Systematic review: the use of mesalazine in inflammatory bowel disease

Mesalazine granules are superior to Eudragit-L-coated mesalazine tablets for induction of remission in distal ulcerative colitis - a pooled analysis

BACKGROUND

Different oral formulations of 'mesalazine (mesalamine)' may have different efficacy in distal ulcerative colitis.

AIM

To evaluate the efficacy of mesalazine granules (Salofalk granules) vs. mesalazine tablets (Salofalk tablets) as induction therapy in patients with distinct extensions of ulcerative colitis.

METHODS

A pooled analysis of 705 patients from four prospective, randomised, double-blind phase III trials was performed. The efficacy of 8 weeks' induction with 3 g/day mesalazine granules [3 g once daily (o.d.) or 1 g three times daily (t.d.s)] vs. 3 g/day mesalazine tablets (1 g t.d.s.) was compared in terms of clinical remission (CR: CAI ≤ 4) and endoscopic remission (ER: EI ≤ 3) (both according to Rachmilewitz) in subgroups with pancolitis, left-sided colitis, or proctosigmoiditis.

RESULTS

Mesalazine granules were equipotent to mesalazine tablets in pancolitis regarding CR (72% vs. 71%, P = 0.909) and ER (58% vs. 49%, P = 0.338). In left-sided colitis, both mesalazine formulations were equipotent regarding CR (66% vs. 67%; P = 0.843) but mesalazine granules were superior regarding ER (56% vs. 37%; P = 0.025). In proctosigmoiditis, mesalazine granules were significantly more effective than mesalazine tablets regarding CR (78% vs. 55% P < 0.001) and ER (67% vs. 43% P < 0.001). Furthermore, o.d. application of mesalazine granules was more effective than t.d.s. dosing in left-sided colitis (CR 73% vs. 62%, P = 0.181; ER 71% vs. 48% P = 0.005) and proctosigmoiditis (CR 86% vs. 73%, P = 0.020; ER 75% vs. 61%, P = 0.021), but not in pancolitis.

CONCLUSION

This pooled analysis supports the hypothesis that mesalazine granules are superior to mesalazine tablets in induction of remission in distal colitis and should be taken once daily.

Common misconceptions about 5-aminosalicylates and thiopurines in inflammatory bowel disease

Misconceptions are common in the care of patients with inflammatory bowel disease (IBD). In this paper, we state the most commonly found misconceptions in clinical practice and deal with the use of 5-aminosalicylates and thiopurines, to review the related scientific evidence, and make appropriate recommendations. Prevention of errors needs knowledge to avoid making such errors through ignorance. However, the amount of knowledge is increasing so quickly that one new danger is an overabundance of information. IBD is a model of a very complex disease and our goal with this review is to summarize the key evidence for the most common daily clinical problems. With regard to the use of 5-aminosalicylates, the best practice may to be consider abandoning the use of these drugs in patients with small bowel Crohn’ s disease. The combined approach with oral plus topical 5-aminosalicylates should be the first-line therapy in patients with active ulcerative colitis; once-daily treatment should be offered as a first choice regimen due to its better compliance and higher efficacy. With regard to thiopurines, they seem to be as effective in ulcerative colitis as in Crohn’ s disease. Underdosing of thiopurines is a form of undertreatment. Thiopurines should probably be continued indefinitely because their withdrawal is associated with a high risk of relapse. Mercaptopurine is a safe alternative in patients with digestive intolerance or hepatotoxicity due to azathioprine. Finally, thiopurine methyltransferase (TPMT) screening cannot substitute for regular monitoring because the majority of cases of myelotoxicity are not TPMT-related.

Randomised clinical trial: a comparative dose-finding study of three arms of dual release mesalazine for maintaining remission in ulcerative colitis

BACKGROUND

Comparative data regarding different regimens of oral mesalazine (mesalamine) for maintaining remission in ulcerative colitis are limited.

