Ranitidine and omeprazole as adjuvant therapy to pancrelipase to improve fat absorption in patients with cystic fibrosis

Coefficient of Fat Absorption to Measure the Efficacy of Pancreatic Enzyme Replacement Therapy in People With Cystic Fibrosis: Gold Standard or Coal Standard?

OBJECTIVES

We sought data on the validity, reliability, responsiveness, and feasibility of the coefficient of fat absorption (CFA) as a measure of pancreatic enzyme replacement therapy (PERT) efficacy in people with cystic fibrosis (pwCF) and reviewed the literature for alternative measures.

METHODS

We searched PubMed for the Medical Subject Heading cystic fibrosis and the key words cystic fibrosis, fat absorption, CFA, and fecal fat imbalance; historical articles; and citations in bibliographies.

RESULTS

The lower the CFA, the greater its variability; thus, it is less variable in healthy individuals who have higher CFA than pwCF. In addition, the test-retest values for CFA are more variable in pwCF than the general population. There is no correlation between CFA and body mass index or PERT dose but CFA is related to gastrointestinal signs and symptoms. Research-quality CFA studies are expensive, time consuming, and odious to pwCF and research staff. Sparse stool tests, breath tests, and blood tests of fat absorption have been studied as potential alternatives to CFA to measure PERT efficacy.

CONCLUSIONS

Based on the evidence, we conclude that CFA as a measure of the efficacy of PERT is more of a "coal standard" than a gold standard; developing suitable alternatives should be a priority.

Drug therapies for reducing gastric acidity in people with cystic fibrosis

BACKGROUND

Malabsorption of fat and protein contributes to poor nutritional status in people with cystic fibrosis. Impaired pancreatic function may also result in increased gastric acidity, leading in turn to heartburn, peptic ulcers and the impairment of oral pancreatic enzyme replacement therapy. The administration of gastric acid-reducing agents has been used as an adjunct to pancreatic enzyme therapy to improve absorption of fat and gastro-intestinal symptoms in people with cystic fibrosis. It is important to establish the evidence regarding potential benefits of drugs that reduce gastric acidity in people with cystic fibrosis. This is an update of a previously published review.

OBJECTIVES

To assess the effect of drug therapies for reducing gastric acidity for: nutritional status; symptoms associated with increased gastric acidity; fat absorption; lung function; quality of life and survival; and to determine if any adverse effects are associated with their use.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic and non-electronic database searches, handsearches of relevant journals,  abstract books and conference proceedings. Both authors double checked the reference lists of the searches Most recent search of the Group's Trials Register: 26 April 2021. On the 26 April 2021 further searches were conducted on the clinicaltrials.gov register to identify any ongoing trials that may be of relevance. The WHO ICTRP database was last searched in 2020 and is not currently available for searching due to the Covid-19 pandemic.

SELECTION CRITERIA

All randomised and quasi-randomised trials involving agents that reduce gastric acidity compared to placebo or a comparator treatment.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed trial quality and extracted data.

MAIN RESULTS

The searches identified 40 trials; 17 of these, with 273 participants, were suitable for inclusion, but the number of trials assessing each of the different agents was small. Seven trials were limited to children and four trials enrolled only adults. Meta-analysis was not performed, 14 trials were of a cross-over design and we did not have the appropriate information to conduct comprehensive meta-analyses. All the trials were run in single centres and duration ranged from five days to six months. The included trials were generally not reported adequately enough to allow judgements on risk of bias. However, one trial found that drug therapies that reduce gastric acidity improved gastro-intestinal symptoms such as abdominal pain; seven trials reported significant improvement in measures of fat malabsorption; and two trials reported no significant improvement in nutritional status. Only one trial reported measures of respiratory function and one trial reported an adverse effect with prostaglandin E2 analogue misoprostol. No trials have been identified assessing the effectiveness of these agents in improving quality of life, the complications of increased gastric acidity, or survival.

AUTHORS' CONCLUSIONS

Trials have shown limited evidence that agents that reduce gastric acidity are associated with improvement in gastro-intestinal symptoms and fat absorption. Currently, there is insufficient evidence to indicate whether there is an improvement in nutritional status, lung function, quality of life, or survival. Furthermore, due to the unclear risks of bias in the included trials, we are unable to make firm conclusions based on the evidence reported therein. We therefore recommend that large, multicentre, randomised controlled clinical trials are undertaken to evaluate these interventions.

Practical guide to exocrine pancreatic insufficiency - Breaking the myths

BACKGROUND

Exocrine pancreatic insufficiency (EPI) is characterized by a deficiency of exocrine pancreatic enzymes, resulting in malabsorption. Numerous conditions account for the etiology of EPI, with the most common being diseases of the pancreatic parenchyma including chronic pancreatitis, cystic fibrosis, and a history of extensive necrotizing acute pancreatitis. Treatment for EPI includes dietary management, lifestyle changes (i.e., decrease in alcohol consumption and smoking cessation), and pancreatic enzyme replacement therapy.

DISCUSSION

Many diagnostic tests are available to diagnose EPI, however, the criteria of choice remain unclear and the causes for a false-positive test are not yet understood. Despite multiple studies on the treatment of EPI using exogenous pancreatic enzymes, there remains confusion amongst medical practitioners with regard to the best approach to diagnose EPI, as well as dosing and administration of pancreatic enzymes. Appropriate use of diagnostics and treatment approaches using pancreatic enzymes in EPI is essential for patients. This opinion piece aims to address the existing myths, remove the current confusion, and function as a practical guide to the diagnosis and treatment of EPI.

