Palliation of pain in chronic pancreatitis. Use of enzymes

Management of pain in chronic pancreatitis with emphasis on exogenous pancreatic enzymes

One of the most challenging issues arising in patients with chronic pancreatitis is the management of abdominal pain. Many competing theories exist to explain pancreatic pain including ductal hypertension from strictures and stones, increased interstitial pressure from glandular fibrosis, pancreatic neuritis, and ischemia. This clinical problem is superimposed on a background of reduced enzyme secretion and altered feedback mechanisms. Throughout history, investigators have used these theories to devise methods to combat chronic pancreatic pain including: Lifestyle measures, antioxidants, analgesics, administration of exogenous pancreatic enzymes, endoscopic drainage procedures, and surgical drainage and resection procedures. While the value of each modality has been debated over the years, pancreatic enzyme therapy remains a viable option. Enzyme therapy restores active enzymes to the small bowel and targets the altered feedback mechanism that lead to increased pancreatic ductal and tissue pressures, ischemia, and pain. Here, we review the mechanisms and treatments for chronic pancreatic pain with a specific focus on pancreatic enzyme replacement therapy. We also discuss different approaches to overcoming a lack of clinical response update ideas for studies needed to improve the clinical use of pancreatic enzymes to ameliorate pancreatic pain.

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.

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.

Diagnosis and management of chronic pancreatitis

Chronic pancreatitis represents a condition that is challenging for clinicians secondary to the difficulty in making an accurate diagnosis and the less than satisfactory means of managing chronic pain. This review emphasises the various manifestations that patients with chronic pancreatitis may have and describes recent advances in medical and surgical therapy. It is probable that many patients with chronic abdominal pain are suffering from chronic pancreatitis that is not appreciated. As the pathophysiology of this disorder is better understood it is probable that the treatment will be more successful.

[Therapy of chronic pancreatitis]

Treatment of chronic pancreatitis is dependend on the stage of the disease and its complications. Pain therapy should be based on the knowledge of various causes of pain. In therapy of complications such as bile duct or pancreatic duct strictures interventional endoscopy is usually the first choice followed by surgery. Exocrine insufficiency is treated by porcine pancreatic extracts, endocrine insufficiency by insulin. One has to apply various imaging procedures such as sonography, MRCP, ERCP, endosonography, CT for exact diagnosis of complications and planning various therapeutic strategies. Pseudocysts may be drained via the transgastric, transduodenal, transpapillary or transcutaneous route. Distal prepapillary stenosis of the main pancreatic duct and bile duct stenoses can be drained by stents. Pancreatic duct stones can be desintegrated by shock waves and removed by endoscopy. Early diagnosis of pancreatic carcinoma as a potential complication of long standing inflammation of the pancreas remains an unsolved problem.

Medical therapy for chronic pancreatitis pain

Chronic pancreatitis should be considered in all patients with unexplained abdominal pain. Management of abdominal pain in these patients continues to pose a formidable challenge. The importance of small duct disease without radiographic abnormalities is now a well-established concept. It is meaningful to determine whether patients with chronic pancreatitis have small duct or large duct disease because this distinction has therapeutic implications. Diagnostic evaluation should begin with simple noninvasive and inexpensive tests like serum trypsinogen and fecal elastase, to be followed where appropriate by more complicated measures such as the secretin hormone stimulation test, especially in patients with suspected small duct disease. No universal causal treatment is available. Non-enteric-coated enzyme preparations are useful for treatment of pain, whereas enteric-coated enzyme preparations are preferred for steatorrhea. Octreotide is used increasingly for abdominal pain that is unresponsive to pancreatic enzyme therapy. When medical therapy for chronic pancreatitis pain has failed, endoscopic therapy, endoscopic ultrasound-guided celiac plexus block, and thoracoscopic splanchnicectomy, performed by experts, may be considered for a highly selected patient population. Surgical ductal decompression is appropriate in patients with considerable pancreatic ductal dilation. The role and efficacy of cholecystokinin-receptor antagonists, antioxidants, and antidepressant drugs remain to be defined.

Involvement of cholecystokinin/gastrin-related peptides and their receptors in clinical gastrointestinal disorders

In this paper the possible roles of cholecystokinin (CCK), gastrin, or gastrin-related peptides and their receptors in human gastrointestinal diseases are reviewed. For CCK/CCK(A) receptors (CCK(A)-R), the evidence for their proposed involvement in diseases caused by impaired CCK release or CCK(A)-R mutations, pancreatic disorders (acute/chronic pancreatitis), gastrointestinal motility disorders (gallbladder disease, irritable bowel syndrome), pancreatic tumor growth and satiety disorders, is briefly reviewed. The evidence that has established the involvement of gastrin/CCK(B)-R in mediating the action of hypergastrinaemic disorders, mediating hypergastrinaemic effects on the gastric mucosa (ECL hyperplasia, carcinoids, parietal cell mass), and acid-peptic diseases, is reviewed. The evidence for their possible involvement in mediating growth of gastric and pancreatic tumours and possible involvement of gastrin-related peptides in colon cancers, is reviewed briefly.