AIM

To evaluate whether 3.0 g mesalazine once-daily (OD) is superior to the standard treatment of 0.5 g mesalazine three times daily (t.d.s.) and to prove the therapeutic equivalence of OD vs. t.d.s. dosing of total 1.5 g mesalazine for remission maintenance in patients with ulcerative colitis.

METHODS

A 1-year, multicentre, double-blind, double-dummy study was undertaken in patients with endoscopically and histologically confirmed ulcerative colitis in remission. Patients were randomised to oral mesalazine 3.0 g OD, 1.5 g OD or 0.5 g t.d.s. The primary efficacy endpoint was the proportion of patients still in clinical remission at the final visit, with clinical relapse being defined as CAI score >4 and an increase of ≥3 from baseline.

RESULTS

The primary efficacy endpoint occurred in 162/217 3.0 g OD patients (75%), 129/212 1.5 g OD patients (61%) and 150/218 0.5 g t.d.s. patients (69%) in the intention-to-treat population, and in 152/177 (86%), 121/182 (67%) and 144/185 (78%) in the per protocol population respectively; 3.0 g OD was superior to both low-dose regimens for the primary endpoint (i.e. P < 0.001, 3.0 g OD vs. 1.5 g OD; P = 0.024, 3.0 g OD vs. 0.5 g t.d.s.; superiority test, per protocol population). Safety analysis, including comprehensive renal monitoring, revealed no concern in any treatment group.

CONCLUSION

Mesalazine 3.0 g once daily was the most effective dose for maintenance of remission in ulcerative colitis of the three regimens assessed, with no penalty in terms of safety.

Amelioration of dextran sulfate sodium-induced chronic colitis by sulfasalazine salicylazosulfapyridine via reducing NF-kappaB transcription factor p65 recruitment to ICAM-1 gene promoters

Sulfasalazine salicylazosulfapyridine (SASP), consisting of 5-aminosalicylic acid bound to sulfapyridine by a diazo bond, is an effective drug in the treatment of inflammatory bowel diseases (IBD). However, its mechanism of action remains a matter of debate. The objective of our work was to investigate SASP's effect on NF-kappaB signal transduction pathway in transcriptional regulation level. Repeated colitis was induced by administration of 4 cycles of 4% dextran sulfate sodium (DSS); The severity of colitis was assessed on the basis of clinical signs, colon length, and histology scores. Moreover, sIgA and haptoglobin (HP) were analyzed by enzyme linked immunosorbent assay, and ICAM-1 gene expression was analyzed by quantitative reverse transcriptase real-time polymerase chain reaction (qRT-PCR) using SYBA green I. NF-kappaB signal transduction proteins and transcriptional factor p65 interaction with promoter of ICAM-1 were assessed by western blotting and chromatin immunoprecipitation assay. SASP administration significantly attenuated the colitis signs and caused substantial reductions of HP expression, and maintained the level of cecum sIgA. SASP inhibited ICAM-1 gene expression and had no effect on MIF gene expression. Also, SASP was able to reduce p-IkBalpha protein expression; however, no change in the activation of IKKalpha, IKKbeta, p65, and IKBalpha was noted. SASP inhibited p65 recruitment to the gene ICAM-1 promoter. In conclusion, inhibition of NF-kappaB pathway signal proteins and blockade of p65 binding to gene ICAM-1 promoter might explain the effect and mechanisms of SASP at alleviating DSS-induced colitis in mice.

Adherence of gastroenterologists to European Crohn's and Colitis Organisation consensus on ulcerative colitis: a real-life survey in Spain

BACKGROUND & AIMS

A European consensus on the management of ulcerative colitis (UC) was recently published; however, there is no adequate evidence about adherence to such guidelines among gastroenterologists. This knowledge would allow the local evaluation of the situation and the adoption of actions to reduce the existent clinical variability.

