Oral 5-aminosalicylic acid for maintenance of remission in ulcerative colitis

Progress in research of vedolizumab in treatment of inflammatory bowel disease

Inflammatory bowel disease is a kind of chronic inflammatory disease of the gastrointestinal tract with unclear etiology. At present, its main therapeutic drugs include aminosalicylates, glucocorticoids, immunosuppressive agents, and biological agents. With the deepening study of the disease and the progress of science and technology, there have been more and more studies on the targets for biological agents, including tumor necrosis factor-α, Janus kinase, interleukin, intestinal integrin, etc. As a humanized integrin antagonist, vedolizumab can selectively inhibit the interaction between integrin α4β7 and mucosal addressin cell adhesion molecule-1, and block the migration of lymphocytes to the intestinal tract to alleviate the intestinal inflammation, so as to achieve the therapeutic effect. This article reviews the mechanism, clinical efficacy, and application of vedolizumab in the treatment of inflammatory bowel disease.

The risk factor of clinical relapse in ulcerative colitis patients with low dose 5-aminosalicylic acid as maintenance therapy: A report from the IBD registry

Background

5-Aminosalicylic acids (5-ASA) are effective for ulcerative colitis (UC) as a maintenance therapy. It is not clear when and how to reduce a dose of 5-ASA after inducing remission. We aimed to investigate the clinical characteristics and evaluate the risk factors of relapse for UC patients receiving 5-ASA.

Methods

The medical records of prospectively registered UC patients who received oral 5-ASA as maintenance therapy between January and December 31, 2014, were investigated. The patients’ clinical characteristics in a 2-year follow-up were compared between a relapse group and a remission group.

Results

Of 527 UC patients receiving only oral 5-ASA, 390 (74.0%) maintained remission and 137 (26.0%) relapsed during the follow-up period. Multivariable analysis indicated that a shorter duration of disease remission (p < 0.001, OR: 1.24, 95% CI: 1.12–1.38) was statistically significant for each comparison between the remission and relapse groups among all the patients. Risk factors for clinical relapse were a shorter duration of disease remission (p <0.001, OR: 1.17, 95% CI: 1.04–1.33) in the high-dose 5-ASA group and a shorter duration of disease remission (p = 0.003, OR: 1.45, 95% CI: 1.13–1.89) and a history of steroid use (p = 0.048, OR: 4.73, 95% CI: 1.01–22.2) in the low-dose group.

Conclusions

A dose reduction of 5-ASA might be cautiously selected in UC patients with a history of steroid use and a shorter duration of disease remission.

Rate and Predictors of Mucosal Healing in Ulcerative Colitis Treated with Thiopurines: Results of a Multicentric Cohort Study

BACKGROUND AND AIMS

Mucosal healing (MH) with thiopurines has been poorly investigated in ulcerative colitis (UC). We aimed to assess MH rate in UC patients treated with thiopurine monotherapy.

PATIENTS AND METHODS

We retrospectively collected all UC patients treated with thiopurines more than 6 months who have undergone colonoscopy at baseline and after at least 6 months of treatment. Patients were recruited from January 2005 to May 2015 through a personal database and/or standardized hospital inpatient diagnostic dataset. Patients were excluded in case of any use of other immunomodulator or biological agent. MH was defined as a Mayo endoscopic subscore ≤1 and UCEIS ≤ 2. Histological healing (HH) was defined by the absence of epithelial polynuclear infiltrate, cryptic abscesses, or ulcerations.

RESULTS

Eighty patients (31 women, median age 43 [IQR 32-58]) were included. Median disease duration was 10.5 [6-16] years. At baseline, median full Mayo score, endoscopic subscore, and UCEIS were 8 [6.8-10], 3 [2-3], and 5 [3-6], respectively. MH was first assessed after a mean follow-up of 38 ± 31 months. Median full Mayo score, endoscopic subscore, and UCEIS decreased to 3.5 [1-6], 2 [0-2.2], and 2 [0-4], respectively. MH was achieved in 43.7%, HH in 38%. In multivariate analysis, predictors of MH were thiopurine exposure duration ≥2 years [odds ratio (OR) 2.9, CI 95% (1.1-7.6), p = 0.03] and a prior acute severe colitis [OR 5.9, CI 95% (1.1-32), p = 0.04]. Factors associated with MH during treatment were partial Mayo score ≤2 (NPV = 100%), BMI ≥ 25 kg/m² (NPV = 75%), and MCV ≥ 95 fL (NPV = 73%).