Enteral tube feeding for individuals with cystic fibrosis: Cystic Fibrosis Foundation evidence-informed guidelines

Nutrition is integral to the care of individuals with cystic fibrosis (CF). Better nutritional status is associated with improved pulmonary function. In some individuals with CF, enteral tube feeding can be useful in achieving optimal nutritional status. Current nutrition guidelines do not include detailed recommendations for enteral tube feeding. The Cystic Fibrosis Foundation convened an expert panel to develop enteral tube feeding recommendations based on a systematic review of the evidence and expert opinion. These guidelines address when to consider enteral tube feeding, assessment of confounding causes of poor nutrition in CF, preparation of the patient for placement of the enteral feeding tube, management of the tube after placement and education about enteral feeding. These recommendations are intended to guide the CF care team, individuals with CF, and their families through the enteral tube feeding process.

Drug therapies for reducing gastric acidity in people with cystic fibrosis

BACKGROUND

Malabsorption of fat and protein contributes to poor nutritional status in people with cystic fibrosis. Impaired pancreatic function may also result in increased gastric acidity, leading in turn to heartburn, peptic ulcers and the impairment of oral pancreatic enzyme replacement therapy. The administration of gastric acid-reducing agents has been used as an adjunct to pancreatic enzyme therapy to improve absorption of fat and gastro-intestinal symptoms in people with cystic fibrosis. It is important to establish the evidence regarding potential benefits of drugs that reduce gastric acidity in people with cystic fibrosis. This is an update of a previously published review.

OBJECTIVES

To assess the effect of drug therapies for reducing gastric acidity for: nutritional status; symptoms associated with increased gastric acidity; fat absorption; lung function; quality of life and survival; and to determine if any adverse effects are associated with their use.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals, abstract books and conference proceedings.Most recent search of the Group's Trials Register: 12 May 2016.

SELECTION CRITERIA

All randomised and quasi-randomised trials involving agents that reduce gastric acidity compared to placebo or a comparator treatment.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed trial quality and extracted data.

MAIN RESULTS

The searches identified 39 trials; 17 of these, with 273 participants, were suitable for inclusion, but the number of trials assessing each of the different agents was small. Seven trials were limited to children and four trials enrolled only adults. Meta-analysis was not performed, 14 trials were of a cross-over design and we did not have the appropriate information to conduct comprehensive meta-analyses. All the trials were run in single centres and duration ranged from five days to six months. The included trials were generally not reported adequately enough to allow judgements on risk of bias.However, one trial found that drug therapies that reduce gastric acidity improved gastro-intestinal symptoms such as abdominal pain; seven trials reported significant improvement in measures of fat malabsorption; and two trials reported no significant improvement in nutritional status. Only one trial reported measures of respiratory function and one trial reported an adverse effect with prostaglandin E2 analogue misoprostol. No trials have been identified assessing the effectiveness of these agents in improving quality of life, the complications of increased gastric acidity, or survival.

AUTHORS' CONCLUSIONS

Trials have shown limited evidence that agents that reduce gastric acidity are associated with improvement in gastro-intestinal symptoms and fat absorption. Currently, there is insufficient evidence to indicate whether there is an improvement in nutritional status, lung function, quality of life, or survival. Furthermore, due to the unclear risks of bias in the included trials, we are unable to make firm conclusions based on the evidence reported therein. We therefore recommend that large, multicentre, randomised controlled clinical trials are undertaken to evaluate these interventions.

Pancreatic Enzyme Replacement Therapy and Coefficient of Fat Absorption in Children and Adolescents With Cystic Fibrosis

OBJECTIVES

Pancreatic enzyme replacement therapy (PERT) is the proven therapy to substantially reduce fat malabsorption in patients with cystic fibrosis (CF). Few details of the daily practice regarding PERT and the resulting coefficient of fat absorption (CFA) are known. We therefore recorded the PERT and CFA in a large cohort of pancreatic insufficient pediatric patients with CF.

METHODS

We retrospectively studied 1719 completed 3-day dietary food records, including the pancreatic enzyme intake registrations, and 1373 CFA assessments of 224 patients with CF, ages 0-17 years. The clinical characteristics, PERT, expressed as an intake of lipase unit (LU) per gram of fat per day and LU per kilogram per day, and the CFA were described for the group as a whole and separately for those on enteral tube feeding. Cross-sectional relationship between the CFA and the LU per gram of fat per day and LU per kilogram per day were determined for each year of age. We also addressed the effect of the interventions done in patients with CFA outcomes <85%.

RESULTS

The LU per gram of fat per day was relatively stable throughout the age groups, whereas the LU per kilogram per day fell markedly with age. The median CFA in the age group 17 varied between 86% and 91%, however, with a CFA below 85% in 325 of 1373 (24%) of the measurements. No relationship was found between PERT and CFA. The patients with persistent CFA less than 85% had significant lower z scores weight for age and weight for height (P = 0.01) than those with CFA at least 85%.

CONCLUSIONS

In this study population, no correlation between an enzyme dosage and the degree of fat malabsorption was found; however, a CFA below 85% was found in 24% of the measurements.