METHODS

A cross-sectional survey was conducted in Spain to assess the adherence to the European Crohn's and Colitis Organisation (ECCO) guidelines on mild to moderate UC. We surveyed 700 gastroenterologists, and finally a total of 530 gastroenterologists specialised in inflammatory bowel disease (GSIBDs) and general gastroenterologists (GGs), responded to the survey (76%).

RESULTS

Agreement with the guidelines was high; discrepancies included that only 25% of the GGs used the combination of oral and topical 5-aminosalycilic acid (5-ASA) for treating extensive UC vs 45% of the GISBDs. In addition, topical rectal steroids were considered as effective as topical mesalazine by 48% of the GGs vs 31% of the GSIBDs, indefinite treatment with 5-ASA was prescribed by only 26% of the GGs vs 41% of the GSIBDs, and the once daily dosing of 5-ASA was generally used by 46% of the GGs vs 51% of the GSIBDs.

CONCLUSIONS

The questionnaire showed a high degree of agreement between GGs and GSIBDs. Nevertheless, the GSIBD group showed closer agreement with the ECCO guidelines. Furthermore, some shortcomings were found in the GG group, in which increased maintenance treatment with 5-ASA, the use of a single daily dose of 5-ASA, and the use of combined oral and topical treatment for distal colitis should be advised.

Telephone nurse counseling for medication adherence in ulcerative colitis: a preliminary study

OBJECTIVE

Adherence is challenging in episodic chronic conditions that require medication during both symptomatic and quiescent periods, such as ulcerative colitis (UC). Adherence for these conditions is under-studied. This study was a preliminary test of telephone nurse counseling to address cognitive and emotional barriers to adherence in UC.

METHODS

524 people taking mesalamine for UC were referred by their health care providers, and 278 (53%) enrolled. There were no demographic differences between program participants and nonparticipants. Participants reported multiple comorbidities and concomitant medications. All participants received telephone follow-up (M = 2.1 calls) from a registered nurse who used cognitive-behavioral and motivational interviewing counseling techniques. Adherence measured by structured interview was compared to a population baseline using a binomial test.

RESULTS

Attrition was 51% over 6 months but was unrelated to adherence. Participants had better adherence than the expected population rate, with a significant dose-response effect. Reasons for nonadherence were primarily psychological or efficacy-related.

CONCLUSION

Adherence following intervention was better than typical mesalamine adherence. Self-efficacy predicted adherence, but demographic and clinical variables did not. Adherent participants reported more adverse events.

PRACTICE IMPLICATIONS

Attention to patients' cognitive and emotional reactions may help to improve adherence in episodic chronic diseases such as UC.

Oral beclomethasone dipropionate as an alternative to systemic steroids in mild to moderate ulcerative colitis not responding to aminosalicylates

BACKGROUND

Aminosalicylates (5-ASA) are first-line treatment for mild-moderate ulcerative colitis (UC). Systemic corticosteroids (CS) are considered for patients in whom 5-ASA has been unsuccessful, but their use is limited by adverse effects. Beclomethasone dipropionate (BDP), a topically acting steroid with low systemic bioavailability, has a more favorable safety profile, but its role in clinical practice is not yet well established.

AIM

The aim of the present study is to assess whether oral BDP can be an alternative treatment to systemic CS for patients with mild-moderate UC not responding to first-line therapy with 5-ASA.

METHODS

From 2003 to 2006, all consecutive patients with mild-moderate UC unresponsive to oral and topical 5-ASA (+/-topical CS) administered for at least 3 weeks received an 8-week course of oral BDP (10 mg/day for 4 weeks and 5 mg/day for an additional 4 weeks). Co-primary end-points were: (1) clinical remission within 8 weeks, without need of systemic CS; (2) steroid-free remission for 12 months.

RESULTS

Sixty-four patients were included. In this study, within 8 weeks, 48/64 patients (75%) entered remission without systemic CS, while 16/64 (25%) failed to enter remission. Within 12 months, 37/64 patients (58%) had prolonged steroid-free remission, while 11/64 (17%) relapsed. During 1 year, 75% of patients receiving oral BDP could avoid systemic CS.

