LDL-cholesterol: The lower the better. / Colesterol LDL, cuanto más bajo mejor.

The reduction of low density lipoprotein-cholesterol (LDL-chol) has been associated with a decrease in cardiovascular morbidity and mortality. It has been demonstrated that there is no value of LDL-chol below which there ceases to be a preventive benefit with its reduction, and neither has it been observed that there is a higher incidence of secondary effects associated with lower concentrations of LDL-chol. Although there is a wide range of lipid-lowering drugs available, a high percentage of patients do not achieve the desired LDL-chol levels. The high-potency statins reduce the LDL-chol by 15-30%, and can double the percentage of patients that reach their desired level. This combination has shown to be safe and effective in the primary and secondary prevention of cardiovascular disease. Another option is the combination of statins with exchange resins, although this requires a more complex management. The inhibition of PCSK9 protein with monoclonal antibodies reduces the LDL-chol by more than 60%, and is effective in the prevention of cardiovascular disease. However, due to its cost, its use is restricted to patients with ischaemia or familial hypercholesterolaemia that do not achieve the desired levels with conventional drugs. The evidence base as regards the benefit and safety of achieving the desired levels of LDL-chol is very wide and is still increasing. In the next few years, it may be necessary to adjust the intensity of the hypercholesterolaemia treatment to the level of vascular risk of the patients, and to the level of reduction necessary to achieve the therapeutic targets. This will result in a more effective cardiovascular prevention and in a better quality of life, particularly in the large group of patients at higher vascular risk.

Cholestyramine decreases apparent total tract macronutrient digestibility and alters fecal characteristics and metabolites of healthy adult dogs.

Absorption of dietary lipids in the small intestine is dependent on the emulsification by bile acids (BA) and the formation of chylomicrons. Cholestyramine is a common drug used in humans-and potentially dogs-to treat BA malabsorption associated with chronic diarrhea. It is known to bind BA to form insoluble complexes, preventing their reabsorption and possibly proper emulsification and absorption of dietary fats. The objective of this study was to evaluate the effects of cholestyramine on 1) macronutrient apparent total tract digestibility (ATTD), and 2) fecal characteristics and metabolites of healthy adult dogs. We hypothesized that cholestyramine would decrease ATTD of fat and organic matter (OM), increase fecal dry matter (DM) content, and increase fecal output. Twelve healthy beagles (3.2 ± 0.8 yr; 10.4 ± 0.9 kg) were used in a randomized crossover design. All procedures were approved by the University of Illinois Institutional Animal Care and Use Committee before the study. The study included a baseline period and two 14-d experimental periods separated by a 14-d washout. All dogs were fed the same experimental diet, formulated to meet all nutrient needs recommended by AAFCO, throughout the study. Dogs were randomized into 2 groups [diet only (control) or diet + 11.4 g/d cholestyramine (8 g/d active ingredient)] in Period 1 and received the other treatment in Period 2. During the washout, all dogs were fed the diet only. Dogs were fed once daily (0800 h) to maintain BW. Total fecal output was collected during the last 4 d of each period for ATTD analysis. On day 14 of each of period, fresh fecal and blood samples were collected for metabolite analysis. Dogs fed cholestyramine had lower (P < 0.001) ATTD of DM, OM, energy, crude protein, and fat and lower (P < 0.01) fecal scores (firmer stools) than controls. Dogs fed cholestyramine had greater (P < 0.01) as-is and dry fecal output than controls. Dogs fed cholestyramine had lower (P < 0.05) fecal ammonia and phenol concentrations, but greater (P < 0.05) fecal indole, acetate, butyrate, and total short-chain fatty acid concentrations than controls. Fecal DM% and pH were greater (P < 0.01) in dogs fed cholestyramine. Our results indicate that cholestyramine, when given with a meal, is safe and well tolerated but significantly decreases nutrient digestibility and alters fecal characteristics. Future studies are required to explore the effects of cholestyramine on dogs with gastrointestinal disease.

Understanding and Treating Pruritus in Primary Biliary Cholangitis.