Drug therapies for reducing gastric acidity in people with cystic fibrosis

BACKGROUND

Malabsorption of fat and protein contributes to poor nutritional status in people with cystic fibrosis. Impaired pancreatic function may also result in increased gastric acidity, leading in turn to heartburn, peptic ulcers and the impairment of oral pancreatic enzyme replacement therapy. The administration of gastric acid-reducing agents has been used as an adjunct to pancreatic enzyme therapy to improve absorption of fat and gastro-intestinal symptoms in people with cystic fibrosis. It is important to establish the evidence regarding potential benefits of drugs that reduce gastric acidity in people with cystic fibrosis.

OBJECTIVES

To assess the effect of drug therapies for reducing gastric acidity for: nutritional status; symptoms associated with increased gastric acidity; fat absorption; lung function; quality of life and survival; and to determine if any adverse effects are associated with their use.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals, abstract books and conference proceedings.Most recent search of the Group's Trials Register: 17 March 2014.

SELECTION CRITERIA

All randomised and quasi-randomised trials involving agents that reduce gastric acidity compared to placebo or a comparator treatment.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed trial quality and extracted data.

MAIN RESULTS

The searches identified 39 trials; 17 of these, with 273 participants, were suitable for inclusion, but the number of trials assessing each of the different agents was small. Seven trials were limited to children and four trials enrolled only adults. Meta-analysis was not performed, 14 trials were of a cross-over design and we did not have the appropriate information to conduct comprehensive meta-analyses. The included trials were generally not reported adequately enough to allow judgements on risk of bias.However, one trial found that drug therapies that reduce gastric acidity improved gastro-intestinal symptoms such as abdominal pain; seven trials reported significant improvement in measures of fat malabsorption; and two trials reported no significant improvement in nutritional status. Only one trial reported measures of respiratory function and one trial reported an adverse effect with prostaglandin E2 analogue misoprostol. No trials have been identified assessing the effectiveness of these agents in improving quality of life, the complications of increased gastric acidity, or survival.

AUTHORS' CONCLUSIONS

Trials have shown limited evidence that agents that reduce gastric acidity are associated with improvement in gastro-intestinal symptoms and fat absorption. Currently, there is insufficient evidence to indicate whether there is an improvement in nutritional status, lung function, quality of life, or survival. Furthermore, due to the unclear risks of bias in the included trials, we are unable to make firm conclusions based on the evidence reported therein. We therefore recommend that large, multicentre, randomised controlled clinical trials are undertaken to evaluate these interventions.

An overview of the diagnosis and management of nutrition in chronic pancreatitis

Chronic pancreatitis is characterized by long-standing inflammation of the pancreas, which results in fibrosis and the gradual loss of pancreatic function. The loss of islets and acinar cells results in diabetes and exocrine insufficiency, respectively. Exocrine insufficiency can result in maldigestion of fat, protein, and carbohydrate as well as vitamins and minerals. Patients may present with variable severity of disease, from mild to severe. The diagnosis of chronic pancreatitis can be challenging, especially in patients with early or mild disease who have few to no morphologic abnormalities on standard abdominal imaging studies. A number of imaging modalities and tests have evolved to aid in the diagnosis of chronic pancreatitis based on changes in structure or function. Clinicians typically focus on treating pain in chronic pancreatitis as opposed to exocrine insufficiency, despite the fact that maldigestion and malabsorption can result in nutrition deficiencies. The aims of this review are to describe the various modalities used to diagnose chronic pancreatitis, to illustrate the nutrition deficiencies associated with exocrine insufficiency, and to provide an overview of nutrition assessment and treatment in these patients.

Complicated Clostridium difficile colitis in children with cystic fibrosis: association with gastric acid suppression?

Patients with cystic fibrosis (CF) have several risk factors for Clostridium difficile colonization such as frequent hospitalization and exposure to a broad array of antibiotics utilized for the control, eradication, and prophylaxis of respiratory pathogens. However, despite this high rate of colonization, the occurrence of C. difficile infection (CDI) in CF is rare. We report three children with CF who presented with severe community-associated CDI. All three children had complicated courses and one died. These children were in good health without significant morbidities, and were not frequently hospitalized nor did they receive frequent antibiotic courses. The occurrence of 3 severe cases within a 15-month period prompted us to report these cases and review the literature in regard to CDI. We reviewed the CF GI tract as possible risk factors for a high rate of C. difficile colonization in individuals with CF. Since a high percentage of individuals with CF are on gastric acid blocking agents, we also focused on gastric acid suppression as a potential risk factor for CDI.

Retrospective analysis to investigate the effect of concomitant use of gastric acid-suppressing drugs on the efficacy and safety of pancrelipase/pancreatin (CREON®) in patients with pancreatic exocrine insufficiency

OBJECTIVES

This study aimed to determine whether the efficacy of pancrelipase/pancreatin (CREON®) may be affected by the concomitant use of proton pump inhibitors (PPIs)/histamine-2 receptor antagonists (H2RAs).

METHODS

An analysis of integrated data from all clinical trials of pancrelipase/pancreatin supported by Abbott (34 trials, 1142 unique subjects) was conducted. All trials included patients with pancreatic exocrine insufficiency, and most cases were associated with cystic fibrosis, chronic pancreatitis, or pancreatic surgery. Study designs included single and double blind, open label, parallel group, and crossover, and most were randomized. The primary end point for this analysis was on-treatment coefficient of fat absorption (CFA) according to concomitant PPI/H2RA use (yes/no).

