The Effects of Bariatric Surgery and Gastrectomy on the Absorption of Drugs, Vitamins, and Mineral Elements

Biomonitoring of Serum Inorganic Element Concentrations in Morbidly Obese Patients: Impact of Bariatric Surgery

Adipose tissue, in addition to serving as energy storage, can store lipophilic substances, some of which may pose a health risk if massively mobilized during rapid weight loss. This study aimed to biomonitor inorganic elements in obese patients undergoing bariatric surgery and analyze the role of sociodemographic factors. ICP-MS was employed to quantify 55 elements, including elements identified from the ATSDR's Substance Priority List and rare-earth elements, in serum samples of 58 obese patients before and after bariatric surgery. A total of 39 out of 55 elements were detected, either before or after surgery, in at least one patient. Serum concentrations of gold, copper, mercury, platinum, and selenium significantly decreased after surgery. Serum concentrations of iron and zinc were significantly lower before surgery. Age, sex, diabetes status, arterial hypertension, and family history of obesity were demographic factors associated with the concentration of elements. Correlation analyses showed significant associations between elements and total lipid concentration or body mass index. Our findings indicate a complex interplay between inorganic elements and body fat and provide relevant information regarding the biomonitoring of these chemical elements in a specific and understudied population.

Economic evaluation of weight loss and transplantation strategies for kidney transplant candidates with obesity

Novel antiobesity medications, particularly glucagon-like peptide-1 receptor agonists (GLP-1RAs), have expanded weight loss (WL) options for kidney transplantation (KT) candidates with obesity beyond lifestyle modifications and bariatric surgery. However, varying effectiveness, risk profiles, and costs make strategy choices challenging. To aid decision-making, we used a Markov model to examine the cost-effectiveness of different WL strategies over a 10-year horizon. A target WL of 15% of total body weight was used for the base case scenario, and we compared these strategies to a "liberal" KT strategy of transplanting candidates with obesity. Outcomes included costs (2023 US dollars), quality-adjusted life years, and incremental cost-effectiveness ratios. In analysis, a liberal KT strategy was favored over lifestyle modifications and GLP-1RAs. Among WL strategies, bariatric surgery was the most effective and cost the least, whereas lifestyle modification had the highest cumulative costs and was the least effective. Compared to liberal KT, bariatric surgery costs $45 859 per quality-adjusted life year gained. GLP-1RAs were favored over bariatric surgery only when drug costs were below $5000 per year (base cost $12 077). In conclusion, for KT candidates with obesity, a liberal KT strategy and bariatric surgery are preferred over lifestyle modifications alone and GLP-1RAs based on outcomes and cost-effectiveness.

Effects of Testosterone Replacement Therapy on Metabolic Syndrome in Male Patients-Systematic Review

Metabolic syndrome (MS) comprises several symptoms or disorders that significantly increase the risk of developing atherosclerosis and type 2 diabetes. This study aims to determine the direct impact of testosterone therapy on the components of MS; although excluding type 2 diabetes cases. The authors conducted a systematic literature search of PubMed, Scopus, and Cochrane databases without date limits, using keywords such as "testosterone therapy", "metabolic syndrome" and "men". The studies included in our review focused on the effects of testosterone replacement therapy (TRT) in male patients with MS, yet rejecting individuals where type 2 diabetes constituted the only diagnosis. A meta-analysis was performed using PQStat v1.8.6 software. The overall effect size (mean difference) was calculated using a random effects model. Our meta-analysis indicates that testosterone therapy leads to improvement in the components of MS. Significant reductions were observed in waist circumference (WC) (95% CI: -0.709 to 0.094; p = 0.011), as well as in triglycerides (TG) (95% CI: -0.474 to 0.120; p = 0.039). These findings support the potential therapeutic benefits of testosterone treatment in managing MS. However, further research is vital to explore the long-term effects and the safety of this therapy in patients with metabolic syndrome.