Pruritus is a common symptom with primary biliary cholangitis. Research has focused on refining understanding of the neurohumoral pathways involved in transduction of pruritus from peripheral cutaneous receptors to the central nervous system, and identifying modulating drugs. Current treatments have variable efficacy and safety. Because of the deleterious effects on quality of life or debilitation, many patients necessitate individualized therapeutic approaches; clinicians may need to consider invasive treatment options. This article highlights various therapeutic interventions, from general measures to invasive strategies, and novel agents under investigation, providing clinicians with the management tricks of the trade.

Management of Chronic Hepatic Itch.

Hepatic itch remains among the most agonizing symptoms for affected patients and a major clinical challenge for physicians. Pruritus may occur in almost all liver diseases, particularly those with cholestatic features. Hepatic itch arises irrespective of the severity of the underlying liver disease or extent of cholestasis. Antihistamines are ineffective in hepatic itch. Therapeutic recommendations consist of a guideline-based stepwise approach, starting with the anion exchange resin cholestyramine, followed by rifampicin, naltrexone, and sertraline. Bezafibrate and ileal bile acid transporter inhibitors are promising future treatment options. Experimental and invasive procedures should be reserved for refractory pruritus.

[Physiopathology and management of cholestatic pruritus in children]. / Physiopathologie et prise en charge thérapeutique du prurit cholestatique de l'enfant.

Pruritus is a disabling symptom accompanying chronic cholestasis. In some cases, refractory pruritus may require invasive therapies including liver transplantation. The pathogenesis of pruritus in cholestatic disease is poorly understood. It may involve a specific neural pathway and several pruritogenic substances such as bile acids, opioids, serotonin, and the more recently identified lysophosphatidic acid. While the therapeutic management of cholestatic pruritus is well established in adult patients, there is no consensus in children, given the difficulty in conducting controlled clinical studies. The currently recommended strategy to manage cholestatic pruritus in children is based on several lines of therapy that should always be associated with local cutaneous care and with nonspecific treatment of cholestasis including ursodeoxycholic acid therapy. Pruritus should be assessed as objectively as possible between each therapeutic step. Rifampicin, an enzyme inducer, is the specific first-line treatment of cholestatic pruritus. The second-line therapies require evaluation of the child in an expert center and are discussed on a case-by-case basis depending on the underlying disease, the experience of the center and the will of the child and his family. It could be inhibitors of serotonin reuptake (sertraline) or an opioid antagonist (naloxone). Invasive therapies such as biliary diversion or liver transplantation can also be proposed in the most severe cases.

Diagnosis and Management of Microscopic Colitis.

Microscopic colitis (MC) is a relatively common cause of chronic watery diarrhea, especially in older persons. Associated symptoms, including abdominal pain and arthralgias, are common. The diagnosis is based upon characteristic histological findings in the presence of diarrhea. The two types of MC, collagenous and lymphocytic colitis, share similar clinical features, with the main difference being the presence or absence of a thickened subepithelial collagen band. There are several treatment options for patients with MC, although only budesonide has been well studied in multiple controlled clinical trials. This review will describe the clinical features, epidemiology, pathophysiology, diagnostic criteria, and treatment of patients with MC.

Itch Management: Systemic Agents.

Itch is a global clinical problem and finding effective treatment remains a therapeutic challenge because of the complex pathophysiology of itch. The key component of treating itch should be directed at the underlying etiologies when possible. However, without eradication of the underlying diseases, treatment is often palliative at best. Treatment with systemic therapies can vary according to the etiology of the chronic itch. The aim of this article is to review the major systemic anti-itch agents and give a summary on the possible systemic treatments for different types of itch.

Cholestatic Itch Management.

