Impact of gastrointestinal physiology on drug absorption in special populations--An UNGAP review.

The release and absorption profile of an oral medication is influenced by the physicochemical properties of the drug and its formulation, as well as by the anatomy and physiology of the gastrointestinal (GI) tract. During drug development the bioavailability of a new drug is typically assessed in early clinical studies in a healthy adult population. However, many disease conditions are associated with an alteration of the anatomy and/or physiology of the GI tract.

Predicting iron absorption from an effervescent iron supplement in obese patients before and after Roux-en-Y gastric bypass: a preliminary study.

Background & Aims: Oral iron absorption is hampered in obese and bariatric patients, especially after Roux-en-Y gastric bypass (RYGB). As a result, iron deficiency, which is common in both patient groups, can be difficult to treat by oral supplements, often necessitating a switch to parenteral administration. The aim of this study was to find possible predictors of the extent of absorption of an effervescent iron gluconate oral supplement, which enables to pre-emptively identify those patients in which oral supplementation is likely to fail.

At similar weight loss, dietary composition determines the degree of glycemic improvement in diet-induced obese C57BL/6 mice.

Background: Achieving weight loss is the cornerstone of the treatment of the metabolic consequences of obesity, in particular of glucose intolerance.

Objective: To determine whether improvement in glucose control depends on dietary macronutrient composition of the diet at identical weight loss.

Materials And Methods: Twenty-two weeks old diet-induced obese C57BL/6 mice lost weight through caloric restriction on normal chow (R-NC) or high fat diet (R-HF).

The relevance of dietary protein after bariatric surgery: what do we know?

Purpose Of Review: The growing obesity epidemic is associated with an increased demand for bariatric surgery with Roux-en-Y Gastric Bypass and Sleeve Gastrectomy as the most widely performed procedures. Despite beneficial consequences, nutritional complications may arise because of anatomical and physiological changes of the gastrointestinal tract. The purpose of this review is to provide an update of the recent additions to our understanding of the impact of bariatric surgery on the intake, digestion and absorption of dietary protein.

Micronutrient intake, from diet and supplements, and association with status markers in pre- and post-RYGB patients.

Background & Aims: Roux-en-Y gastric bypass (RYGB) is associated with an increased risk for micronutrient deficiencies. This study aimed to assess total (dietary and supplement) intake and association with iron (including hepcidin), vitamin B, vitamin C and zinc status markers before and after Roux-en-Y gastric bypass (RYGB).

Methods: This prospective study included patients with a planned RYGB in University Hospitals Leuven, Belgium; who were followed until 12 months post-RYGB.

Drug disposition before and after gastric bypass: fenofibrate and posaconazole.

Aims: Roux-en-Y gastric bypass (RYGB) alters the anatomical structure of the gastrointestinal tract, which can result in alterations in drug disposition. The aim of the present study was to evaluate the oral disposition of two compounds belonging to the Biopharmaceutical Classification System Class II - fenofibrate (bile salt-dependent solubility) and posaconazole (gastric pH-dependent dissolution) - before and after RYGB in the same individuals.

Methods: A single-dose pharmacokinetic study with two model compounds - namely, 67 mg fenofibrate (Lipanthyl®) and 400 mg posaconazole (Noxafil®) - was performed in 12 volunteers pre- and post-RYGB.

Drug disposition and modelling before and after gastric bypass: immediate and controlled-release metoprolol formulations.

Aims: The aim of the present study was to evaluate the disposition of metoprolol after oral administration of an immediate and controlled-release formulation before and after Roux-en-Y gastric bypass (RYGB) surgery in the same individuals and to validate a physiologically based pharmacokinetic (PBPK) model for predicting oral bioavailability following RYGB.

Methods: A single-dose pharmacokinetic study of metoprolol tartrate 200 mg immediate release and controlled release was performed in 14 volunteers before and 6-8 months after RYGB. The observed data were compared with predicted results from the PBPK modelling and simulation of metoprolol tartrate immediate and controlled-release formulation before and after RYGB.

Barriers in the Approach of Obese Patients Undergoing Bariatric Surgery in Flemish Hospitals.

Background: Bariatric surgery is associated not only with weight loss and improvement of comorbidities of obesity but also with short and long-term complications. Preoperative screening and lifelong follow-up of these patients are important to optimize the effect of bariatric surgery and minimize complications. The objective of this study was to create an inventory of the current care offered to bariatric patients before and after surgery in Flemish hospitals, Belgium and to identify barriers for optimal care.

Medication cost is significantly reduced after Roux-en-Y gastric bypass in obese patients.

Background: This study aims to determine the influence of Roux-en-Y gastric bypass (RYGB) on medication-related costs.

Methods: The study analyzed the types, dosages, and costs of drugs and medical devices prescribed before and after surgery (1, 3, 6, and 12 months and yearly thereafter) in patients who underwent RYGB between June 2004 and May 2010 and had an outpatient visit between December 2009 and May 2010 at Pitié-Salpêtrière University Hospital, Paris, France.

Results: The cohort included 143 patients (78 % female; mean age, 42.

Iron deficiency after Roux-en-Y gastric bypass: insufficient iron absorption from oral iron supplements.

Background: Roux-en-Y gastric bypass (RYGB) may reduce the absorption of iron, but the extent to which this absorption is impeded is largely unknown. First, we determined the prevalence of iron deficiency following RYGB and explored the risk factors for its development. Second, we examined to what extent oral iron supplements are absorbed after RYGB.