CONCLUSIONS

Oral BDP can avoid the use of systemic CS in the vast majority of patients with mild-moderate UC not responding to 5-ASA and could be considered as a second-line treatment for these patients.

Mesalamine protects against colorectal cancer in inflammatory bowel disease

BACKGROUND

Individuals with inflammatory bowel disease (IBD) are at increased risk of developing colorectal cancer (CRC) compared with the general population. Previous studies show this risk is strongly associated with dysplasia, extent of disease, duration of disease, and degree of inflammation, while chemoprevention of CRC has less support.

AIM

Evaluate factors influencing risk of colorectal cancer development in inflammatory bowel disease patients.

METHODS

IBD patients with CRC were matched to controls by IBD type, age at diagnosis, sex, race, extent of disease, and disease duration. We compared body mass index, family history of IBD, family history of CRC, tobacco use, and cumulative and daily use of aminosalicylates, immunomodulators, folic acid, steroids, and nonsteroidal anti-inflammatory drugs. Statistical analysis was performed with logistic regression and receiver operating characteristic (ROC) curves.

RESULTS

Of 1,594 IBD patients, 30 CRC patients were identified. Of these, 18 CRC patients were matched to 30 controls. More control patients used a cumulative aminosalicylate dose of >or=4,500 g (46.6% versus 5.6%; P = 0.047), folic acid (40.0% versus 16.7%; P = 0.002), cumulative folic acid dose of >or=1,400 mg (30.0% versus 11.1%; P = 0.014), and average daily folic acid dose of >or=1 mg (30.0% versus 16.7%; P = 0.002) compared with CRC patients. Multivariate analysis showed that a cumulative aminosalicylate dose of >or=4,500 g reduced the risk of CRC by 97.6% (P = 0.047). Folic acid reduced CRC risk by 89% (P = 0.002).

CONCLUSIONS

Aminosalicylate and folic acid use may decrease the risk of CRC among IBD patients.

Update on the role of modified release mesalamine in the management of ulcerative colitis and Crohn's disease

5-aminosalicyclates (5-ASA) remain a key first-line therapy for patients with ulcerative colitis (UC). A range of 5-ASA preparations is available and Eudragit-S^® coated modified release formulations of mesalamine, such as Asacol^®, remain among the most popular choices. We here review the current understanding of the mechanism of action of 5-ASA in inflammatory bowel disease. We evaluate evidence supporting the efficacy and safety of modified release mesalamine for both induction and remission maintenance in UC, including a review of the data from the recent ASCEND studies. We also examine the controversial issue of the role of mesalamine in treatment of Crohn’s disease (CD) and highlight data supporting its use following surgically induced remission of CD. Evidence supporting the use of mesalamine as prophylaxis for colorectal cancer and dysplasia will be considered. Finally, recent developments in our understanding of how to use modified release mesalamine in a safe and cost-effective manner are evaluated, including discussion of the importance of studying patient non-adherence as a key component of future studies in this area.

Effects of mesalamine (5-aminosalicylic acid) on bacterial gene expression

BACKGROUND

5-Aminosalicylic acid (5-ASA) is a well-established treatment for inflammatory bowel disease (IBD) and may reduce the risk of colon cancer in patients with chronic colitis, but the mechanisms underlying these effects have not been fully elucidated. Although 5-ASA delivery is targeted to the distal gut, little is known about its effects on the luminal bacteria that reside there. Intestinal bacteria are believed play a role in causing or perpetuating IBD, and bioremediation has been studied as a therapeutic strategy. In an effort to better understand the bacteriological effects of 5-ASA, we examined the role of this compound at the level of bacterial gene expression.