RESULTS

There were no meaningful differences in mean CFA values at the end of pancrelipase/pancreatin treatment by concomitant PPI/H2RA use: yes (n = 254), 82.7% versus no (n = 449), 84.2%. No meaningful differences were observed when the same analysis was carried out by disease type (cystic fibrosis, chronic pancreatitis, and pancreatic surgery).

CONCLUSIONS

This analysis of data from clinical trials enrolling patients with pancreatic exocrine insufficiency suggests that the efficacy of pancrelipase/pancreatin is not affected by concomitant PPI/H2RA use, as determined by end-of-treatment CFA values, and supports the treatment guidelines' recommendation that acid suppression is not routinely required with pancreatic enzyme replacement therapy.

Pubertal height velocity and associations with prepubertal and adult heights in cystic fibrosis

OBJECTIVES

To test the hypothesis that pubertal peak height velocity (PHV) in cystic fibrosis (CF) has improved and is influenced by prepubertal growth and genetic potential.

STUDY DESIGN

PHV from 1862 children born in 1984-87 and documented in the 1986-2008 US CF Foundation Registry was determined by statistical modeling and classified into normal, delayed (2-SD > average age), attenuated (magnitude <5th percentile), or both delayed and attenuated (D&A). Genetic potential for height was estimated by parental stature.

RESULTS

PHV averaged 8.4 cm/year at age 14.0 years in boys and 7.0 cm/year at age 12.1 years in girls, ∼6-month delay and ∼15% reduction compared with healthy children. PHV was normal in 60%, delayed in 9%, attenuated in 21%, and D&A in 5%. Patients with delayed PHV reached similar adult height percentile (boys: 34th, girls: 46th) to those with normal PHV (boys: 33rd, girls: 34th); both were significantly taller than the attenuated (boys: 11th, girls: 19th) and D&A PHV subgroups (boys: 8th, girls: 14th). Pancreatic-sufficient patients had taller prepubertal and adult heights but similar PHV compared with pancreatic-insufficient or meconium ileus patients. Adjusting for genetic potential reduced adult height percentiles more in boys (from 25th to 16th) than girls (from 28th to 24th). Height at age 7 years, PHV age and magnitude, and parental stature significantly predicted adult height.

CONCLUSIONS

Pubertal PHV has improved in children with CF born after mid-1980s compared with older cohorts but remains below normal. Suboptimal prepubertal and pubertal growth led to adult height below genetic potential in CF.

Study design considerations for evaluating the efficacy and safety of pancreatic enzyme replacement therapy in patients with cystic fibrosis

In 2006, the US FDA issued a 'Guidance for Industry' regarding submission of New Drug Applications for pancreatic enzyme replacement therapy (PERT) products. Five oral delayed-release PERT products have been approved by the FDA, and several others are under development and/ or evaluation for New Drug Application submission. We present in this paper recommendations of the Cystic Fibrosis Foundation's Cystic Fibrosis (CF) Therapeutics Development Network and Data Safety Monitoring Board regarding study design considerations for evaluating PERT products in patients with CF. Careful attention to study design and accuracy of the outcome measures has confirmed our understanding of the efficacy and safety of PERT for the treatment of exocrine pancreatic insufficiency of CF.

Coefficients of fat and nitrogen absorption in healthy subjects and individuals with cystic fibrosis

BACKGROUND

We sought to compare the differences of coefficient of fat absorption (CFA) and coefficient of nitrogen absorption (CNA) in healthy individuals and those with cystic fibrosis (CF) and to study the precision of CFA and CNA.

METHODS

Sixteen healthy and 23 subjects with CF and pancreatic insufficiency ate a high-fat, high-protein diet for 72 hours; stool was collected between blue food dye markers to determine CFA and CNA. Subjects with CF withheld pancreatic enzymes. Tests were repeated on 5 of the CF and 10 of the healthy subjects.

RESULTS

In healthy subjects, mean CFA was 93.5% ± 2.7%; mean CNA was 88.1% ± 5%. Median test-retest in 10 healthy subjects was +0.7% CFA (range, -8.1% to + 5.9%) and +0.9% CNA (range, -14.6% to +6.8%). For subjects with CF, mean CFA was 38.5% ± 14.7% and mean CNA was 52.2% ± 11.4%. Median test-retest change in 5 subjects with CF was -6.9% CFA (range, -19.7% to +42.8%) and +14.7% CNA (range, -6.4% to +42.8%).

CONCLUSIONS

CFA and CNA have inconsistent precision in CF. The limitations of CFA as a measure of steatorrhea correction in CF should be recognized in studies of pancreatic enzyme supplements.

Drug therapies for reducing gastric acidity in people with cystic fibrosis

BACKGROUND

Malabsorption of fat and protein contributes to poor nutritional status in people with cystic fibrosis. Impaired pancreatic function may also result in increased gastric acidity, leading in turn to heartburn, peptic ulcers and the impairment of oral pancreatic enzyme replacement therapy. The administration of gastric acid-reducing agents has been used as an adjunct to pancreatic enzyme therapy to improve absorption of fat and gastro-intestinal symptoms in people with cystic fibrosis. It is important to establish the evidence regarding potential benefits of drugs that reduce gastric acidity in people with cystic fibrosis.

