First Case Report of Fulminant Hepatitis After Laparoscopic Sleeve Gastrectomy Associated with Concomitant Maximal Therapeutic Dose of Acetaminophen Use, Protein Calorie Malnutrition, and Vitamins A and D, Selenium, and Glutathione Deficiencies

Pharmacokinetics after bariatric surgery: adverse effects and drug safety issues in bariatric patients

INTRODUCTION

Medication management after bariatric surgery is a major and complex challenge. The altered gastrointestinal anatomy/physiology post-surgery may impact oral drug absorption/pharmacokinetics, with potential clinical implications. Along with multiple studies/cases of impaired post-surgery drug absorption/pharmacokinetics, leading to potential treatment failure, reports of increased drug exposure, leading to post-bariatric safety issues and adverse effects risk, are also available; yet, this second scenario of increased post-surgery drug levels, is less familiar in practice.

AREAS COVERED

In this article, we highlight and overview the literature reports of increased post-bariatric drug exposure and safety issues, and discuss the underlying relevant mechanisms. Finally, we provide clinical recommendations for managing this therapeutic challenge.

EXPERT OPINION

Around 25 drugs were found to exhibit post-bariatric enhanced pharmacokinetics and risk of adverse effects. Among them, toxicity with lithium treatment is well-established. Clear safety concerns were also raised for other drugs, including levothyroxine, atorvastatin, paracetamol and, importantly, immediate-release morphine. Cautious use, while closely monitoring clinical signs of toxicity, is advised for these drugs. Realizing the potentially altered post-bariatric pharmacokinetics of various drugs, and, in particular, the risk of increased exposure with related adverse effects, is essential for providing optimal pharmacological therapy and overall patient care to the growing bariatric population.

Acetaminophen-Induced Hepatotoxicity in Obesity and Nonalcoholic Fatty Liver Disease: A Critical Review

The epidemic of obesity, type 2 diabetes and nonalcoholic liver disease (NAFLD) favors drug consumption, which augments the risk of adverse events including liver injury. For more than 30 years, a series of experimental and clinical investigations reported or suggested that the common pain reliever acetaminophen (APAP) could be more hepatotoxic in obesity and related metabolic diseases, at least after an overdose. Nonetheless, several investigations did not reproduce these data. This discrepancy might come from the extent of obesity and steatosis, accumulation of specific lipid species, mitochondrial dysfunction and diabetes-related parameters such as ketonemia and hyperglycemia. Among these factors, some of them seem pivotal for the induction of cytochrome P450 2E1 (CYP2E1), which favors the conversion of APAP to the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI). In contrast, other factors might explain why obesity and NAFLD are not always associated with more frequent or more severe APAP-induced acute hepatotoxicity, such as increased volume of distribution in the body, higher hepatic glucuronidation and reduced CYP3A4 activity. Accordingly, the occurrence and outcome of APAP-induced liver injury in an obese individual with NAFLD would depend on a delicate balance between metabolic factors that augment the generation of NAPQI and others that can mitigate hepatotoxicity.