Cholestatic itch is a feature of numerous hepatobiliary disorders such as primary biliary cirrhosis, primary sclerosing cholangitis, the inherited form of cholestasis, and intrahepatic cholestasis of pregnancy. Although undervalued by physicians, cholestatic itch can be a source of great discomfort to the patient and significantly affects quality of life. Many pruritogens such as bile salts, opioids, serotonin, and histamine have been implicated in the pathogenesis of cholestatic itch, but no causative link has ever been established. Recent findings indicate that the potent neuronal activator lysophosphatidic acid and autotaxin, the enzyme forming lysophosphatidic acid, may be key elements in its pathogenesis. Treatment options for patients with cholestatic itch include the anion exchange resin cholestyramine, bile acid ursodeoxycholic acid, PXR agonist rifampicin, opioid antagonist naltrexone, and the serotonin inhibitor sertraline. These drugs can be used as a stepwise therapeutic approach. The body of evidence for many of these options, however, is not very robust. Patients who do not respond to medical therapy can be candidates for interventional measures, such as albumin dialysis, plasmapheresis, or nasobiliary drainage, or certain experimental approaches such as UVB phototherapy. Research over the past decade has elucidated many of the receptors and neuropeptides involved in itch sensation and transmission; it is hoped that in the future this will lead to the development of novel antipruritic medication for cholestatic itch.

Bile cast nephropathy: A case report and review of the literature.

Bile cast nephropathy is a condition of renal dysfunction in the setting of hyperbilirubinemia. There are very few cases of this condition reported in the last decade and a lack of established treatment guidelines. While the exact etiology remains unknown, bile cast nephropathy is presumed to be secondary to multiple concurrent insults to the kidney including direct toxicity from bile acids, obstructive physiology from bile casts, and systemic hypoperfusion from vasodilation. Therapy directed at bilirubin reduction may improve renal function, but will likely need dialysis or plasmapheresis as well. We report our case of bile cast nephropathy and the therapeutic measures undertaken in a middle-aged male with chronic renal insufficiency that developed hyperbilirubinemia and drug-induced liver injury secondary to antibiotic use. He developed acute renal injury in the setting of rising bilirubin. He subsequently had a progressive decline in renal and hepatic function, requiring dialysis and plasmapheresis with some improvement, ultimately requiring transplantation.

Long-term outcomes in patients diagnosed with bile-acid diarrhoea.

OBJECTIVE: Bile-acid diarrhoea (BAD) is a recognized cause of chronic diarrhoea; however, its detection remains suboptimal. Currently, there is a paucity of follow-up studies evaluating BAD. This work evaluates the natural history of BAD by examining individuals diagnosed with BAD [7 days of Se-homocholic acid taurine (SeHCAT) retention<10%] and determining the use of and response to bile-acid sequestrants (BAS). MATERIALS AND METHODS: Of the 515 patients, 40% (207/515) who underwent an SeHCAT test at Sheffield Teaching Hospitals (2001-2012) for chronic diarrhoea had BAD. Of the 207 (51%) patients, 107 were diagnosed between 2001 and 2009. In accordance with the guidelines, all of these patients were commenced on BAS. In March 2013, these individuals were reassessed either in the clinic or over the telephone as part of a local service evaluation project. Comparisons were made of both pretreatment and post-treatment variables using a Wilcoxon rank test. RESULTS: Of the 107 patients, 54% (58/107) were followed up, with a median time since diagnosis of 6 years. Among them, 38% were still using BAS at follow-up, with 28% using alternative antidiarrhoeals. The median stool frequency decreased from seven stools per day to three (P=0.0008) in those using BAS. The 34% of patients not receiving treatment had no change in their daily bowel frequency. The main reason for discontinuing treatment was poor tolerability of the BAS (colestyramine/colestipol). CONCLUSION: Our findings indicate that BAD is a chronic condition that best improves with BAS. Consideration should be given to therapeutic options that have a better tolerability profile.

Role of Cholestyramine in Refractory Hyperthyroidism: A Case Report and Literature Review.

