Orlistat associated subacute hepatic failure

Molecular modelling, synthesis and in vitro evaluation of quinazolinone hybrid analogues as potential pancreatic lipase inhibitors

Obesity is a multifactorial metabolic disorder, growing in an alarming rate across the world. Amongst the numerous targets explored for obesity management, inhibition of pancreatic lipase (PL) is considered as one of the promising approaches. Orlistat is the only PL inhibitory drug approved for long term treatment of obesity. However, it is reported to possess hepatotoxicity and nephrotoxicity. Thus, novel drug candidates that act through PL inhibition are considered the hour's need. Based on this aim, a series of quinazolinone hybrid analogues have been synthesized, characterized and evaluated for their PL inhibitory potential. The physicochemical properties and toxicity parameters suggested that these parameters are in an acceptable range for the screened analogues. Amongst the synthesised analogues, QH-25 exerted potential PL inhibition (IC50 = 16.99 ± 0.54 µM). Further, enzyme inhibition studies suggested a reversible competitive inhibition. Molecular docking of these analogues was in line with in vitro results, wherein the obtained MolDock scores exhibited a significant correlation with their inhibitory activity (Pearson's r = 0.6629). To further confirm the stability of the QH-25-PL complex in a dynamic environment, a molecular dynamics study (100 ns) was carried out and the results suggested that this complex is stable at dynamic conditions. Overall, these results shed light on the quinazolinone hybrids as potential PL inhibitors. Further structural modification may result in the development of potent anti-obesity agents which acts through PL inhibition.Communicated by Ramaswamy H. Sarma.

Anti-obesity weight loss medications: Short-term and long-term use

As obesity prevalence increases, more and more drugs that assist with weight loss have been developed. Numerous weight loss drugs had been approved, but many have also been withdrawn based on their lack of efficacy as well as safety concerns. Initial approaches in developing weight loss drugs was by increasing physiological energy expenditure and suppressing the appetite. Subsequently, as more physiological mechanisms for weight gain has been unearthed, drugs targeting newly discovered receptors and/or enzymes have been introduced with improved safety profiles and fewer psychological adverse events. Additionally, drugs targeting hunger or satiety signaling have been actively studied, and have shown increased adoption by physicians. Studies have also evaluated drugs that target metabolic tissues-such as adipose tissue or muscle-to promote weight loss, however to-date nothing has carried on into clinical practice. Starting with a brief history of early obesity treatments, this review evaluates current weight loss pharmaceutical options based on their duration of therapy status.

Pharmacotherapy for Weight Loss in Cirrhosis and Liver Transplantation: Translating the Data and Underused Potential

BACKGROUND AND AIMS

Thirty percent of patients with cirrhosis are obese and the prevalence of obesity increases after transplant to >40% post-transplant. There are currently four weight loss medications approved by the FDA for treatment of obesity (orlistat, phentermine-topiramate, naltrexone-bupropion, and liraglutide). The aim of this review was to investigate the data on the use of these weight loss medications and alternative medicines in patients with cirrhosis and in liver transplant recipients (LTRs).

APPROACH AND RESULTS

While there is paucity of data for these medications in patients with cirrhosis and LTRs, Liraglutide appears to be generally safe in view of its pharmacokinetic properties. Phentermine-topiramate seems to have the highest weight loss potential but special consideration should be given to neuropsychiatric disorders, cardiovascular comorbidities, and drug interactions. There are emerging data on use of alternative medicines for weight loss but more data are needed.

CONCLUSIONS

The use of weight loss medications is feasible in this patient population but the decision of which medication to prescribe should be individualized based on the degree of renal and hepatic impairment, other co-morbidities, and concomitant medications.