CONCLUSIONS

In UC, thiopurine monotherapy is associated with MH in 43.7% and HH in 38%.

Mesalazine preparations for the treatment of ulcerative colitis: Are all created equal?

Oral mesalazine (also known as mesalamine) is a 5-aminosalicylic acid compound used in the treatment of mild to moderate ulcerative colitis, with high rates of efficacy in induction and maintenance of remission. The therapeutic effect of mesalazine occurs topically at the site of diseased colonic mucosa. A myriad of oral mesalazine preparations have been formulated with various drug delivery methods to minimize systemic absorption and maximise drug availability at the inflamed colonic epithelium. It remains unclear whether different oral mesalazine formulations are bioequivalent. This review aims to evaluate the differences between mesalazine formulations based on the currently available literature and explore factors which may influence the selection of one agent above another.

Thiopurine metabolites variations during co-treatment with aminosalicylates for inflammatory bowel disease: Effect of N-acetyl transferase polymorphisms

AIM: To evaluate variation of the concentration of thiopurine metabolites after 5-aminosalicylate (5-ASA) interruption and the role of genetic polymorphisms of N-acetyl transferase (NAT) 1 and 2.

METHODS: Concentrations of thioguanine nucleotides (TGN) and methymercaptopurine nucleotides (MMPN), metabolites of thiopurines, were measured by high performance liquid chromatography in 12 young patients (3 females and 9 males, median age 16 years) with inflammatory bowel disease (6 Crohn’s disease and 6 ulcerative colitis) treated with thiopurines (7 mercaptopurine and 5 azathioprine) and 5-ASA. Blood samples were collected one month before and one month after the interruption of 5-ASA. DNA was extracted and genotyping of NAT1, NAT2, inosine triphosphate pyrophosphatase (ITPA) and thiopurine methyl transferase (TPMT) genes was performed using PCR assays.

RESULTS: Median TGN concentration before 5-ASA interruption was 270 pmol/8 x 10⁸ erythrocytes (range: 145-750); after the interruption of the aminosalicylate, a 35% reduction in TGN mean concentrations (absolute mean reduction 109 pmol/8 × 10⁸ erythrocytes) was observed (median 221 pmol/8 × 10⁸ erythrocytes, range: 96-427, P value linear mixed effects model 0.0011). Demographic and clinical covariates were not related to thiopurine metabolites concentrations. All patients were wild-type for the most relevant ITPA and TPMT variants. For NAT1 genotyping, 7 subjects presented an allele combination corresponding to fast enzymatic activity and 5 to slow activity. NAT1 genotypes corresponding to fast enzymatic activity were associated with reduced TGN concentration (P value linear mixed effects model 0.033), putatively because of increased 5-ASA inactivation and consequent reduced inhibition of thiopurine metabolism. The effect of NAT1 status on TGN seems to be persistent even after one month since the interruption of the aminosalicylate. No effect of NAT1 genotypes was shown on MMPN concentrations. NAT2 genotyping revealed that 6 patients presented a genotype corresponding to fast enzymatic activity and 6 to slow activity; NAT2 genotypes were not related to thiopurine metabolites concentration in this study.

CONCLUSION: NAT1 genotype affects TGN levels in patients treated with thiopurines and aminosalicylates and could therefore influence the toxicity and efficacy of these drugs; however the number of patients evaluated is limited and this has to be considered a pilot study.