METHODS

5-ASA was screened for its effects on a random promoter library representing the genome of Salmonella enterica serovar Typhimurium as a model enteric bacterium. Forty-five constructs representing 38 unique promoters were found to be responsive to 5-ASA, and included genes involved in bacterial invasion, cellular metabolism, and stress resistance. Several genes of unknown function were also identified. These effects occurred at 5-ASA concentrations that are relevant to those achieved in the distal intestinal tract in patients with IBD but did not inhibit bacterial growth.

RESULTS

Bacterial invasiveness was decreased by 5-ASA. Some of the identified genes had homologs among commensal Gram-negative enteric bacteria.

CONCLUSIONS

This study demonstrates that 5-ASA has potent effects on bacterial gene expression. These novel findings implicate intestinal bacteria as pharmacological targets of 5-ASA, perhaps contributing to the therapeutic action of this important class of IBD drugs.

Controversies in ulcerative colitis: a survey comparing decision making of experts versus community gastroenterologists

BACKGROUND & AIMS

Despite the development of consensus guidelines in ulcerative colitis (UC), there remain several areas of uncertainty in the everyday management of this incompletely understood disease. We performed a national vignette survey to measure variations in decision-making in areas of controversy.

METHODS

We constructed a survey with 3 vignettes to measure decision-making in 4 areas of controversy in UC: (1) dysplasia management, (2) mesalamine dosing, (3) diagnostic testing for underlying Crohn's disease, and (4) treatment of steroid-refractory inpatient UC. We compared responses between a group of community gastroenterologists and UC experts.

RESULTS

We received 192 responses (36% response). Compared with community gastroenterologists, UC experts were more likely to endorse colectomy for both unifocal and multifocal low-grade dysplasia, use narrow band imaging and chromoendoscopy for surveillance colonoscopy, use high-dose mesalamine for inducing remission, use long-term mesalamine for cancer chemoprevention, order computed tomography enterography to evaluate for Crohn's disease, and to have a lower threshold to call for surgery consultation in steroid-refractory UC. There was little agreement regarding the optimal frequency of surveillance colonoscopy, even among experts. Most respondents favored using infliximab over cyclosporine in steroid-refractory UC.

CONCLUSIONS

Community gastroenterologists and UC experts vary dramatically in their approach to many areas of uncertainty in UC. The only area of consensus between groups is the use of infliximab over cyclosporine in steroid-refractory UC, itself a controversial decision. These data suggest that current practice patterns are highly disparate and focus attention on specific areas of disconnect that should be further investigated.

Ulcerative colitis: current medical therapy and strategies for improving medication adherence

Ulcerative colitis (UC) is chronic inflammation of large intestine and often requires lifelong medication. Medical therapy aims to induce and maintain a clinical remission, reduce the risk of colorectal cancer and improve quality of life. Aminosalicylates are currently the first choice therapy both for the induction and the maintenance of remission in the patients with mild-to-moderate UC. For moderate-to-severe cases or those who do not respond to aminosalicylate therapy, additional treatment options including corticosteroids, immunomodulators, biological agents, cyclosporin, tacrolimus and surgery are available. Poor adherence to medication has been an important barrier to successful management of UC. Nonadherence has been associated with increased relapse rates, higher risk of colorectal cancer, poor quality of life and significantly increased healthcare costs. Therefore, improving adherence to medication is an important approach for a better care of the patients with UC. Definitive strategies are required to help the patients effectively self manage their disease and improve adherence. This review examines current medical therapy for UC, research progresses on medication adherence and the possible strategies for improving adherence in these patients.

Ulcerative proctitis: a review of pharmacotherapy and management

BACKGROUND

Ulcerative proctitis (UP) is a common presentation of ulcerative colitis (UC).

OBJECTIVE

To summarize available literature on up-to-date management and pharmacotherapy of UP patients.

METHODS

Extensive Medline/Embase literature search was performed to identify relevant articles.