Effects of Ethanol Extracts from Grateloupia elliptica, a Red Seaweed, and Its Chlorophyll Derivative on 3T3-L1 Adipocytes: Suppression of Lipid Accumulation through Downregulation of Adipogenic Protein Expression

Grateloupia elliptica (G. elliptica) is a red seaweed with antioxidant, antidiabetic, anticancer, anti-inflammatory, and anticoagulant activities. However, the anti-obesity activity of G. elliptica has not been fully investigated. Therefore, the effect of G. elliptica ethanol extract on the suppression of intracellular lipid accumulation in 3T3-L1 cells by Oil Red O staining (ORO) was evaluated. Among the eight red seaweeds tested, G. elliptica 60% ethanol extract (GEE) exhibited the highest inhibition of lipid accumulation. GEE was the only extract to successfully suppress lipid accumulation among ethanol extracts from eight red seaweeds. In this study, we successfully isolated chlorophyll derivative (CD) from the ethyl acetate fraction (EA) of GEE by high-performance liquid chromatography and evaluated their inhibitory effect on intracellular lipid accumulation in 3T3-L1 adipocytes. CD significantly suppressed intracellular lipid accumulation. In addition, CD suppressed adipogenic protein expression such as sterol regulatory element-binding protein-1 (SREBP-1), peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding protein-α (C/EBP-α), and fatty acid binding protein 4 (FABP4). Taken together, our results indicate that CD from GEE inhibits lipid accumulation by suppressing adipogenesis via the downregulation of adipogenic protein expressions in the differentiated adipocytes. Therefore, chlorophyll from G. elliptica has a beneficial effect on lipid metabolism and it could be utilized as a potential therapeutic agent for preventing obesity.

Implications for body weight extremes in solid organ transplantation

The pharmacokinetic profiles of medications are altered in overweight and underweight patients, but few studies have described these differences in patients with body mass index extremes. As solid organ transplant programs expand their candidate selection criteria to accommodate a growing population of patients with weight extremes, it has become imperative to understand and evaluate the impact weight extremes have on the pharmacokinetics of life-sustaining immunosuppression in this population. This review will describe pharmacokinetic and dosing considerations for weight extremes in solid organ transplant recipients, including changes following bariatric surgeries, non-pharmacologic and pharmacologic management strategies for weight loss and gain, and potential drug-drug interactions with popular weight management products.

Fulminant liver failure secondary to submassive hepatic necrosis in a patient treated with Orlistat. A case report

Orlistat is an intestinal lipase inhibitor drug that is recommended in obese patients along with a hypocaloric diet. Although the most frequent secondary effect is steatorrhea, fulminant liver failure has also been associated with this drug, which has required liver transplantation in 3 patients. We present the case of a 42-year-old obese male.

Dietary sphingolipids: potential for management of dyslipidemia and nonalcoholic fatty liver disease

The development of therapeutic approaches aimed at reducing inflammation, improving lipid metabolism, and preventing nonalcoholic fatty liver disease holds significant potential in the management of obesity-associated disease. In this review, the recent basic science and clinical research examining dietary sphingolipid intake and the prevention of dyslipidemia and nonalcoholic fatty liver disease is summarized. Dietary sphingolipids have been shown to dose-dependently reduce the acute intestinal absorption of cholesterol, triglycerides, and fatty acids in rodents. Overall, studies feeding dietary sphingolipids to rodents typically show reductions in serum lipids. Furthermore, these hypolipidemic effects are also observed in most human studies, although the magnitude of such effects is typically smaller. Dietary sphingolipids also appear useful in preventing hepatic lipid uptake and accumulation and have shown benefits in preventing hepatic steatosis in rodent models. Dietary sphingolipids may affect the gut-liver axis by preventing the translocation of gut bacteria-derived lipopolysaccharide and/or inhibiting its proinflammatory effects. Current evidence from preclinical studies indicates that dietary sphingolipids have lipid-lowering and anti-inflammatory properties, although their potential to prevent human chronic disease has not been fully explored. It will be important to determine if such effects seen in cell and animal models translate to humans. More research is warranted to define how dietary sphingolipids influence lipid metabolism and inflammation.

An Unexpected Result of Obesity Treatment: Orlistat-Related Acute Pancreatitis

Orlistat is a pancreatic lipase inhibitor which is used to treat obesity. Due to the increasing prevalence of obesity, orlistat use is thought to rise progressively. We report an interesting case caused by orlistat use caught in the early stages of acute pancreatitis through imaging; in addition, the case had significantly elevated serum amylase levels. A 54-year-old male who had a history of orlistat treatment started 7 days before was admitted to the emergency department with complaints of abdominal pain, nausea and vomiting lasting for 24 h. Abdominal computed tomography revealed peripancreatic fat tissue edema and a heterogeneous appearance of the pancreas. Based on these findings, it was concluded that edematous pancreatitis was in its initial stage. Orlistat is a drug that is increasingly widespread use due to obesity. More attention must be paid when planning to prescribe orlistat to patients if there are risk factors for acute pancreatitis (alcohol use, height, serum calcium and lipid levels).

