Prednisolone absorption in coeliac disease

Impact of gastrointestinal disease states on oral drug absorption – implications for formulation design – a PEARRL review

Objectives

Drug product performance in patients with gastrointestinal (GI) diseases can be altered compared to healthy subjects due to pathophysiological changes. In this review, relevant differences in patients with inflammatory bowel diseases, coeliac disease, irritable bowel syndrome and short bowel syndrome are discussed and possible in vitro and in silico tools to predict drug product performance in this patient population are assessed.

Key findings

Drug product performance was altered in patients with GI diseases compared to healthy subjects, as assessed in a limited number of studies for some drugs. Underlying causes can be observed pathophysiological alterations such as the differences in GI transit time, the composition of the GI fluids and GI permeability. Additionally, alterations in the abundance of metabolising enzymes and transporter systems were observed. The effect of the GI diseases on each parameter is not always evident as it may depend on the location and the state of the disease. The impact of the pathophysiological change on drug bioavailability depends on the physicochemical characteristics of the drug, the pharmaceutical formulation and drug metabolism. In vitro and in silico methods to predict drug product performance in patients with GI diseases are currently limited but could be a useful tool to improve drug therapy.

Summary

Development of suitable in vitro dissolution and in silico models for patients with GI diseases can improve their drug therapy. The likeliness of the models to provide accurate predictions depends on the knowledge of pathophysiological alterations, and thus, further assessment of physiological differences is essential.

Addition of a Short Course of Prednisolone to a Gluten-Free Diet vs. Gluten-Free Diet Alone in Recovery of Celiac Disease: A Pilot Randomized Controlled Trial

Background A gluten-free diet (GFD) is the standard of care in the management of patients with celiac disease, but clinical and histological recovery are often delayed. In newly diagnosed patients, strict compliance to GFD is difficult to achieve; this is especially true in developing countries where gluten-free food is often difficult to obtain. Steroids, when used alone, can be effective in inducing recovery in patients with celiac disease. We performed a randomized controlled trial to study the effect of a short course of prednisolone combined with a GFD on the recovery of celiac disease. Materials and methods This study was a single-center, randomised, open-label trial. This investigation was done in a pediatric gastroenterology unit of a tertiary teaching hospital in north India.Twenty-eight newly diagnosed celiac disease patients were enrolled in the study. Prednisolone was given at 1 mg/kg for four weeks; duodenal biopsies and IgA anti-tissue transglutaminase (tTg) levels were assessed at eight weeks, six months, and 12 months from the start of the study. Outcome measures The primary outcome measures used to indicate clinical, histological, and immunological recovery of celiac disease were clinical improvement at eight weeks and the proportion of patients with improved histology by at least one grade and who were tissue transglutaminase (tTg) seronegative at eight weeks. The secondary measures were the proportion of patients showing normalization of histological features and the proportions of patients becoming seronegative at six months and one year of GFD. Results Patients were randomized into the GFD only (n = 14) or GFD with prednisolone (GFD+P) (n = 14) groups. No significant differences were detected in clinical recovery at eight weeks; none of the patients became seronegative at eight weeks, six months, or 12 months. The proportion of patients with improvement in histology by at least one grade was higher in the GFD+P group at eight weeks, and there was no difference in overall histological improvement at 12 months after starting treatment. Conclusion The addition of a short course of prednisolone to a GFD does not affect clinical and serological recovery but might result in rapid histological recovery compared to a GFD alone in patients newly diagnosed with celiac disease.

Effect of addition of short course of prednisolone to gluten-free diet on mucosal epithelial cell regeneration and apoptosis in celiac disease: a pilot randomized controlled trial

BACKGROUND

Identification of adjuvant treatment is necessary for rapid and effective treatment in patients with celiac disease. In a pilot randomized controlled trial, the effect of prednisolone on enterocyte apoptosis and regeneration in celiac disease was investigated.

PATIENTS AND METHODS

Thirty-three treatment-naïve patients with celiac disease were randomized to either gluten-free diet (GFD, n = 17) or GFD + prednisolone (1 mg/kg for 4 weeks, n = 16). Duodenal biopsies were taken at baseline and at 4 and 8 weeks posttreatment. Six patients with functional dyspepsia were recruited as controls. All these biopsies were stained for markers of intrinsic apoptotic pathway (AIF, H2AX, p53), common apoptotic pathway (CC3, M30), apoptotic inhibitors (XIAP, Bcl2), and epithelial proliferation (Ki-67). Apoptotic (AI) and proliferation indices (PI) were compared.

RESULTS

At baseline duodenal biopsies, the end apoptotic products H2AX and M30 were significantly increased. In comparison with those treated with GFD alone, after 4 weeks of GFD + prednisolone treatment, some markers of both intrinsic and common apoptotic pathways showed rapid decline. After prednisolone withdrawal, there was overexpression of H2AX, CC3, and p53 in the latter group. In comparison with those treated with only GFD, patients treated with prednisolone showed suppression of mucosal PI, which started rising again after withdrawal of prednisolone.

CONCLUSIONS

Apoptosis takes place in mucosal epithelium in celiac disease. Addition of short course of prednisolone suppresses apoptosis rapidly. However, it also suppresses epithelial regeneration; hence, if used, it should be withdrawn after an initial short course.

Bioavailability of prednisolone in patients with intestinal malabsorption: the importance of measuring serum protein-binding

The effect of intestinal malabsorption on the oral bioavailability of prednisolone has been studied in six patients with celiac disease and in six patients with malabsorption of various etiologies, five of whom had undergone gut resections. The serum protein-binding of prednisolone was measured in five patients with celiac disease and hypoalbuminemia and in eight healthy controls. Compared with the controls, patients with celiac disease had a 22% lower peak serum prednisolone concentration (p less than 0.05) and a 16% smaller area under the time-concentration curve of total prednisolone (NS). The proportion of free prednisolone was 79% greater in patients with celiac disease (p less than 0.01), and the area under the time-concentration curve of free, biologically active prednisolone 53% larger (p less than 0.05). There were no significant differences in peak prednisolone concentration or area under the time-concentration curve between the controls and the other patients with malabsorption, who all had normal serum albumin concentrations. These results indicate that the absorption of prednisolone in patients with malabsorption is normal and that the apparently reduced bioavailability in celiac disease patients is more likely to be due to an increased volume of distribution secondary to hypoalbuminemia and reduced protein-binding.