OBJECTIVES

To assess the effect of drug therapies for reducing gastric acidity for: nutritional status; symptoms associated with increased gastric acidity; fat absorption; lung function; quality of life and survival; and to determine if any adverse effects are associated with their use.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals, abstract books and conference proceedings.Most recent search of the Group's Trials Register: 15 February 2012.

SELECTION CRITERIA

All randomised and quasi-randomised trials involving agents that reduce gastric acidity compared to placebo or a comparator treatment.

DATA COLLECTION AND ANALYSIS

Both authors independently selected trials, assessed trial quality and extracted data.

MAIN RESULTS

Thirty-eight trials were identified from the searches. Sixteen trials, with 256 participants, were suitable for inclusion. Seven trials were limited to children and three trials enrolled only adults. Meta-analysis was not performed. However, one trial found that drug therapies that reduce gastric acidity improved gastro-intestinal symptoms such as abdominal pain; seven trials reported significant improvement in measures of fat malabsorption; and two trials reported no significant improvement in nutritional status. Only one trial reported measures of respiratory function and one trial reported an adverse effect with prostaglandin E2 analogue misoprostol. No trials have been identified assessing the effectiveness of these agents in improving quality of life, the complications of increased gastric acidity, or survival.

AUTHORS' CONCLUSIONS

Trials have shown limited evidence that agents that reduce gastric acidity are associated with improvement in gastro-intestinal symptoms and fat absorption. Currently, there is insufficient evidence to indicate whether there is an improvement in nutritional status, lung function, quality of life, or survival. We therefore recommend that large, multicentre, randomised controlled clinical trials are undertaken to evaluate these interventions.

Systematic review: efficacy and safety of pancreatic enzyme supplements for exocrine pancreatic insufficiency

BACKGROUND

Pancreatic enzyme supplements are standard therapy for fat malabsorption in patients with exocrine pancreatic insufficiency. The FDA determined that published data are insufficient to support the efficacy and safety of these agents.

AIM

To determine if pancreatic enzyme supplements are: (i) superior to placebo for treating fat malabsorption and (ii) superior to other supplements based on randomized cross-over trials.

METHODS

A computer-assisted search of MEDLINE and EMBASE was performed to identify relevant studies. Data extraction on study design, improvement in coefficient of fat absorption, diarrhoea and adverse events using prespecified forms.

RESULTS

A total of 12 manuscripts met inclusion criteria. Most studies (10/12) compared pancreatic enzyme supplements that used different delivery systems, while using similar quantities of enzymes. These studies found no consistent difference in fat malabsorption or gastrointestinal symptoms between different active treatments. Two small placebo-controlled trials (n = 65 patients) demonstrate that pancreatic enzyme supplements are superior to placebo for fat absorption. Data are inadequate to determine if pancreatic enzyme supplements lead to weight gain or improvement in diarrhoea.

CONCLUSIONS

Based on data from randomized cross-over trials, pancreatic enzyme supplements appear to improve fat malabsorption. No specific branded product or specific delivery system is superior for treatment of fat malabsorption in patients with exocrine pancreatic insufficiency.

Delayed release pancrelipase for treatment of pancreatic exocrine insufficiency associated with chronic pancreatitis

Pancreatic enzyme supplements (PES) are used in chronic pancreatitis (CP) for correction of pancreatic exocrine insufficiency (PEI) as well as pain and malnutrition. The use of porcine pancreatic enzymes for the correction of exocrine insufficiency is governed by the pathophysiology of the disease as well as pharmacologic properties of PES. Variability in bioequivalence of PES has been noted on in vitro and in vivo testing and has been attributed to the differences in enteric coating and the degree of micro-encapsulation. As a step towards standardizing pancreatic enzyme preparations, the Food and Drug Administration now requires the manufacturers of PES to obtain approval of marketed formulations by April 2010. In patients with treatment failure, apart from evaluating drug and dietary interactions and compliance, physicians should keep in mind that patients may benefit from switching to a different formulation. The choice of PES (enteric coated versus non-enteric coated) and the need for acid suppression should be individualized. There is no current standard test for evaluating adequacy of therapy in CP patients and studies have shown that optimization of therapy based on symptoms may be inadequate. Goals of therapy based on overall patient presentation and specific laboratory tests rather than mere correction of steatorrhea are needed.

Systematic review: pancreatic enzyme treatment of malabsorption associated with chronic pancreatitis

BACKGROUND

Pancreatic enzyme supplementation is standard treatment for malabsorption caused by chronic pancreatitis. The FDA recently required all manufacturers to submit New Drug Applications to continue to market these agents because published data demonstrated variation in formulation, bioavailability and shelf-life while providing limited data about efficacy and safety.

AIM

To review systematically the design and results of randomized, parallel-design trials of pancreatic enzyme supplements in chronic pancreatitis patients with steatorrhea.

METHODS

A computer-assisted search of MEDLINE and EMBASE was performed to identify relevant studies. Two authors performed duplicate data extraction on study design, improvement in coefficient of fat absorption (CFA), diarrhoea and adverse events using pre-specified forms. Agreement between investigators for data extraction was greater than 95%.

RESULTS

Of 619 articles found through literature searching, 20 potentially relevant articles were identified and four manuscripts met inclusion criteria. No studies performed head-to-head comparisons of different supplements. Enzyme supplementation is more likely to improve CFA compared with placebo, but fat malabsorption remained abnormal. Important differences in patient population, study endpoint, study design, pancreatic enzyme dosage and measurement of CFA were present across trials, which precluded comparison of different agents.