A novel stimuli-synchronized alloy-treated matrix for space-defined gastrointestinal delivery of mesalamine in the Large White pig model

The study focussed on designing a Stimuli-Synchronized Matrix (SSM) for space-defined colonic delivery of the anti-inflammatory drug mesalamine. The configured matrix provided time-independent delivery and stimuli targeting. Formulations were optimized according to a Box-Behnken experimental design that constituted mesalamine-loaded BaSO4-crosslinked chitosan dispersed within a pectin, carboxymethylcellulose and xanthan gum complex. The complex was compressed into matrices and subsequently alloy-treated with pectin and ethylcellulose. In vitro drug release was determined in the presence and absence of colonic enzymes and the mean dissolution time was used for formulation optimization. To mechanistically elucidate the synchronous catalytic action of the enzymes pectinase and glucosidase on the matrix, computer-aided 3D modelling of active fractions of the enzyme-substrate complexes was generated to predict the orientation of residues affecting the substrate domain. Drug release profiles revealed distinct colonic enzyme responsiveness with fractions of 0.402 and 0.152 of mesalamine released in the presence and absence of enzymes, respectively after 24h. The commercial comparator product showed irreproducible release profiles over the same period (SD=0.550) compared to the SSM formulation (SD=0.037). FTIR spectra of alloy-treated matrices showed no peaks from 1589 to 1512cm(-1) after colonic enzyme exposure. With increasing enzyme exposure there were also no peaks between 1646 and 1132cm(-1). This indicated polymeric enzyme cleavage for controlled and space-defined release of mesalamine. Plasma concentration profiles in the Large White pig model produced a Cmax of 3.77±1.375μg/mL compared to 10.604±2.846μg/mL for the comparator formulation. The SSM formulation proved superior over the comparator product by providing superiorly controlled enzyme-responsive colonic drug delivery.

Optimizing clinical use of mesalazine (5-aminosalicylic acid) in inflammatory bowel disease

Mesalazine [5-aminosalicylic acid (5-ASA)] has been used for over 30 years in the treatment of inflammatory bowel disease (IBD). It is a highly effective, safe, and well-tolerated drug for treatment of mild to moderate ulcerative colitis, which represents most patients with this disease. Recent studies of patient adherence to 5-ASA therapies in ulcerative colitis have highlighted the need for regimens that enable long-term compliance to significantly reduce the risk of troublesome and debilitating flares in the short term, and possibly colon cancer in the long term. Indeed, much of the recent innovation in clinical use of 5-ASA in colitis has come from studies of novel delivery mechanisms and simplified oral dosing schedules. These studies have provided much needed clarity on essential matters such as starting dose, dose escalation, and efficacy in terms of the ideal clinical endpoint - mucosal healing. Various manufacturers are re-evaluating their products to determine the safety and efficacy of such dosing regimens. Although once widely employed in the treatment of Crohn's disease (CD), the accumulated body of evidence now suggests that there is a much more limited role for 5-ASA in this particular form of inflammatory bowel disease. Recent 5-ASA randomized-controlled trials, comparative studies, and outcomes research have led to refined treatment strategies and awareness for practitioners to better inform, engage and facilitate patients in optimal use of 5-ASA in inflammatory bowel disease.

Clinical pharmacology of 5-ASA compounds in inflammatory bowel disease

Mesalamine has been the first-line of therapy in patients with inflammatory bowel disease (IBD) since the 1960s. This article serves as a review of the different 5-aminosalicylic acid compounds, release formulations, use and dosing in the treatment of IBD, in particular ulcerative colitis.

[Chronic inflammatory intestinal diseases. Pathophysiology and therapy]

The pathogenesis and therapy of chronic inflammatory intestinal diseases are characterized by an obvious discrepancy. There is extensive agreement that the pathogenesis is substantially based on a disruption of the barrier of the intestinal mucous membrane against luminal bacteria. This has been demonstrated in recent years by evidence from various disciplines, in particular from genetics, microbiology, morphology and innate immunology. However, there is also the evidence-based therapy which, as in the past, is aimed against the effectors of the adaptive immune system. In this case the therapy with biologicals is more aggressive and takes the risk of a series of undesired side-effects. This dichotomy of pathological knowledge and therapeutic innovation is not only medically unsatisfactory but also makes it difficult to present a consistent picture of these symptoms. Despite this an attempt will be made to bridge these inconsistencies and to demonstrate possible future developments which will lead to a final causal therapy. An extended version of this article appears in our newly published book "Colitis ulcerosa und Morbus Crohn".

