Oral delayed-release mesalazine: a review of its use in ulcerative colitis and Crohn's disease

Delayed-release oral mesalamine tablet mimicking a small jejunal gastrointestinal stromal tumor: A case report

BACKGROUND

Enteric-coated medications are supposed to pass intact through the gastric environment and to release the drug content into the small intestine or the colon. Before dissolution of the enteric coating, they may appear hyperdense on computed tomography (CT). Unfortunately, few reports have been published on this topic so far. In this case report, the hyperdense appearance on contrast-enhanced CT of an enteric-coated mesalamine tablet was initially misinterpreted as a jejunal gastrointestinal stromal tumor (GIST).

CASE SUMMARY

An asymptomatic 81-year-old male patient, who had undergone laparoscopic right nephrectomy four years earlier for stage 1 renal carcinoma, was diagnosed with a jejunal GIST at the 4-year follow-up thoraco-abdominal CT scan. He was referred to our hub hospital for gastroenterological evaluation, and subsequently underwent 18-fluorodeoxyglucose positron emission tomography, abdominal magnetic resonance imaging, and video capsule endoscopy. None of these examinations detected any lesion of the small intestine. After reviewing all the CT images in a multidisciplinary setting, the panel estimated that the hyperdense jejunal image was consistent with a tablet rather than a GIST. The tablet was an 800 mg delayed-release enteric-coated oral mesalamine tablet (Asacol^®), which had been prescribed for non-specific colitis, while not informing the hospital physicians.

CONCLUSION

Delayed-release oral mesalamine (Asacol^®), like other enteric-coated medications, can appear as a hyperdense image on a CT scan, mimicking a small intestinal GIST. Therefore, a detailed knowledge of the patients’ medications and a multidisciplinary review of the images are essential.

Efficacy of a Preparation Based on Calcium Butyrate, Bifidobacterium bifidum, Bifidobacterium lactis, and Fructooligosaccharides in the Prevention of Relapse in Ulcerative Colitis: A Prospective Observational Study

Several compounds based on short chain fatty acids and/or probiotics/prebiotics have shown promising results in the therapy of ulcerative colitis (UC), possibly due to its key role in restoring gut homeostasis as well as intestinal barrier integrity. Here, we investigated the efficacy of a patented preparation based on calcium butyrate, Bifidobacterium bifidum, Bifidobacterium lactis, and fructooligosaccharides (FEEDColon®, Princeps, Cuneo, Italy) in maintaining remission and improving subjective symptoms and inflammatory indices in patients with UC receiving 5-ASA therapy. A total of 42 patients were prospectively recruited and randomized in 21 patients receiving combination therapy with mesalamine (5-ASA) plus FEEDColon® and 21 patients treated with standard 5-ASA therapy. Patients were assessed at baseline, at 6-month, and 12-month follow-up (FU). Therapeutic success (defined as Mayo partial score ≤ 2 and faecal calprotectin (FC) < 250 µg/g at 12-month FU) was reached by 32 (76%) patients: 20 (95%) among those treated with 5-ASA + FeedColon®, and 12 (57%) among those treated with 5-ASA only (p = 0.009). Consistently, patients treated with combination therapy improved subjective symptoms (quality of life, abdominal pain, and stool consistency) and reduced FC values, while those treated with 5-ASA alone, improved neither subjective symptoms nor FC during the FU. In conclusion, FEEDColon® supplementation appears to be a valid add-on therapy for the maintenance of remission in patients with UC. Further multicentre, placebo-controlled, double-blind clinical trials are needed to validate our results on larger cohorts of patients with UC.

In vitro and in vivo evaluation of a sustained-release once-a-day formulation of the novel antihypertensive drug MT-1207

Hypertension is one of the most common chronic cardiovascular disorders. Sustained-release formulations are developed to maintain drug therapeutic levels throughout the treatment of hypertension, to promote patient compliance and improve patient outcomes. We have developed and tested in in vivo trials a once-a-day tablet formulation for the novel antihypertensive drug MT-1207. The tablets based upon a hydrophilic polymer matrix underwent post-compression parameter and physicochemical characterisations, along with in vitro drug release testing. The most promising formulation containing 31% w/w HPMC K15M gave a 24-hour release of MT-1207 with an almost constant release rate up to 20 hours. Follow in in vivo studies were carried out in Beagle dogs for the optimised sustained-release tablets in comparison to immediate-release tablets. The results showed that a sustained release of MT-1207 from the new formulation was achieved with a drug t_1/2 2-2.5 times longer than the immediate-release tablets. Moreover, the AUC_0-24h values of both sustained- and immediate-release tablets were identical at the same dose of 30 mg, indicating that the same amount of drug was absorbed in each case. For treatments based upon MT-1207, this development is significant for future commercial exploitation via scale-up and further trials, and for improved patient outcomes.