CONCLUSIONS

Enzyme supplementation improves CFA compared to placebo, but may not abolish steatorrhoea.

Pancreatic enzyme pharmacotherapy

Supplemental pancreatic enzyme preparations are provided to patients with conditions of pancreatic exocrine deficiency such as chronic pancreatitis and cystic fibrosis. These patients frequently experience steatorrhea, which occurs from inadequate fat absorption. The delivery of sufficient enzyme concentrations into the duodenal lumen simultaneously with meals can reduce nutrient malabsorption, improve the symptoms of steatorrhea, and in some cases alleviate the pain associated with chronic pancreatitis. Current clinical practices dictate administration of lipase 25,000-40,000 units/meal by using pH-sensitive pancrelipase microspheres, along with dosage increases, compliance checks, and differential diagnosis in cases of treatment failure. Despite the large number of specialty enzyme replacements available commercially, many patients remain dissatisfied with standard therapy, and future developments are needed to optimize treatment in these individuals.

Choline-related supplements improve abnormal plasma methionine-homocysteine metabolites and glutathione status in children with cystic fibrosis

BACKGROUND

Liver triacylglycerol accumulation and oxidative stress are common in cystic fibrosis (CF) and also occur in choline deficiency. Previously, we showed an association between elevated plasma homocysteine, reduced ratios of S-adenosylmethionine to S-adenosylhomocysteine (SAM:SAH) and of phosphatidylcholine to phosphatidylethanolamine, and phospholipid malabsorption in children with CF.

OBJECTIVE

The objective was to address a possible relation between altered methionine-homocysteine metabolism and choline metabolism in children with CF.

DESIGN

Children with CF were assigned without bias to supplementation with 2 g lecithin/d (n = 13), 2 g choline/d (n = 12), or 3 g betaine/d (n = 10) for 14 d. Plasma concentrations of methionine, adenosine, cysteine, cysteinyl-glycine, glutathione, glutathione disulfide (GSSG), and fatty acids; SAM:SAH; and red blood cell phospholipids were measured within each group of children with CF before and after supplementation. Plasma from healthy children without CF (n = 15) was analyzed to obtain reference data.

RESULTS

Children with CF had higher plasma homocysteine, SAH, and adenosine and lower methionine, SAM:SAH, and glutathione:GSSG than did children without CF. Supplementation with lecithin, choline, or betaine resulted in a significant increase in plasma methionine, SAM, SAM:SAH, and glutathione:GSSG and a decrease in SAH (n = 35). Supplementation with choline or betaine was associated with a significant decrease in plasma SAH and an increase in SAM:SAH, methionine, and glutathione:GSSG. Supplementation with lecithin or choline also increased plasma methionine and SAM.

CONCLUSION

We showed that dietary supplementation with choline-related compounds improves the low SAM:SAH and glutathione redox balance in children with CF.

Evidence of choline depletion and reduced betaine and dimethylglycine with increased homocysteine in plasma of children with cystic fibrosis

Cystic fibrosis (CF) is associated with many clinical complications including steatosis for which the relation to defective CF transmembrane conductance regulator protein is unclear. Choline deficiency results in hepatic steatosis. Choline is the precursor of betaine, which donates methyl groups for remethylation of homocysteine to methionine and dimethylglycine. Previously, we have shown phospholipid malabsorption and increased plasma homocysteine in children with CF. In these studies we used normal phase HPLC with tandem mass spectrometry to determine plasma choline, betaine, and dimethylglycine in children with CF (n = 34) and healthy control children without CF (n = 15). Plasma choline, betaine, and dimethylglycine were significantly lower in children with CF (means +/- SEM, 6.48 +/- 0.35, 23.8 +/- 1.49, 1.49 +/- 0.13 mumol/L, respectively) than in children without CF (8.98 +/- 0.46, 37.3 +/- 1.84, 3.01 +/- 0.17 mumol/L, respectively). Plasma choline (r = 0.373, P = 0.007) and betaine (r = 0.399, P = 0.005) were positively related to methionine, and choline was inversely related to homocysteine (r = -0.316, P = 0.03). Choline, betaine, and dimethylglycine were all significantly and positively related to the plasma S-adenosylmethionine:S-adenosylhomocysteine (SAM:SAH) ratio (r = 0.294, r = 0.377, r = 0.442, respectively; P < 0.05). The plasma choline:betaine and betaine:dimethylglycine ratios did not differ between the children with CF and the control children, suggesting no increase in betaine synthesis, or betaine-dependent remethylation of homocysteine. These studies suggest that choline depletion may contribute to increased homocysteine in children with CF. Choline depletion and altered thiol metabolism may contribute to the clinical complications associated with CF.

Enteric-coated pancreatic enzyme with bicarbonate is equal to standard enteric-coated enzyme in treating malabsorption in cystic fibrosis

OBJECTIVES

To compare the efficacy of an enteric-coated buffered pancreatic enzyme (EC buffered PE) containing 1.5 mEq of bicarbonate per capsule with a conventional enteric-coated enzyme (EC-PE) capsule in cystic fibrosis patients with signs or symptoms of moderate to severe malabsorption.

METHODS

In a double-blind crossover study, subjects were randomly assigned to two consecutive, 2-week phases using an EC buffered PE product and conventional EC-PE product. Seventy-two hour stool collections from each phase were analyzed for energy, fat, and nitrogen content and expressed as percent of estimated intake.