Effect of 5-aminosalicylates on renal function in patients with inflammatory bowel disease: 4-year follow-up study

OBJECTIVE

Nephrotoxicity has been described in some patients with inflammatory bowel disease (IBD) treated with 5-aminosalicylates (5-ASA). Our aim was to conduct a retrospective study of IBD patients, both with and without 5-ASA treatment, who underwent regular evaluation of renal function over a 4-year period.

METHODS

Serum creatinine was measured before the start of 5-ASA therapy, and thereafter yearly up to 4 years. Creatinine clearance (Cl(Cr)) was estimated from serum creatinine (Cockroft and Gault formula). The influence of 5-ASA treatment on renal function was assessed by univariate and multivariate analysis.

RESULTS

A total of 150 IBD patients (ulcerative colitis in 45%, Crohn's disease in 55%) were included. Sixty-two patients were receiving 5-ASAs (95% coated mesalazine, mean dose 1.9 +/- 0.8 g/day). Both serum creatinine levels and ClCr were similar in patients with and without 5-ASA treatment, and remained stable throughout the 4-year follow-up in patients taking 5-ASAs. In the multivariate analysis, 5-ASA treatment (or its dose) was not correlated with serum creatinine levels or Cl(Cr). No interstitial nephritis was reported during follow-up.

CONCLUSION

5-ASA-related renal disease was not found in our series, suggesting that the occurrence of renal impairment in IBD patients receiving these drugs is exceptional. Our results do not support the recommendation of serum creatinine monitoring in patients receiving 5-ASA treatment.

Renal effects of long-term treatment with 5-aminosalicylic acid

BACKGROUND

A number of case reports link the use of 5-aminosalicylic acid (5-ASA) to interstitial nephritis in patients with inflammatory bowel disease (IBD).

OBJECTIVE

To investigate whether the long-term use of 5-ASA has harmful effects on renal function in patients with IBD.

METHODS

A retrospective analysis of 171 consecutive outpatients with Crohn's disease or ulcerative colitis was conducted. Serum creatinine levels and body weight were measured before and after treatment to calculate the creatinine clearance (CrCl) rate.

RESULTS

In 171 patients (93 women, 78 men), the mean (+/- SD) dose of 5-ASA was 3.65+/-0.85 g/day with a cumulative dose of 11+/-7.7 kg over an interval of 8.4+/-5.9 years. Serum creatinine concentrations increased from 76.8 micromol/L to 88.7 micromol/L (n=171; P<0.0001) and the CrCl rate fell significantly from 104.6 mL/min to 93.1 mL/min (n=81; P<0.0001). There was one case of interstitial nephritis reported. Treatment groups included mesalamine (74.3%), sulfasalazine (15.2%) and combination (sulfalsalazine/mesalamine [10.5%]) with treatment durations of 7.2+/-4.5, 12.3+/-8.7 and 11.2+/-6.7 years, respectively. The duration of treatment was the most important covariate for change in CrCl and when analyzed by treatment group, those treated with sulfasazine had a strong correlation (r=-0.54, P=0.0145), while nonsignificant in the mesalamine group (r=0.06, P=0.7017). The decline in CrCl was negatively correlated with the pretreatment CrCl rate (r=-0.34; P=0.0024) and positively correlated with the mean daily dose of 5-ASA (r=0.32; P=0.0034).

CONCLUSION

The present study is the first to demonstrate a significant dose- and treatment duration-dependant decline in CrCl. The risks need to be further evaluated because 5-ASA is widely used for long-term maintenance therapy in patients with IBD.