Molecular Mechanisms Affecting Statin Pharmacokinetics after Bariatric Surgery

According to recent data, one in eight people in the world struggle with obesity. Obesity management is increasingly dependent on bariatric surgical interventions, as the combination of lifestyle modifications and pharmacotherapy could have a modest long-term effect. Surgery is recommended only for individuals whose body mass index (BMI) ≥ 40 kg/m2 and ≥ 35 kg/m2 in the presence of weight-related comorbidities. The most commonly performed procedures are sleeve gastrectomy and roux-en-Y gastric bypass. Pharmacokinetic and pharmacodynamic alterations occur as a result of the anatomical and physiological changes caused by surgery, which further differ depending on physicochemical drug factors and factors related to the dosage form. The following modifications are distinguished based on the type of bariatric surgery performed. Most bariatric patients have accompanying comorbidities, including dyslipidemia treated with hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins. Significant improvements in the lipid profile are observed early in the postoperative period. The data reported in this review on statin pharmacokinetic alterations have demonstrated substantial inter- and intravariability, making it difficult to adopt clear guidelines. Based on the current literature review, reducing the statin dose to the lowest effective with continuous monitoring is considered an optimal approach in clinical practice.

Outcomes of Sleeve Gastrectomy in Patients With Organ Transplant-Related Immunosuppression

INTRODUCTION

Obesity is frequent among organ transplant recipients, increasing the risk of acute graft rejection and overall morbimortality. Laparoscopic sleeve gastrectomy (LSG) effectively improves graft survival and associated comorbidities. We first compared 30-d outcomes between chronic immunosuppressed (CI) and nonchronic immunosuppressed (non-CI) patients. Then, between organ transplant and non-organ transplant CI patients who underwent LSG.

METHODS

Patients who underwent LSG within the metabolic and bariatric surgery accreditation and quality improvement program 2017-2019 were included. Using 1:1 and 1:4 propensity score matching analysis, the cohorts were matched for 30 characteristics. We then compared 30-d outcomes between CI and non-CI (analysis 1) and between organ transplant and non-organ transplant CI patients who underwent LSG (analysis 2).

RESULTS

A total of 486,576 patients were included. The matched cohorts in analysis 1 (n = 8978) and analysis 2 (n = 1152, n = 371) had similar preoperative characteristics. Propensity score matching in analysis 1 showed that patients in the CI group had significantly higher rates of renal complications (0.4% versus 0.2%, P = 0.006), unplanned intensive care unit admission (1.1% versus 0.7%, P = 0.003), blood transfusions (1.1% versus 0.7%, P = 0.003), readmissions (4.6% versus 3.5%, P < 0.001), reoperations (1.4% versus 1.0%, P = 0.033), interventions (1.3% versus 1.0%, P = 0.026), and postoperative bleeding (0.6% versus 0.4%, P = 0.013). In analysis 2, patients with organ transplant CI had a higher rate of pulmonary complications (1.1% versus 0.3%, P = 0.043), renal complications (2.4% versus 0.2%, P < 0.001), blood transfusions (6.5% versus 1.3%, P < 0.001), and readmissions (10.0% versus 4.6%, P < 0.001).

CONCLUSIONS

Patients with transplant-related CI who underwent LSG have higher 30-d postoperative complication rates compared to nontransplant-related CI patients; however, there were no differences in terms of mortality, intensive care unit admissions, staple line leaks, or bleeding. LSG is safe and feasible in this high-risk population.

Optimizing antithrombotic therapy in patients with coexisting cardiovascular and gastrointestinal disease

Balancing the safety and efficacy of antithrombotic agents in patients with gastrointestinal disorders is challenging because of the potential for interference with the absorption of antithrombotic drugs and for an increased risk of bleeding. In this Review, we address considerations for enteral antithrombotic therapy in patients with cardiovascular disease and gastrointestinal comorbidities. For those with gastrointestinal bleeding (GIB), we summarize a general scheme for risk stratification and clinical evidence on risk reduction approaches, such as limiting the use of concomitant medications that increase the risk of GIB and the potential utility of gastrointestinal protection strategies (such as proton pump inhibitors or histamine type 2 receptor antagonists). Furthermore, we summarize the best available evidence and potential gaps in our knowledge on tailoring antithrombotic therapy in patients with active or recent GIB and in those at high risk of GIB but without active or recent GIB. Finally, we review the recommendations provided by major medical societies, highlighting the crucial role of teamwork and multidisciplinary discussions to customize the antithrombotic regimen in patients with coexisting cardiovascular and gastrointestinal diseases.