BACKGROUND: Hyperthyroidism is a common disease that usually responds to the conventional therapy of anti-thyroidal medications (methimazole or PTU) and beta-blocker. Refractory hyperthyroidism is a rare condition in which hyperthyroidism fails to respond to the above therapy. Cholestyramine has been shown to decrease thyroid hormone level when added to the ongoing anti-thyroidal medications. CASE REPORT: A 52-year-old woman with past medical history of enlarging goiter presented with obstructive symptoms of worsening shortness of breath and snoring. Admission thyroid function test showed mild hyperthyroidism (suppressed TSH, slightly high FT4, and high normal FT3) that worsened after she received a CT scan with contrast and failed to respond to a 3-week course of high-dose dexamethasone, high-dose carbimazole, and up-titrated propranolol. Five days after cholestyramine was added, her FT4 decreased by 30% and normalized after 12 days. The patient underwent total thyroidectomy as definitive treatment for the hyperthyroidism and for the obstructive symptoms. CONCLUSIONS: Cholestyramine is an effective additional treatment for hyperthyroidism and may be an effective treatment for refractory iodine-induced hyperthyroidism. The possibility of self-remission (natural course) is less likely given the dramatic and rapid response to cholestyramine.

Systematic review: the management of chronic diarrhoea due to bile acid malabsorption.

BACKGROUND: Bile acid malabsorption (BAM) is a common, yet under-recognised, cause of chronic diarrhoea, with limited guidance available on the appropriate management of patients with BAM. AIM: To summarise the evidence supporting different treatments available for patients with bile acid malabsorption, noting their impact on clinical outcomes, tolerability and associated side effects. METHODS: A literature search was conducted through PubMed, the Cochrane Database of Systematic Reviews and Scopus. Relevant articles studied patients who had been diagnosed with BAM and were clinically assessed before and after therapy. RESULTS: A total of 30 relevant publications (1241 adult patients) were identified, which investigated the clinical response to drugs, including colestyramine, colestipol, colesevelam, aluminium hydroxide and obeticholic acid. The most commonly used diagnostic test of bile acid malabsorption was the SeHCAT test (24 studies). Colestyramine treatment was by far the most studied of these agents, and was successful in 70% of 801 patients (range: 63-100%). CONCLUSIONS: Colestyramine and colestipol are generally effective treatments of gastrointestinal symptoms from BAM, but may be poorly tolerated and reduce the bioavailability of co-administered agents. Alternative therapies (including colesevelam and aluminium hydroxide) as well as dietary intervention may also have a role, and the promising results of the first proof-of-concept study of obeticholic acid suggest that its novel approach may have an exciting future in the treatment of this condition. Future trials should employ accurate diagnostic testing and be conducted over longer periods so that the long-term benefits and tolerability of these different approaches can be evaluated.

Bile acid malabsorption in chronic diarrhea: pathophysiology and treatment.

BACKGROUND: Bile acid malabsorption (BAM) is a common but frequently under-recognized cause of chronic diarrhea, with an estimated prevalence of 4% to 5%. METHODS: The published literature for the period 1965 to 2012 was examined for articles regarding the pathophysiology and treatment of BAM to provide an overview of the management of BAM in gastroenterology practice. RESULTS: BAM is classified as type 1 (secondary to ileal dysfunction), type 2 (idiopathic) or type 3 (secondary to gastrointestinal disorders not associated with ileal dysfunction). The estimated prevalence of BAM is >90% in patients with resected Crohn disease (CD) and 11% to 52% of unresected CD patients (type 1); 33% in diarrhea-predominant irritable bowel syndrome (type 2); and is a frequent finding postcholecystectomy or postvagotomy (type 3). Investigations include BAM fecal bile acid assay, 23-seleno-25-homo-tauro-cholic acid (SeHCAT) testing and high-performance liquid chromatography of serum 7-α-OH-4-cholesten-3-one (C4), to determine the level of bile acid synthesis. A less time-consuming and expensive alternative in practice is an empirical trial of the bile acid sequestering agent cholestyramine. An estimated 70% to 96% of chronic diarrhea patients with BAM respond to short-course cholestyramine. Adverse effects include constipation, nausea, borborygmi, flatulence, bloating and abdominal pain. Other bile acid sequestering agents, such as colestipol and colesevelam, are currently being investigated for the treatment of BAM-associated diarrhea. CONCLUSIONS: BAM is a common cause of chronic diarrhea presenting in gastroenterology practice. In accordance with current guidelines, an empirical trial of a bile acid sequestering agent is warranted as part of the clinical workup to rule out BAM.