Review article: new drug formulations, chemical entities and therapeutic approaches for the management of ulcerative colitis

BACKGROUND

Treatment options for ulcerative colitis (UC) are expanding with the development of novel drug formulations and dosing regimens and new chemical entities. Although the goals of medical therapy for UC remain unchanged, that is to induce and to maintain remission, focus has also centred on improving patient compliance, modifying the natural course of disease and healing the mucosa.

AIM

To examine novel formulations, new chemical entities and novel therapeutic approaches to the management of UC.

METHODS

Searches for all studies related to UC treatment in Medline and abstracts from major national and international meetings published in the last 10 years.

RESULTS

5-Aminosalicylic acids (5-ASA) remain the standard first-line treatment for patients with mild to moderately active UC. New formulations with altered delivery, and new dosing regimens have demonstrated possible improvements in efficacy compared with historically available preparations and dosing patterns. Once-daily dosing, micropellet formulations,and high-dose tablets offer enhanced efficacy and improved compliance. 5-ASA is now recognized as a ligand for peroxisome proliferator activated receptor-gamma (PPAR-gamma) and it has a role as a chemo-preventive agent in long-standing UC. New colonic release corticosteroid formulations help to limit systemic toxicity; turmeric, tacrolimus and infliximab have shown promising results. New anti-inflammatory targeted therapies include an anti-CD3 antibody, selective integrin blockers, anti-IL-2 antibody and PPAR-gamma agonists.

CONCLUSION

The evolution of novel oral 5-ASA formulations and dosage regimens,and recent development of new molecules have expanded the therapeutic armamentarium of UC.

Duration of treatment with 5-aminosalicylic acid compounds

The development of 5-aminosalicylic acid (5-ASA) therapy as a life long treatment for ulcerative colitis is reviewed from its origins in the 1940s to the present day. The drug was designed to treat rheumatoid arthritis, but was found helpful in the management of nine patients with ulcerative colitis. This discovery preceded the emergence of the clinical trial as a tool for assessing a new drug’s efficacy; as a result it lacked scientific rigour and was selective in its presentation of results. Nevertheless it identified the future cornerstone of therapy in ulcerative colitis. In 1962, the first double blind controlled trial of sulphasalazine was conducted on 40 patients. Outcome measures were subjective and included symptoms and an assessment of the rectal mucosa. In 1973, the first two papers on the role of sulphasalazine in maintenance of remission were published. Both used placebo controls and had a stratified design. Outcomes were measured using “an intention to treat” approach. The British study of 64 patients used both subjective and objective criteria to assess outcomes. Patients on placebo had a relapse rate four times patients on active treatment and this founded the basis for a life long approach to therapy with 5-ASA compounds in ulcerative colitis. However, in 1985, a small “on demand” study of 32 patients suggested this approach might be as effective as continuous treatment. Some support for this view came from an Italian study which showed no benefit to continued treatment for those in remission for two years or more. The central problem these studies identify is that of adherence to treatment in the long-term. Few studies have considered patients’ attitudes to continuous therapy and it is an area that needs further investigation.

