Effects of infliximab and parenteral nutrition on albumin and fibrinogen synthesis rates in pediatric Crohn disease

Applications of stable isotopes in clinical pharmacology

This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the pharmacokinetic profile or mode of action of a drug substance. Secondly, stable isotopes may be used for the assessment of drug products or drug delivery systems by determination of parameters such as the bioavailability or the release profile. Thirdly, patients may be assessed in relation to patient-specific drug treatment; this concept is often called personalized medicine. In this article, the application of stable isotope technology in the aforementioned three areas is reviewed, with emphasis on developments over the past 25 years. The applications are illustrated with examples from clinical studies in humans.

Nutrition in inflammatory bowel disease

The diet of industrialized nations may contribute to the pathogenesis of both ulcerative colitis (UC) and Crohn disease (CD). Malnutrition is relatively unusual in UC, but in CD, which often affects the small intestine, it is frequent and may be severe. Nutrition support is therefore frequently indicated. First principles of artificial nutrition can be applied effectively using the gut whenever possible. Parenteral nutrition is generally required only in those with short bowel syndrome. An increasing literature (especially in pediatrics) favors the use of defined exclusive enteral nutrition (EN) in the primary treatment of active CD. Controlled trials are, however, lacking, and recommendations are accordingly not of the highest rank. It appears that in this context, simple polymeric regimens are usually sufficient, and there is currently insufficient evidence to make a strong recommendation for disease-specific feeds. In the maintenance of remission in CD, controlled data demonstrate that defined EN reduces the risk of relapse requiring steroid treatment. There are no data in support of primary nutrition therapy in UC either in management of the acute flare or in maintenance. In conclusion, nutrition therapy in adults with inflammatory bowel disease is probably both undervalued and underused, but the evidence base needs to be strengthened to confirm its efficacy, determine better those patients most likely to benefit, and optimize the regimens to be employed.

Use of biologic agents in pediatric inflammatory bowel disease

PURPOSE OF REVIEW

Owing to its aggressive clinical course and associated immunologic abnormalities, pediatric inflammatory bowel disease (IBD) is increasingly managed with immunomodulators and biologic agents. Clinical experience with therapy targeted against tumor necrosis factor-alpha has raised important questions about these agents, which will be addressed in this review.

RECENT FINDINGS

Pediatric IBD is increasingly appreciated to have a variety of recognized clinical phenotypes that are associated with particular genotypes and serologic responses. These observations may ultimately allow individualized therapy that could change the natural history of pediatric IBD and reverse its severe metabolic and growth effects. Several new studies suggest that antitumor necrosis factor therapy could be an important part of this therapeutic vista. In addition to shedding light on who could best benefit from such agents, optimization of such therapy and its safety have been active areas of recent research.

SUMMARY

Biologic therapy for pediatric IBD is an increasingly employed strategy. The aggressive nature of the disease and its consequent metabolic effects make this an attractive option for many patients. Recent research is helping guide the clinician to identify who could best benefit from such therapy while also exploring its safety and ideal dosing strategy.