RESULTS/CONCLUSION

Topical medication with rectally administered 5-aminosalicylic acid (5-ASA)/corticosteroid suppositories or enemas is effective treatment for most UP patients. Locally administered 5-ASA is more efficacious than oral compounds. The combination of topical 5-ASA and oral 5-ASA or topical steroids should be considered for escalation of treatment. Maintenance treatment is indicated in all UC cases. 5-ASA suppositories are suggested as first-line maintenance therapy if accepted by patients, although oral 5-ASA as maintenance therapy might prevent proximal extension of the disease. After re-assessment, chronically active patients refractory or intolerant to 5-ASAs and corticosteroids may require immunomodulators or biological therapy. Exceptional cases may require a proctocolectomy.

[Medical therapy of inflammatory bowel diseases: ulcerative colitis]

There are fewer significant changes in the medical therapy of ulcerative colitis (UC) compared to Crohn's disease. The most important factors that determine therapy are disease extent and severity. 5-aminosalicylates (5-ASA) constitute the treatment of choice in mild-to-moderate UC. The efficacy of new compounds (e.g. mesalazine) is only mildly improved compared to sulphasalazine; however, their use has become more frequent due to a more favorable side effects profile. Topical medication is more effective in proctitis and distal colitis, and the combination of topical and orally-administered drugs is superior to oral therapy alone also in extensive disease. Thus, this latter regimen should be considered for cases where the escalation of treatment is required. Systemic steroids still represent the first line therapy in acute, severe UC, while in patients who do not respond to steroids, cyclosporine and infliximab should be considered as a second line therapy and as alternatives for colectomy. Maintenance treatment is indicated in all UC cases. 5-ASA compounds are suggested as first line maintenance therapy with the optimal dose still being under investigation. Topical compounds are effective also for maintenance in distal colitis or proctitis, if accepted by the patients. Immunosuppressives, especially azathioprine, should be considered in chronically active, steroid dependent or resistant patients. According to recent publications, azathioprine is almost equally effective in UC and CD. The question of chemoprevention is important during maintenance. There are increasing data supporting the notion that aminosalicylates may lower the risk for UC-associated colorectal cancer. The most important changes in the management of UC are the more frequent use of topical aminosalicylates and azathioprine, the availability of infliximab in severe UC, and increasing use of aminosalicylates for chemoprevention of colorectal carcinoma. Furthermore, adequate attention is needed to better organize the patient-doctor relationship and for greater adherence to medical therapy.

Review article: appropriate use of corticosteroids in Crohn's disease

BACKGROUND

Corticosteroids are a well-established treatment for active Crohn's disease and have been widely used for decades. It has become apparent, however, that a proportion of patients either fails to respond to corticosteroids or is unable to withdraw from them without relapsing. Furthermore, their use is associated with a range of side effects, such that long-term treatment carries unacceptable risk.

AIM

To review the evidence regarding the appropriate use of corticosteroids in Crohn's disease, along with their side effects, safety and alternatives.

METHODS

To collect relevant articles, a PubMed search was performed from 1966 to November 2006 using the terms 'steroid', 'corticosteroid', 'glucocorticoid', 'prednisolone', 'prednisone', 'methylprednisolone', 'hydrocortisone', 'dexamethasone' and 'budesonide' in combination with 'Crohn(s) disease'. Relevant articles were reviewed, as were their reference lists to identify further articles.

RESULTS

When used correctly, corticosteroids are a highly effective, well tolerated, cheap and generally safe treatment for active Crohn' disease. Nevertheless, approximately 50% of recipients will either fail to respond (steroid-resistant) or will be steroid dependent at 1 year. Newer alternatives to corticosteroids are not, however, without risk themselves and, moreover, are not necessarily available universally.

CONCLUSIONS

Steroids are used widely to treat Crohn's disease, a situation that is unlikely to change in the near future. Accordingly, efforts should be made to ensure that they are used correctly and that their side effects are minimized. Reference is made to recently published guidelines and a simplified 'users guide' is presented.