RESULTS

Twenty-one patients with cystic fibrosis and pancreatic insufficiency (14 female, mean age 20.6 +/- 11.5 years, range 8.8-41.9) completed the study. There was no significant difference in percent malabsorption of energy (19.4% vs. 19.0%), fat (20.7% vs. 20.2%), or nitrogen (10.4% vs. 10.7%) between the EC buffered PE product and the conventional EC-PE product. However, patients taking the EC buffered PE product received less enzyme based on actual enzyme activity measured in vitro (3,468 +/- 1,434 U lipase/g fat vs. 3,978 +/- 1,474 U lipase/g fat, P < 0.02).

CONCLUSIONS

In the doses used, nutrient absorption of patients taking EC buffered PE preparation offers no advantage over a conventional EC-PE preparation.

Pharmacokinetics of proton pump inhibitors in children

The use of proton pump inhibitors (PPIs) has become widespread in children and infants for the management of paediatric acid-related disease. Pharmacokinetic profiles of only omeprazole and lansoprazole have been well characterised in children over 2 years of age with acid-related diseases. Few data have been recently published regarding the pharmacokinetics of pantoprazole in children, and none are available for rabeprazole or esomeprazole. The metabolism of PPI enantiomers has never been studied in the paediatric population. A one-compartment model best describes the pharmacokinetic behaviour of omeprazole, lansoprazole and pantoprazole in children, with important interindividual variability for each pharmacokinetic parameter. Like adults, PPIs are rapidly absorbed in children following oral administration; the mean time to reach maximum plasma concentration varies from 1 to 3 hours. Since these agents are acid labile, their oral formulations consist of capsules containing enteric-coated granules. No liquid formulation is available for any of the PPIs. Thus, for those patients unable to swallow capsules, extemporaneous liquid preparations for omeprazole and lansoprazole have been reported; however, neither the absolute nor the relative bioavailabilities of these oral formulations have been studied in children. Intravenous formulations are available for omeprazole (in Europe), lansoprazole and pantoprazole. PPIs are rapidly metabolised in children, with short elimination half-lives of around 1 hour, similar to that reported for adults. All PPIs are extensively metabolised by the liver, primarily by cytochrome P450 (CYP) isoforms CYP2C19 and CYP3A4, to inactive metabolites, with little unchanged drug excreted in the urine. Similar to that seen in adults, the absolute bioavailability of omeprazole increases with repeated dosing in children; this phenomenon is thought to be due to a combination of decreased first-pass elimination and reduced systemic clearance. The apparent clearance (CL/F) of omeprazole, lansoprazole and pantoprazole appears to be faster for children than for adults. A higher metabolic capacity in children as well as differences in the extent of PPI bioavailability are most likely responsible for this finding. This may partly account for the need in children for variable and sometimes considerably greater doses of PPIs, on a per kilogram basis, than for adults to achieve similar plasma concentrations. Furthermore, no studies have been able to demonstrate a statistically significant correlation between age and pharmacokinetic parameters among children. Despite the small number of very young infants studied, there is some evidence for reduced PPI metabolism in newborns. The limited paediatric data regarding the impact of CYP2C19 genetic polymorphism on PPI metabolism are similar to those reported for adults, with poor metabolisers having 6- to 10-fold higher area under the concentration-time curve values compared with extensive metabolisers. Finally, because a pharmacokinetic/pharmacodynamic relationship exists for PPIs, the significant interindividual variability in their disposition may partly explain the wide range of therapeutic doses used in children. Further studies are needed to better define the pharmacokinetics of PPIs in children <2 years of age.

Combining unprotected pancreatic enzymes with pH-sensitive enteric-coated microspheres does not improve nutrient digestion in patients with cystic fibrosis

OBJECTIVES

To assess the efficacy of combining unprotected powder enzymes and oral enteric-coated microsphere (ECM) and to ECM alone in treating nutrient maldigestion in patients with cystic fibrosis.

STUDY DESIGN

Patients were randomly assigned into 2 consecutive, 2-week phases; ECM alone, and ECM plus unprotected powder enzymes. Fecal fat, energy, and nitrogen output were compared with intake at the end of each phase. Two-tailed, paired t tests were performed to compare outcomes.

RESULTS

The mean age of the 14 patients (3 girls) was 5.7 +/- 3.2 years (range, 1.9 to 13.4 years). There was no significant difference in percent malabsorption of fat (15.6% vs 18.2%), energy (13.3% vs 13.4%), or nitrogen (11.8% vs 11.3%) between phases.

CONCLUSIONS

The addition of powder enzymes to ECM did not improve nutrient maldigestion compared with ECM alone.

Phosphatidylcholine and lysophosphatidylcholine excretion is increased in children with cystic fibrosis and is associated with plasma homocysteine, S-adenosylhomocysteine, and S-adenosylmethionine

BACKGROUND

Hepatic steatosis and fat malabsorption are common in cystic fibrosis (CF). Choline deficiency results in decreased phosphatidylcholine synthesis through the cytidine diphosphocholine-choline pathway and hepatic steatosis and in increased synthesis of phosphatidylcholine from phosphatidylethanolamine using methyl groups from S-adenosylmethionine. The intestinal absorption of phosphatidylcholine in CF is unknown.