Orlistat-induced fulminant hepatic failure

Orlistat was approved by the Food and Drug Administration in 1998 and has been shown to be superior to placebo in achieving weight loss. It is generally well tolerated. However, severe liver injury has been reported. We present a case of hepatic failure in a patient taking orlistat. A 54-year-old African-American woman with hypertension presented with hepatic failure. She had noticed increasing fatigue, jaundice and confusion. She used alcohol sparingly and denied tobacco or illicit drug use, but had been taking over-the-counter orlistat for the past two months. Physical examination revealed scleral icterus, jaundice, asterixis and slow speech. Laboratory testing showed markedly abnormal liver function tests with coagulopathy. Acute viral and autoimmune serologies were negative, as was toxicology screen. Liver biopsy showed necrotic hepatic parenchyma likely secondary to drug toxicity. Based upon her clinical presentation and time course, the pattern of liver injury seen on liver biopsy and lack of an alternative plausible explanation, her liver failure was most likely associated with orlistat use. She continued to deteriorate and ultimately underwent orthotopic liver transplantation. Fourteen cases of severe liver injury associated with orlistat use have been reported, four of which are detailed in the literature. This is the second published case of liver failure associated with over-the-counter orlistat usage. Clinicians should be aware of the growing number of cases associating liver injury and orlistat use and carefully monitor their patients on this medication for signs of hepatic dysfunction.

Toxicity of weight loss agents

INTRODUCTION

With the rise of the obesity epidemic in the United States over the last several decades and the medical complications seen with it, weight loss and dieting have become a national public health concern.

DISCUSSION

Because of their increased use and availability through internet sales, several different dieting agents were reviewed for potential toxicity. These included: syrup of ipecac, cathartics, human chorionic gonadotropin hormone, 2,4 Dinitrophenol, guar gum, phenylpropanolamine, ma huang/ ephedra, caffeine, clenbuterol, fenfluramine, sibutramine, thyroid hormone, orlistat and cannabinoid antagonists.

CONCLUSIONS

With the internet making even banned products readily accessible, healthcare providers need to be aware of the potential toxicities of a wide range of weight loss agents. Our review covered topics we thought to be most historically significant as well as pertinent to the practice of medical toxicology today.

Orlistat-associated adverse effects and drug interactions: a critical review

Orlistat, an anti-obesity drug, is a potent and specific inhibitor of intestinal lipases. In light of the recent US FDA approval of the over-the-counter sale of orlistat (60 mg three times daily), clinicians need to be aware that its use may be associated with less well known, but sometimes clinically relevant, adverse effects. More specifically, the use of orlistat has been associated with several mild-to-moderate gastrointestinal adverse effects, such as oily stools, diarrhoea, abdominal pain and faecal spotting. A few cases of serious hepatic adverse effects (cholelithiasis, cholostatic hepatitis and subacute liver failure) have been reported. However, the effects of orlistat on non-alcoholic fatty liver disease are beneficial. Orlistat-induced weight loss seems to have beneficial effects on blood pressure. No effect has been observed on calcium, phosphorus, magnesium, iron, copper or zinc balance or on bone biomarkers. Interestingly, the use of orlistat has been associated with rare cases of acute kidney injury, possibly due to the increased fat malabsorption resulting from the inhibition of pancreatic and gastric lipase by orlistat, leading to the formation of soaps with calcium and resulting in increased free oxalate absorption and enteric hyperoxaluria. Orlistat has a beneficial effect on carbohydrate metabolism. No significant effect on cancer risk has been reported with orlistat.Orlistat interferes with the absorption of many drugs (such as warfarin, amiodarone, ciclosporin and thyroxine as well as fat-soluble vitamins), affecting their bioavailability and effectiveness. This review considers orlistat-related adverse effects and drug interactions. The clinical relevance and pathogenesis of these effects is also discussed.