Bioavailability of Orally Administered Drugs After Bariatric Surgery

PURPOSE OF REVIEW

Oral drug absorption after bariatric surgery is likely to be altered, but the impact of different bariatric surgery procedures on individual drugs is not uniform. The aim of this article is to describe factors influencing the bioavailability of orally administered drugs after bariatric surgery and to provide readers with practical recommendations for drug dosing. We also discuss the medications that may be harmful after bariatric surgery.

RECENT FINDINGS

The fundamental factors for enteral drug absorption are the production of gastric acid; the preserved length of the intestine, i.e., the size of the absorption surface and/or the preserved enterohepatic circulation; and the length of common loop where food and drugs are mixed with digestive enzymes and bile acids. Bypassing of metabolizing enzymes or efflux pumps and changes in intestinal motility can also play an important role. Significant changes of drug absorption early after the anatomic alteration may also be gradually ameliorated due to gradual intestinal adaptation. The most affected drugs are those with low or variable bioavailability and those undergoing enterohepatic circulation. Attention should also be paid to oral drug formulations, especially in the early postoperative period, when immediate-release and liquid formulations are preferred. The changes in oral bioavailability are especially clinically meaningful in patients treated with drugs possessing narrow therapeutic index (e.g., oral anticoagulants, levothyroxine, and anticonvulsants) or in acute conditions (e.g., anti-infectives); nevertheless, it may also influence the therapeutic value of chronic therapy (e.g., antidepressants. antihypertensives, antiplatelets, statins, PPIs, contraceptives, and analgesics); therapeutic effect of chronic therapy is further influenced by pharmacokinetic alterations resulting from weight loss. Therapeutic drug monitoring, periodical clinical evaluation, and adequate dose adjustments are necessary. Due to safety reasons, patients should avoid oral bisphosphonates, regular use of non-steroidal anti-inflammatory drugs, and, if possible, corticosteroids after bariatric surgery.

Safety of Non-steroidal Anti-inflammatory Drugs as Part of Enhanced Recovery After Laparoscopic Sleeve Gastrectomy-A Systematic Review and Meta-Analysis

Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric surgery option for managing extreme obesity in most patients. While non-steroidal anti-inflammatory drugs (NSAIDs) promise postoperative pain management after bariatric surgeries, their safety in LSG remains unexplored. In this systematic review, we studied the safety of NSAIDs following LSG reported by six studies involving 588 patients. Our study demonstrated that NSAIDs effectively alleviated the postoperative pain after LSG without major safety concerns. Most reported (>20% incidence) adverse events included postoperative nausea and vomiting (PONV, 21%). For patients undergoing LSG, NSAIDs offer a valuable option for pain management and improved care, potentially reducing opioid consumption. However, additional research is required to optimize NSAID usage and ensure safety, especially concerning renal and gastrointestinal issues.

The Effects of Bariatric Surgery on Pharmacokinetics of Drugs: a Review of Current Evidence

PURPOSE OF REVIEW

Obesity constitutes a major public health concern and has been recognized as an epidemic. To date, bariatric surgery remains the most effective way for substantial long-lasting weight loss in severe obesity. The purpose of this review is to summarize how the pharmacokinetics of drugs are affected by the most common types of bariatric surgery, i.e., Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG).