Current therapy of inflammatory bowel disease in children

Ulcerative colitis (UC) and Crohn disease (CD) are chronic intestinal inflammatory diseases that can present as bloody diarrhea, abdominal pain, and malnutrition. Collectively, these disorders are referred to as inflammatory bowel disease (IBD). All patients with IBD share a common pathophysiology. However, there are a number of developmental, psychosocial, and physiologic issues that are unique to the approximate, equals 20% of patients that present during childhood or adolescence. These include the possibility of disease-induced delays in linear growth or physical development, differences in drug dosing, and the changes in social and cognitive development that occur as children move from school-age years into adolescence and early adulthood. Gastroenterologists caring for these children must therefore develop an optimal regimen of pharmacologic therapies, nutritional management, psychologic support, and properly timed surgery (when necessary) that will maintain disease remission, minimize disease and drug-induced adverse effects, and optimize growth and development. This article reviews current approaches to the management of patients with UC and CD and highlights issues specific to the treatment of children with IBD. The principal medical therapies used to induce disease remission in patients with UC are aminosalicylates (for mild disease), corticosteroids (for moderate disease), and cyclosporine (ciclosporin) (for severe disease). If a patient responds to the induction regimen, maintenance therapies that are used to prevent disease relapse include aminosalicylates, mercaptopurine, and azathioprine. Colectomy with creation of an ileal pouch anal anastomosis (J pouch) has become the standard of care for patients with severe or refractory colitis and results in an improved quality of life in most patients. Therefore, the risks associated with using increasingly potent immunosuppressant agents must be balanced in each case against a patient's desire to retain their colon and avoid a temporary or potentially permanent ileostomy. Decisions about drug therapy in the management of patients with CD are more complex and depend on both the location (e.g. gastroduodenal vs small intestinal vs colonic), as well as the behavior of the disease (inflammatory/mucosal vs stricturing vs perforating) in a given patient. Induction therapies for CD typically include aminosalicylates and antibiotics (for mild mucosal disease), nutritional therapy (including elemental or polymeric formulas), corticosteroids (for moderate disease), and infliximab (for corticosteroid-resistant or fistulizing disease). Aminosalicylates, mercaptopurine, azathioprine, methotrexate, and infliximab can be used as maintenance therapies. Because surgical treatment of CD is not curative, it is typically reserved for those patients either with persistent symptoms and disease limited to a small section of the intestine (e.g. the terminal ileum and cecum) or for the management of complications of the disease including stricture or abdominal abscess. When surgery is necessary, maintenance medications administered postoperatively will postpone recurrence. Patients with UC and CD are at risk for the development of micronutrient deficiencies (including folate, iron, and vitamin D deficiencies) and require close nutritional monitoring. In addition, patients with UC and CD involving the colon are at increased risk of developing colon cancer, and should be enrolled into a colonoscopy surveillance program after 8-10 years of disease duration.

Effect of once- or twice-daily MMX mesalamine (SPD476) for the induction of remission of mild to moderately active ulcerative colitis

BACKGROUND & AIMS

SPD476 (MMX mesalamine), a novel, once-daily mesalamine formulation, uses MMX Multi Matrix System (MMX) technology to delay and extend delivery of active drug throughout the colon. We performed a randomized, double-blind, parallel-group, placebo-controlled, multicenter phase III study in patients with mild to moderately active ulcerative colitis.

METHODS

Two hundred eighty patients with mild to moderately active ulcerative colitis received MMX mesalamine 2.4 g/day given twice daily (n = 93), 4.8 g/day given once daily (n = 94), or placebo (n = 93) for 8 weeks. The primary end point was the percentage of patients in clinical and endoscopic remission (modified ulcerative colitis disease activity index score of < or =1, with a score of 0 for rectal bleeding and stool frequency, and at least a 1-point reduction in sigmoidoscopy score) at week 8. Patients with mucosal friability were not considered to have achieved this end point.

RESULTS

Clinical and endoscopic remission at week 8 was achieved by 34.1% and 29.2% of patients receiving MMX mesalamine 2.4 g/day given twice daily and MMX mesalamine 4.8 g/day given once daily, respectively, versus 12.9% receiving placebo (P < .01). MMX mesalamine was generally well-tolerated.

CONCLUSIONS

MMX mesalamine given once or twice daily is well-tolerated and, compared with placebo, demonstrated efficacy for the induction of clinical and endoscopic remission in mild to moderately active ulcerative colitis.

Indications for 5-aminosalicylate in inflammatory bowel disease: is the body of evidence complete?