The Usefulness of Microencapsulated Sodium Butyrate Add-On Therapy in Maintaining Remission in Patients with Ulcerative Colitis: A Prospective Observational Study

Butyrate is a short-chain fatty acid that plays a key role in maintaining gut homeostasis as well as the integrity of the intestinal barrier. In the present study, we investigated the effect of oral microencapsulated sodium butyrate (BLM) administration in maintaining remission and improving residual symptoms and inflammatory markers in a population of patients with ulcerative colitis (UC). Forty-two patients with UC in clinical remission were enrolled in the study. Three patients were lost to follow up; 39 patients (18 treated with BLM add-on therapy and 21 with standard mesalamine only) that reached 12 months of follow up were included in the final analysis. Therapeutic success (defined as Mayo partial score ≤ 2 and faecal calprotectin (FC) < 250 µg/g at 12 months of follow up) was achieved in 25 patients (64.1%); 15/18 (83.3%) in BLM group and 10/21 (47.6%) in control group (p = 0.022). Consistently, 13/18 patients (72.2%) receiving BLM improved residual symptoms compared to 5/21 patients (23.8%) in control group (p = 0.003). FC values significantly diminished from the baseline to the end of follow up in patients that received BLM, while FC values remained almost stable in the control group. In conclusion, oral BLM supplementation appears to be a valid add-on therapy in order to maintain remission in patients with UC. Further randomized, placebo-controlled, double-blind clinical trials are needed to validate our results on a larger population or cohort of patients.

CF₃-Substituted Mollugin 2-(4-Morpholinyl)-ethyl ester as a Potential Anti-inflammatory Agent with Improved Aqueous Solubility and Metabolic Stability

Although mollugin, the main ingredient of the oriental medicinal herb Rubia cordifolia, has considerable anti-inflammatory effects, it has poor aqueous solubility as well as poor metabolic and plasma stability. To overcome these shortfalls, various mollugin derivatives have been synthesized and evaluated for their ability to inhibit U937 monocyte cell adhesion to HT-29 colonic epithelial cells in TNF-α- or IL-6-induced models of colon inflammation. The 2-(4-morpholinyl)-ethyl ester of CF3-substituted mollugin (compound 15c) showed good water solubility, improved metabolic and plasma stability, and greater inhibitory activity than mesalazine in both the TNF-α- and IL-6-induced colonic epithelial cell adhesion assays, suggesting that 15c is a potential anti-inflammatory agent.

Evaluating clinical, dietary, and psychological risk factors for relapse of ulcerative colitis in clinical, endoscopic, and histological remission

BACKGROUND AND AIM

The literature on possible factors that could trigger a relapse in patients with ulcerative colitis (UC) in clinical, endoscopic, and histological remission on long-term follow up is scarce. To determine the relapse rate in patients with UC in clinical, endoscopic, and histological remission and identify factors that may influence the risk of relapse.

METHODS

Patients with UC in clinical, endoscopic, and histological remission were enrolled between January and July 2010 and followed up for 1 year to determine the effect of clinical, dietary, and psychological factors on relapse. Information regarding factors that may affect relapse such as infection, antibiotic, or non-steroidal anti-inflammatory drugs (NSAIDs) use and any other factor that the patient felt important and compliance with medications was obtained.

RESULTS

Ninety-seven patients (59 males, mean age 39 ± 11.9 years) were followed up for a mean duration of 9 ± 2.3 months. Eighteen (18.6%) relapsed with the median time to relapse being 3.5 months. On univariate analysis, more relapsers had significantly higher NSAIDs use within 15 days of relapse, respiratory tract infection within 4 weeks, use of steroids more than once in past, higher consumption of calcium, riboflavin, and vitamin A, and lower consumption of sugars. On multivariate analysis, NSAIDs use (HR [95% CI]: 6.41 [1.88-21.9]) and intake of vitamin A (HR [95% CI]: 1.008 [1.000-1.016]) were statistically significant predictors of relapse.