RECENT FINDINGS

Limited data are available regarding the changes in pharmacokinetics of drugs after bariatric surgery. The lack of existing guidelines may lead patients to experience drug toxicity or therapeutic undertreatment. Pharmacokinetic parameters that need to be taken into consideration postoperatively include gastric motility, gastric volume, pH, surface area, bile secretions, carrier proteins, and first-pass metabolism. For drugs with a narrow therapeutic index, other factors need to be monitored closely, including plasma drug levels, patients' clinical outcomes, and laboratory markers. Patients should be followed up frequently and treated in accordance with their response to the drug therapy. Bariatric surgery may affect the pharmacokinetics of various drugs, due to the resultant anatomical changes and the substantial weight loss. Therefore, there is a need to identify those potential changes and adjust patients' medication doses in order to achieve higher efficacy and avoid toxicity.

A systematic review and meta-analysis recite the efficacy of Tacrolimus treatment in renal transplant patients in association with genetic variants of CYP3A5 gene

Tacrolimus is an immunosuppressant with a narrow therapeutic index and pharmacokinetic variability. This variability may be attributed to genetic variants in gene CYP3A5 associated with Tacrolimus metabolism. Studies focusing on genetic variants in the CYP3A5 gene associated with Tacrolimus metabolism have been published, a meta-analysis of these published articles may provide a direction that can change the future research and clinical management of renal transplant patients. In this systematic review and meta-analysis, we have reviewed and analyzed the studies and clinical trials conducted to determine the association between genetic variants of CYP3A5 and Tacrolimus metabolism from the PubMed database and clinical trials (www.clinicaltrials.gov). This meta-analysis also assessed the correlation of CYP3A5 genotype (rs776746) with concentration/dose (Co/D) of Tacrolimus in renal transplant patients. The 59 published articles on genetic association of the CYP3A5 on Tacrolimus doses were reviewed for this systematic review. Meta-analysis showed that the Tacrolimus Co/D ratio is significantly lower in the CYP3A5 expressor group as compared with non-expressor in Asian, European as well as in mixed populations at any post-transplant period (P<0.0001). Our study further confirmed that the CYP3A5 variant (rs776746) is clinically relevant for the dose determination of Tacrolimus. Variations in Tacrolimus Co/D have been found to be significantly linked to the patient's CYP3A5 genetic variant (rs776746). The addition of other genetic variants involved in the pharmacokinetic of Tacrolimus may determine efficient regimen for drug dose. Our meta-analysis confirmed that the CYP3A5 genetic variant (rs776746) analysis is relevant in personalizing the Tacrolimus dose determination in renal transplant patients.

Evaluating the pharmacokinetic and pharmacodynamic impact of different modes of ticagrelor administration

INTRODUCTION

Alternative administration modes for oral P2Y12 inhibitors, particularly ticagrelor, have emerged as a potential alternative to overcome the limitations associated with the delayed onset of action of these drugs in patients who are unable to swallow or with impaired absorption.

AREAS COVERED

This comprehensive literature review aims to provide an overview of the current state of knowledge on the pharmacokinetics and administration modes of ticagrelor, including factors that may affect its action. It also compares the pharmacokinetics of ticagrelor with that of other drugs with similar uses to provide a comprehensive understanding of the potential advantages and limitations of different modalities of P2Y12 administration. For this purpose, Embase, Medline, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, Google Scholar, and ClinicalTrials.gov were searched from database inception to July 2023.

EXPERT OPINION

Among the different alternatives, crushed formulations, especially for ticagrelor, have emerged as the most promising option, showing early and robust platelet inhibition. However, important questions remain unanswered, such as the comparative clinical benefits of crushed ticagrelor versus standard administration, the cost-effectiveness of alternative modes compared to intravenous P2Y12 inhibitors such as cangrelor, and the important limitations associated with the concomitant use of opioids, who have been proven to impair even the action of crushed ticagrelor.

Micronutrient Deficiency Pre- and Post-bariatric Metabolic Surgery in Latin America: a Systematic Review

BACKGROUND

Persons submitted to bariatric metabolic surgery present micronutrient deficiency before and after surgery, due to the lack of proper supplementation. The aim of this study is to establish the prevalence of micronutrient deficiency in people before and after bariatric metabolic surgery in Latin America.