Mesalazine is a safe drug, although adverse events may be seen in a minority of patients. This applies also to pregnant women and children. The role of mesalazine in combination therapy to improve efficacy and concomitant drug pharmacokinetics, or in chemoprevention against inflammatory bowel disease (IBD)-related colonic carcinoma has not yet been completely elucidated. Therapeutic success of mesalazine may be optimized by a combination of high dose and low frequency of dosage to improve compliance. Therefore, due to its superior safety profile and pharmacokinetic characteristics, mesalazine is preferable to sulphasalazine. This paper reviews the literature concerning mechanisms of action, indications and off-label use, pharmacokinetic properties and formulations, therapeutic efficacy, compliance, paediatric indications, chemoprevention, and safety issues and adverse event profile of mesalazine treatment versus sulphasalazine. It also highlights these controversies in order to clarify the potential benefits of mesalazines in IBD therapy and evidence for its use.

How important is onset of action in ulcerative colitis therapy?

Pharmacotherapy is the cornerstone of management in ulcerative colitis. However, controversy remains over optimal medical strategies. Specifically, differences in the onset of action of various drug therapies are thought to influence the achievement and maintenance of remission of disease, yet this is poorly characterised. There is a wide range of recent data concerning aminosalicylates, with much debate as to the relative merits of the various formulations and delivery systems. Meta-analyses confirm the efficacy of aminosalicylates for the induction and maintenance of remission and suggest that the newer agents are comparable in efficacy to sulfasalazine. Among aminosalicylates, data from clinical trials reveal that the onset of action is earlier with balsalazide than mesalazine. Although the efficacy of the newer 5-aminosalicylate agents is no greater than that of sulfasalazine, they have better adverse effect profiles. Factors such as tolerability and adherence appear more important than onset of action in long-term maintenance. Corticosteroids have long been used in the treatment of ulcerative colitis, yet there is a paucity of data regarding this. They have a rapid onset of action but considerable systemic adverse effects. Therefore, corticosteroids are reserved for disease that fails to respond to other agents or for primary therapy in patients with severe disease, although there is no universal acceptance of a threshold at which to initiate corticosteroid treatment.Rectal preparations of both aminosalicylates and corticosteroids have been developed in an attempt to exert a more rapid and direct onset of action while minimising adverse systemic effects. In clinical trials, topical preparations of both aminosalicylates and corticosteroids are effective in inducing remission. However, patient acceptability and proximal extent of disease dictate selection of a topical agent more than concern with rate of onset.A wide range of immunomodulators have been investigated in patients with steroid-refractory ulcerative colitis. The thioguanine derivatives are the most widely used but have a limited evidence base to support this use with controlled trials providing equivocal results regarding efficacy in severe ulcerative colitis. In addition, the thioguanine derivatives have a protracted onset of action and a considerable serious adverse effect profile. Calcineurin inhibitors and methotrexate have a more rapid onset of action than the thiopurines but have even less data to support their widespread use. They are widely regarded as salvage therapy and further data are required. Regarding biological agents, infliximab revolutionised the treatment of Crohn's disease, yet results in ulcerative colitis have been disappointing. Further trials are ongoing with great anticipation for more favourable data. The practical clinical implications of any differences between the agents depend on patient satisfaction with various therapies. Noncompliance is a major concern in maintenance therapy and is probably associated with relapse. Dose administration schedules and acceptability of therapy appear to be important factors in adherence. Overall, it is not clear that onset of action has a major influence on patient adherence and addressing issues of compliance may have more direct clinical impact.

[Consequences of galenic considerations and clinical results for therapy of ulcerative colitis]

Corticosteroids and 5-amino salicylic acid (5-ASA) are established therapies in the induction of remission and in maintenance of remission in patients with ulcerative colitis. 5-ASA exists in different delivery systems, however, clinical studies directly comparing these preparations exist only in very limited numbers. When analyzing placebo-controlled or comparative studies it is clearly evident that 5-ASA is superior to placebo in both induction of remission and maintenance therapy. In maintenance therapy prodrug compounds (sulfasalazine, SASP) seem to be marginally better compared to 5-ASA slow release preparations. Direct comparison of the newer 5-ASA preparations is not possible because of limited data. Theoretical considerations based on the different principles of slow release are also questionable since the intraluminal pH or intestinal motility may be disturbed in IBD.