The safety profiles of orlistat and sibutramine: results of prescription-event monitoring studies in England

INTRODUCTION

Observational cohort studies were conducted using prescription-event monitoring (PEM) to examine the safety profiles of the anti-obesity agents orlistat and sibutramine. Adverse events reported as case reports were also evaluated to determine whether these events were also identified by PEM.

RESEARCH METHODS AND PROCEDURES

Patients were identified from dispensed prescriptions written by general practitioners (GPs) in England for orlistat or sibutramine. Patient demographic and clinical event information, including reasons for stopping and adverse drug reactions, were requested on questionnaires posted to GPs at least 6 months after the first prescription for individual patients. Event incidence densities (IDs) (number of first reports of event/1000 patient-months treatment) were calculated for month 1 (ID(1)) and months 2-3 (ID(2-3)). Published case reports were identified by searching Medline and Embase.

RESULTS

The cohorts comprised 16,021 and 12,336 patients prescribed orlistat and sibutramine, respectively. Both cohorts had a median age of 45 years, and approximately 80% were female. The most common reason for stopping orlistat within 3 months was diarrhea (332 patients; 2.1% cohort), and for stopping sibutramine it was hypertension (203 patients; 1.6%). Clinical events significantly associated with taking orlistat were mainly gastrointestinal and those for sibutramine included central nervous system effects, nausea/vomiting, palpitation, and sweating. We identified 8 published case reports for orlistat and 10 for sibutramine that had equivalent or similar events assessed as causally related in the PEM studies.

CONCLUSIONS

The PEM studies highlighted different adverse event profiles for orlistat and sibutramine that were consistent with their distinct pharmacological mechanisms and other published information.

Orlistat treatment is safe in overweight and obese liver transplant recipients: a prospective, open label trial

Obesity is a frequent complication following liver transplantation and is insufficiently responsive to dietary and life style advice. We studied the safety of orlistat treatment in obese and overweight liver transplant recipients (n = 15) on a stable tacrolimus-based immunosuppressive regimen. For safety reasons, the treatment period was restricted (6 months 120 mg t.i.d., 3 months 120 mg daily). Three patients dropped out, tacrolimus dose was adjusted in six of 12 remaining patients (dose reduction in 4, increase in 2, P = N.S.). All dose adjustments occurred during the 6 months of orlistat 120 mg t.i.d. therapy. No drug intolerance, adverse events or episodes of rejection occurred during the study. Efficacy of orlistat treatment in this population could not be shown, because a formal control population was not included in this safety trial. Moreover, only a significant decrease of waist circumference (P < 0.01 versus start of the study), but not of weight or body mass index, was achieved in the treated group. Orlistat treatment is well tolerated in liver transplant recipients and can be started safely, provided immunosuppressive drug levels and dietary adherence are closely monitored.

Use of orlistat (xenical) to treat chylous ascites

Chylous ascites is uncommon and occurs in about 1 in 20,000 hospital admissions. Causes include disruption of the lymphatic system due to malignancy, cirrhosis, surgery, or radiation therapy. The mainstay of therapy has been low-fat diet supplemented with medium-chain triglyceride oil. However, dietary compliance can be difficult to achieve for adequate response. We report a 47-year-old man with hepatitis C and alcohol-related cirrhosis with new-onset chylous ascites and chylothorax. His ascites triglyceride was 585 mg/dL, and the pleural fluid triglyceride was 691 mg/dL. Ascitic and pleural fluid cytology and acid-fast bacilli stain were negative. The patient was treated with low-fat diet and medium-chain triglyceride oil. However, his ascites remained chylous after 1 week of treatment because of poor compliance with the dietary restrictions. Orlistat was then added to his treatment regimen. A half week later, the chylous component of his ascites resolved. Remaining high-volume clear ascites was treated with placement of a transjugular intrahepatic portosystemic shunt. To our knowledge, orlistat has never been used in the treatment of chylous ascites. This case suggests the potential value of adding orlistat to low-fat diet and medium-chain triglyceride oil in the treatment of chylous ascites, especially in patients who are unable to comply with the dietary restrictions.