METHODS

This review was conducted in accordance with the 2020 PRISMA Guidelines.

RESULTS

Twenty-seven studies and 2135 participants were included. The highest prevalence of deficiency before surgery was reported for vitamin D (74%), zinc (71%), and hemoglobin (62%); after surgery, they were vitamin A (90.6%), vitamin D (90%), and zinc (68%).

CONCLUSIONS

There is a high prevalence of micronutrient deficiency before and after bariatric metabolic surgery from Latin American persons; the micronutrients with the highest deficiency prevalence were vitamin D before and vitamin A after bariatric metabolic surgery.

Controversial Interactions of Tacrolimus with Dietary Supplements, Herbs and Food

Tacrolimus is an immunosuppressive calcineurin inhibitor used to prevent rejection in allogeneic organ transplant recipients, such as kidney, liver, heart or lung. It is metabolized in the liver, involving the cytochrome P450 (CYP3A4) isoform CYP3A4, and is characterized by a narrow therapeutic window, dose-dependent toxicity and high inter-individual and intra-individual variability. In view of the abovementioned facts, the aim of the study is to present selected interactions between tacrolimus and the commonly used dietary supplements, herbs and food. The review was based on the available scientific literature found in the PubMed, Scopus and Cochrane databases. An increase in the serum concentration of tacrolimus can be caused by CYP3A4 inhibitors, such as grapefruit, pomelo, clementine, pomegranate, ginger and turmeric, revealing the side effects of this drug, particularly nephrotoxicity. In contrast, CYP3A4 inducers, such as St. John’s Wort, may result in a lack of therapeutic effect by reducing the drug concentration. Additionally, the use of Panax ginseng, green tea, Schisandra sphenanthera and melatonin in patients receiving tacrolimus is highly controversial. Therefore, since alternative medicine constitutes an attractive treatment option for patients, modern healthcare should emphasize the potential interactions between herbal medicines and synthetic drugs. In fact, each drug or herbal supplement should be reported by the patient to the physician (concordance) if it is taken in the course of immunosuppressive therapy, since it may affect the pharmacokinetic and pharmacodynamic parameters of other preparations.

The Impact of Bariatric-Surgery-Induced Weight Loss on Patients Undergoing Liver Transplant: A Focus on Metabolism, Pathophysiological Changes, and Outcome in Obese Patients Suffering NAFLD-Related Cirrhosis

Because of their condition, patients with morbid obesity develop several histopathological changes in the liver, such as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), cirrhosis, and end-stage liver disease (ESLD). Hence, a liver transplant (LT) becomes an opportune solution for them. Due to many challenges during the perioperative and postoperative periods, these patients are recommended to lose weight before the surgery. There are many proposals to achieve this goal, such as intragastric balloons and many different bariatric surgery (BS) procedures in combination with a preparation diet (very-low-calorie diet, ketogenic diet, etc.). All the interventions focus on losing weight and keeping the continuity and functionality of the digestive tract to avoid postoperative complications. Thus, this review analyzes recent publications regarding the metabolic and pathophysiological impacts of BS in LT patients suffering from NAFLD-related cirrhosis, the effect of weight loss on postoperative complications, and exposes the cost-effectiveness of performing BS before, after, and at liver transplantation. Finally, the authors recommend BS before the LT since there are many positive effects and better outcomes for patients who lose weight before the procedure. Nevertheless, further multicentric studies are needed to determine the generalizability of these recommendations due to their impact on public health.

Oral Potassium Malabsorption Following Bariatric Surgery

Bariatric surgery is one of the most effective long-term solutions for treating obesity due to its sustained weight loss and reduction of obesity-related comorbidities. However, nutritional deficiencies are common due to the alteration of the anatomy and physiology of the gastrointestinal tract. These include the malabsorption of macronutrients, vitamins, minerals, trace elements, and drugs. In this report, we present the case of a female patient who underwent Roux-en-Y gastric bypass surgery and subsequently developed exclusive potassium malabsorption refractory to oral replenishment.