven efficacy. This double-blind, randomized, placebo-controlled trial evaluated the effect of LOLA on postural control in cirrhotics.

METHODS

Forty patients were randomized to either LOLA or a placebo. HE was evaluated by psychometric testing (PSE Syndrome Test) and critical flicker frequency (CFF). Posturography [equilibrium score (ES)] provided information regarding postural control. Peripheral blood was analysed for ammonia concentration (NH(3)) and the partial pressure of ammonia (pNH(3)).

RESULTS

Both groups were comparable regarding baseline variables. Posturography and PSE Syndrome Test improved in both groups; improvement was greater in the LOLA group (ES: 5.3%; PSE: 1.9) compared with the placebo (ES: 3.9%; PSE: 1.3) but did not reach significance (ES: P=0.3; PSE: P=0.5). CFF remained unchanged during treatment and between groups (P=NS). NH(3) decreased in the LOLA group (Delta: -15 micromol/L) and slightly increased in the placebo group (Delta: 11.1 micromol/L), but the differences did not reach statistical significance (P=0.07). pNH(3) remained largely unchanged (LOLA Delta: -1.2 x 10(-5) mmHg vs. placebo Delta: -0.3 x 10(-5) mmHg; P=0.21).

CONCLUSION

In the LOLA group, an improvement of posturographic control and PSE Syndrome Test was observed, but a similar improvement was also achieved by the placebo. In LOLA, ammonia levels tended to decrease while they tended to increase in the placebo group. LOLA might augment the improvement achieved by intravenous fluids alone but a larger cohort will be needed to show this effect with statistical significance.

Rifaximin treatment in hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a chronically debilitating complication of hepatic cirrhosis. The efficacy of rifaximin, a minimally absorbed antibiotic, is well documented in the treatment of acute hepatic encephalopathy, but its efficacy for prevention of the disease has not been established.

METHODS

In this randomized, double-blind, placebo-controlled trial, we randomly assigned 299 patients who were in remission from recurrent hepatic encephalopathy resulting from chronic liver disease to receive either rifaximin, at a dose of 550 mg twice daily (140 patients), or placebo (159 patients) for 6 months. The primary efficacy end point was the time to the first breakthrough episode of hepatic encephalopathy. The key secondary end point was the time to the first hospitalization involving hepatic encephalopathy.

RESULTS

Rifaximin significantly reduced the risk of an episode of hepatic encephalopathy, as compared with placebo, over a 6-month period (hazard ratio with rifaximin, 0.42; 95% confidence interval [CI], 0.28 to 0.64; P<0.001). A breakthrough episode of hepatic encephalopathy occurred in 22.1% of patients in the rifaximin group, as compared with 45.9% of patients in the placebo group. A total of 13.6% of the patients in the rifaximin group had a hospitalization involving hepatic encephalopathy, as compared with 22.6% of patients in the placebo group, for a hazard ratio of 0.50 (95% CI, 0.29 to 0.87; P=0.01). More than 90% of patients received concomitant lactulose therapy. The incidence of adverse events reported during the study was similar in the two groups, as was the incidence of serious adverse events.

CONCLUSIONS

Over a 6-month period, treatment with rifaximin maintained remission from hepatic encephalopathy more effectively than did placebo. Rifaximin treatment also significantly reduced the risk of hospitalization involving hepatic encephalopathy. (ClinicalTrials.gov number, NCT00298038.)

Hyponatremic and hepatic encephalopathies: similarities, differences and coexistence

Hyponatremic and hepatic encephalopathy are common causes of metabolic encephalopathy that may coexist in patients with cirrhosis. The clinical picture is common to any metabolic encephalopathy and is characterized by a confusional syndrome that may evolve into coma. Chronic mild or minimal manifestations can be seen in both, but motor symptoms are more common in hepatic encephalopathy. Recent advances show that in addition to clinical manifestations both encephalopathies share some pathogenetic mechanisms. Dysfunction of astrocytes, osmotic changes in the brain and brain edema are present in both situations. Recognition of these abnormalities is important to plan therapy. New drugs that affect brain hydration may be useful for both encephalopathies.