OBJECTIVES

The objective was to determine whether excretion of choline phosphoglyceride (phosphatidylcholine and lysophosphatidylcholine) is increased in CF and whether loss of fecal choline phosphoglyceride is associated with altered plasma methionine cycle metabolites.

DESIGN

A cross-sectional study involved 53 children with CF and 18 control children without CF. Blood was collected from all participants. A subset of 18 children with CF and 8 control children provided 72-h fecal samples and 5-d food records.

RESULTS

Fat absorption was significantly lower (x+/- SEM: 86.2 +/- 1.6% and 94.1 +/- 1.2%) and excretion of fecal fat (12.9 +/- 1.7 and 3.9 +/- 0.7 g/d), phospholipid (median: 130 and 47.7 mg/d), phosphatidylcholine (19.6 and 2.1 mg/d), and lysophosphatidylcholine (60.3 and 16.9 mg/d) was significantly higher in children with CF than in control children, respectively (P < 0.05). Choline phosphoglyceride excretion was positively correlated with plasma homocysteine and S-adenosylhomocysteine and inversely related with plasma methionine (P < 0.05).

CONCLUSIONS

Choline phosphoglyceride excretion is increased in children with CF and is associated with decreased plasma methionine and increased homocysteine and S-adenosylhomocysteine. These findings suggest choline depletion and an increased choline synthesis by S-adenosylmethionine-dependent methylation in CF, as well as a metabolic link between phosphatidylcholine metabolism and the methionine-homocysteine cycle in humans.

Omeprazole, a proton pump inhibitor, improves residual steatorrhoea in cystic fibrosis patients treated with high dose pancreatic enzymes

Despite treatment with supra-physiological doses of pancreatic enzyme supplements, residual steatorrhoea is a common problem in patients with cystic fibrosis (CF) and pancreatic insufficiency. Strategies to enhance the activity of pancreatic enzymes include decreasing duodenal acidity. The aim of this study was to evaluate the effect of omeprazole (Losec), a proton-pump inhibitor, on fat absorption in CF patients with residual steatorrhoea despite high dose pancreatic enzyme supplements (> or =10,000 U lipase/kg per day). A random cross-over design was chosen. Fat digestion was evaluated with and without omeprazole by means of chemical fat measurements in 3-day stool collections together with 3-day weighed food records for calculation of fat absorption. The results of 15 patients (3 girls and 12 boys) with confirmed steatorrhoea during the control evaluation were analysed. Median age was 8.7 years (range 3.5-15.9 years). Median daily lipase intake was 13,500 U/kg per day (range 10,000-22,000 U/kg per day). During treatment with omeprazole, median faecal fat loss (g fat/day) decreased from 13 g (quartiles 11.5-16.5 g/day) to 5.5 g (quartiles 4.9-8.1 g/day) (P<0.01). The same improvement was noted when fat absorption was calculated: 87% (quartiles 81-89%) without versus 94% (quartiles 90-96%) with omeprazole (P<0.001).

CONCLUSION

Omeprazole improves fat digestion and absorption in cystic fibrosis patients with residual faecal fat loss despite maximal pancreatic enzyme substitution.

Drug therapies for reducing gastric acidity in people with cystic fibrosis

BACKGROUND

Malabsorption of fat and protein contributes to the poor nutritional status in people with cystic fibrosis. Impaired pancreatic function may also result in increased gastric acidity leading in turn to heartburn, peptic ulcers and the impairment of oral pancreatic replacement therapy. The administration of gastric reducing agents has been used as an adjunct to pancreatic enzyme therapy to improve nutritional status, fat malabsorption and gastro-intestinal symptoms in people with cystic fibrosis. It is thus important to establish the current level of evidence regarding potential benefits of drug therapies that reduce gastric acidity in people with cystic fibrosis.

OBJECTIVES

To assess the effect of drug therapies for reducing gastric acidity: in improving nutritional status; on symptoms associated with increased gastric acidity; fat absorption; lung function; quality of life and survival; and to determine if any adverse effects are associated with their use.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group trials register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books and conference proceedings. Most recent search of the Group's register: April 2002.

SELECTION CRITERIA

All randomised and quasi-randomised trials involving agents that reduce gastric acidity compared to placebo or a comparator treatment.

DATA COLLECTION AND ANALYSIS

Both reviewers independently selected trials and assessed trial quality.

MAIN RESULTS

Thirty-six trials were identified from the initial search. Eleven trials with 172 participants were suitable for inclusion. Five trials were limited to children and three trials enrolled only adults. One trial found that drug therapies which reduce gastric acidity improve gastro-intestinal symptoms such as abdominal pain. Five trials reported significant improvement in measures of fat malabsorption. Two trials reported no significant improvement in nutritional status. Only one trial reported measures of respiratory function and one trial reported an adverse effect with prostaglandin E2 analogue misoprostol. No trials have been identified which assess the effectiveness of agents that reduce gastric acidity in improving quality of life, the complications of increased gastric acidity, or survival.

REVIEWER'S CONCLUSIONS

Trials have shown limited evidence that the agents which reduce gastric acidity in people with cystic fibrosis are associated with improvement in gastro-intestinal symptoms and fat absorption. Currently, there is insufficient evidence to indicate whether there is an improvement in nutritional status, lung function, quality of life, or survival. We therefore recommend large, multicentre, randomised controlled clinical trials are undertaken to evaluate these interventions.