5-Aminosalicylic acid (mesalazine) use in Crohn's disease: a survey of the opinions and practice of Australian gastroenterologists

BACKGROUND

The use of 5-aminosalicylate (5-ASA) drugs in Crohn's disease (CD) is controversial, with their continuing apparent widespread use despite high-level evidence indicating marginal benefit at best and international guidelines recommending limited indications.

METHODS

In order to understand how clinicians translate the evidence base into clinical practice, we surveyed a cross-section of Australian gastroenterologists to determine opinions and prescribing patterns of 5-ASA drugs in CD.

RESULTS

In all, 42% of 285 gastroenterologists who were sent a questionnaire by e-mail responded. Five (4%) never use 5-ASA drugs in CD. The drugs are most commonly prescribed for patients with colonic (96%) or ileocolonic (92%) disease location, inflammatory disease behavior (80%), and mild disease activity (97%). The majority (64%) use a dose of 1-3 g/day, but only 6% use over 4.5 g/day. Less than one-half use 5-ASA drugs as maintenance following surgical resection, but most use it for inducing remission alone (70%) or in combination with other drugs (90%), and continue its use for maintenance. Side effects are thought to be infrequent (62%) or rare (20%) and few common side effects are believed to be serious. Respondents estimated that over 90% of patients were nonadherent to prescribed 5-ASA regimens at least 50% of the time. While 84% believed that 5-ASA drugs were effective in CD, only 58% believed that they were cost-effective.

CONCLUSIONS

In Australia 5-ASA drugs are extensively prescribed for CD at relatively low doses without expectation of patient adherence. Current evidence and guidelines has had little apparent impact on clinical practice. The cost implications are considerable.

A clinical trial on absorption and N-acetylation of oral and rectal mesalazine

BACKGROUND

Mesalazine (5-ASA) is a standard treatment for ulcerative colitis. Extent of absorption and N-acetylation determine systemic exposure to 5-ASA, and are thereby relevant for the safety of the treatment. The aim of the study was to compare absorption and N-acetylation of 5-ASA following rectal or oral drug administration. Healthy subjects were compared to patients with ulcerative colitis to evaluate the impact of chronic inflammation of colorectal mucosa on disposition of 5-ASA.

MATERIALS AND METHODS

First, 12 healthy adults were randomized to receive 2 g of 5-ASA by each of four different formulations: oral delayed release granules, 30 mL enema, 60 mL rectal foam, and 120 mL rectal foam. Second, 12 patients with active ulcerative colitis received 60 mL rectal foam. Pharmacokinetic analysis was performed by determination of 5-ASA and its acetylated, pharmacologically inactive metabolite (Ac-5-ASA) in plasma and urine.

RESULTS

First, systemic exposure to 5-ASA was markedly lower after rectal drug administration as compared to oral dosing (P < 0.001; e.g. median relative bioavailability of 60 mL rectal foam: 36%). Second, N-acetylation of rectal 5-ASA was lower in patients than in healthy subjects [area under the curve (AUC) ratio Ac-5-ASA/5-ASA: 1.6 +/- 0.5 vs. 2.3 +/- 0.4, mean +/- SD, P < 0.01]. High peak plasma concentrations of 5-ASA were correlated with high microscopic disease activity (r = 0.67, P < 0.05).

CONCLUSIONS

Rectal delivery of 5-ASA results in low systemic drug exposure with potentially reduced toxicity in comparison with oral drug administration. Chronic inflammation of colorectal mucosa might be a relevant source of variability in pharmacokinetics of 5-ASA.

Current Medical Therapy for Chronic Inflammatory Bowel Diseases

Chronic idiopathic inflammatory bowel diseases (IBD) include Crohn's disease (CD), ulcerative colitis (UC), and colonic IBD type unclassified (IBDU). This article focuses upon current medical therapies for adult CD and UC, and is organized according to therapy for the corresponding disease type, stage, and severity.