Cholestatic liver injury associated with dietary supplements: a report of five cases in active duty service members.

The use of dietary supplements (DS) is common in the active duty population, often without physician knowledge or approval. DS have been associated with drug-induced liver injury, with rare cases resulting in liver failure or death. We report five cases of transient drug-induced liver injury temporally associated with the use of a total of six DS in active duty service members. All patients presented with elevated serum bilirubin and liver-associated enzymes: three patients had a cholestatic liver enzyme pattern, one had a hepatocellular pattern, and one had a mixed pattern. In all cases, percutaneous needle core biopsies of the liver were obtained and demonstrated a cholestatic pattern of injury with variable periportal fibrosis. Causality was considered highly probable for three cases, probable for one case, and possible for one case. Hepatotoxicity has been previously associated with four of the supplements in our cases. For the two remaining supplements, C4 Extreme and Animal Stak, we are unaware of any previous reports of hepatotoxicity. Health care professionals, in particular military physicians, should be aware of the potential risk of these supplements and be prepared to discuss these risks with their patients.

Advances in pathogenesis and treatment of pruritus.

The pathogenesis of itch during cholestasis is largely unknown and treatment options are limited. Lysophosphatidate, female steroid hormones, and endogenous opioids are among the agents discussed as potential pruritogens in cholestasis. The itch-alleviating action of guideline-based therapeutic interventions with anion exchanger resins, rifampicin, opioid antagonists, and serotonin reuptake inhibitors are studied to unravel the molecular pathogenesis of itch. Still, a considerable part of the patients is in need of alternative experimental therapeutic approaches (eg, UV-B phototherapy, extracorporeal albumin dialysis, nasobiliary drainage), providing additional information about the enigmatic pathophysiology of cholestatic pruritus.

Pruritus in chronic cholestatic liver disease.

Pruritus is a troublesome complication in patients with cholestatic liver disease. Several links to its pathogenesis have been proposed, including the role of bile acids, endogenous opioid and serotonins, and lysophosphatidic acid. The management of pruritus in cholestasis is challenging. Medical treatment of the underlying cholestatic condition may provide benefit. Extracorporeal albumin dialysis can be pursued for those who have a poor quality of life and failed the various therapeutic interventions, while awaiting liver transplantation. Experimental interventions, and the management of pruritus in certain conditions such as intrahepatic cholestasis of pregnancy and benign recurrent intrahepatic cholestasis, are also briefly reviewed.

A review of the diagnosis and treatment of Ochratoxin A inhalational exposure associated with human illness and kidney disease including focal segmental glomerulosclerosis.

Ochratoxin A (OTA) exposure via ingestion and inhalation has been described in the literature to cause kidney disease in both animals and humans. This paper reviews Ochratoxin A and its relationship to human health and kidney disease with a focus on a possible association with focal segmental glomerulosclerosis (FSGS) in humans. Prevention and treatment strategies for OTA-induced illness are also discussed, including cholestyramine, a bile-acid-binding resin used as a sequestrant to reduce the enterohepatic recirculation of OTA.

The challenge of cholestatic pruritus.

Pruritus can be the dominant symptom of cholestatic liver disease but is difficult to treat since unraveling its pathophysiology is a great challenge. Serum autotaxin activity correlates with pruritus intensity, but its causal relationship, expression pattern and exact mode of action during cholestasis remain to be established. The anion exchange resin cholestyramine, the PXR agonist rifampicin, the opioid antagonist naltrexone and the serotonine reuptake inhibitor sertraline are recommended by evidence-based guidelines as stepwise therapeutic approaches to treat itch in cholestasis. Rifampicin, the most effective antipruritic agent in cholestatic itch, has been shown to reduce autotaxin transcription in vitro. Experimental approaches include UVB phototherapy, extracorporeal albumin dialysis, nasobiliary drainage and in desperate cases even liver transplantation. Relevant clinical observations along with the different metabolic, neurologic and endocrine targets of available therapies in cholestatic pruritus are reviewed here.