Azathioprine and mesalazine-induced effects on the mucosal flora in patients with IBD colitis

BACKGROUND

The impact of azathioprine and 5-aminosalicylic acid (5-ASA) on the innate immunity and mucosal flora is unknown. The study investigated the influence of IBD treatment on the concentrations and spatial organization of mucosal bacteria using fluorescence in situ hybridization with 16s r-RNA targeting probes.

METHODS

We prospectively investigated colonoscopic biopsies from five groups of 20 subjects each: patients with ulcerative or indeterminate colitis treated with azathioprine (group 1), azathioprine and 5-ASA (group 2), 5-ASA (group 3), untreated IBD (group 4), and healthy controls.

RESULTS

The elevated numbers of leukocytes in mucus of IBD patients were reduced nearly to norm in patients treated with azathioprine alone. In contrast, 5-ASA therapy had no influence on mucus leukocyte migration and was associated with the lowest concentrations of mucosal bacteria of all IBD groups. The suppressed migration of leukocytes in azathioprine-treated patients was accompanied by a 28-fold higher concentration of mucosal bacteria when compared with the 5-ASA group or a 1000-fold increase when compared with healthy controls. The percent of the epithelial surface covered with adherent bacteria (P < 0.001) and the amenability of mucosal bacteria (P = 0.01) were also significantly increased in the azathioprine-treated group compared with all other IBD groups. The patients receiving both 5-ASA and azathioprine did not differ statistically from untreated IBD patients either in mucus leukocyte migration or in bacterial concentrations.

CONCLUSIONS

Azathioprine and 5-ASA induce opposite effects on the mucus barrier. Concomitant therapy of 5-ASA and azathioprine mutually neutralizes the effects of both on the mucosal flora and the barrier function.

Chemoprevention: risk reduction with medical therapy of inflammatory bowel disease

The ideal chemopreventative agent, in addition to being efficacious in the prevention of cancer, must be easily administered, affordable, safe, and well tolerated, with minimal side effects. In the past decade, a growing body of literature has emerged on the prevention of CRC in patients with long-standing CD and UC. The data are not definitive and consist almost exclusively of retrospective case-control and cohort studies rather than the more rigorous prospective RCTs. 5-ASA compounds have been most thoroughly studied, and most of the existing data support the use of 5-ASA in the prevention of CRC. Although the precise dose and duration are unclear, studies suggest that chronic systemic administration of 5-ASA at a dose of at least 1.2 g/d is most likely to be effective. A beneficial effect of folate, albeit not statistically significant, has been consistently shown in every study performed for this purpose. Folate supplementation, which is safe and affordable, should also be recommended for all patients with IBD, especially those taking sulfasalazine. UDCA has been shown to exert a protective effect in most studies on patients with UC and concomitant PSC. Because this patient population is at particularly high risk for CRC, it is advisable to consider UDCA in all patients with colitis complicated by PSC. For patients without PSC, sufficient data do not exist to recommend it for the purpose of cancer prevention. Five of the six corticosteroid studies have found a beneficial effect of systemic steroids, although most did not reach statistical significance. Regardless, given the frequent and serious adverse effects associated with chronic steroid use, systemic corticosteroids should not be prescribed for this indication. Budesonide, an oral corticosteroid with minimal systemic absorption, is a potential alternative, although it has not yet been studied as a chemopreventative agent. Similarly, until the long-term safety of chronic NSAID use can be demonstrated in patients with IBD, the role of NSAIDs in chemoprevention remains undefined. Although the data are conflicting, immune-modulating medications, such as AZA, do not seem to confer any reduction in the risk of dysplasia or CRC. The data on calcium supplementation and statin use are still too limited to endorse their use for the prevention of colitis-related CRC. Chemoprevention is an area that holds great promise in the reduction of morbidity and mortality associated with IBD. Further studies, including prospective trials when possible and cost-effectiveness analyses, need to be performed to develop an optimal strategy for the reduction of cancer risk in patients with IBD.