CONCLUSION

With a relapse rate of 18.6% over a follow up of 9 months in patients with UC in clinical, endoscopic, and histological remission, independent predictors of relapse were history of NSAIDs use within 15 days of relapse and higher intake of vitamin A.

Pre- and posttherapy assessment of intestinal soluble mediators in IBD: where we stand and future perspectives

Inflammatory bowel disease (IBD) is a chronic inflammatory condition characterized by an abnormal immune response against food or bacterial antigens in genetically predisposed individuals. Several factors of innate and adaptive immune system take part in the inflammatory process, probably actively contributing in endoscopic and histological healing at molecular level. Although it is difficult to discriminate whether they are primary factors in determining these events or they are secondarily involved, it would be interesting to have a clear map of those factors in order to have a restricted number of potentially "good candidates" for mucosal healing. The present review will present a class of these factors and their modulation in course of therapy, starting from pathogenic studies involving several treatments associated with good clinical outcomes. This approach is meant to help in the difficult task of identifying "good candidates" for healing signatures, which could also be possible new therapeutic targets for clinical management of IBD patients.

Scavenging of reactive oxygen and nitrogen species by the prodrug sulfasalazine and its metabolites 5-aminosalicylic acid and sulfapyridine

Sulfasalazine is a prodrug composed by a molecule of 5-aminosalicylic acid (5-ASA) and sulfapyridine (SP), linked by an azo bond, which has been shown to be effective in the therapy of inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease, as well as of rheumatic diseases, such as rheumatoid arthritis and ankylosing spondylitis. The precise mechanism of action of sulfasalazine and/or its metabolites has not been completely elucidated, though its antioxidant effects are well established and are probably due to its scavenging effects against reactive oxygen and nitrogen species (ROS and RNS), as well as metal chelating properties, in association to its inhibitory effects over neutrophil oxidative burst. The present work was focused on screening and comparing the potential scavenging activity for an array of ROS (O(2)(•-), H(2)O(2), (1)O(2), ROO(•) and HOCl) and RNS ((•)NO and ONOO(-)), mediated by sulfasalazine and its metabolites 5-ASA and SP, using validated in vitro screening systems. The results showed that both 5-ASA and sulfasalazine were able to scavenge all the tested ROS while SP was practically ineffective in all the assays. For HOCl, (1)O(2), and ROO(•), 5-ASA showed the best scavenging effects. A new and important finding of the present study was the strong scavenging effect of 5-ASA against (1)O(2). 5-ASA was shown to be a strong scavenger of (•)NO and ONOO(-). Sulfasalazine was also able to scavenge these RNS, although with a much lower potency than 5-ASA. SP was unable to scavenge (•)NO in the tested concentrations but was shown to scavenge ONOO(-), with a higher strength when the assay was performed in the presence of 25 mM bicarbonate, suggesting further scavenging of oxidizing carbonate radical. In conclusion, the ROS- and RNS-scavenging effects of sulfasalazine and its metabolites shown in this study may contribute to the anti-inflammatory effects mediated by sulfasalazine through the prevention of the oxidative/nitrative/nitrosative damages caused by these species.

[Effectiveness of new, once-daily 5-aminosalicylic acid in the treatment of ulcerative colitis]

5-aminosalicylate (5-ASA) agents remain the mainstay treatment in ulcerative colitis (UC). A number of oral 5-ASA agents is commercially available, including azo-bond pro-drugs such as sulfasalazine, olsalazine and balsalazide, and delayed- and controlled-release forms of mesalazine. In addition, the effectiveness of oral therapy relies on good compliance, which may be adversely affected by frequent daily dosing and a large number of tablets. Furthermore, poor adherence has been shown to be an important barrier to successful management of patients with UC. Recently, new, once-daily formulations of mesalazine including the unique multi-matrix delivery system and mesalazine granules were proven to be efficacious in inducing and maintaining remission in mild-to-moderate UC, with a good safety profile comparable to that of other oral mesalazine formulations. In addition, they offer the advantage of low pill burden and may contribute to increased long-term compliance and treatment success in clinical practice and might potentially further contribute to a decline in the risk for UC-associated colon cancers. In this systematic review, the authors summarize the available literature on the short- and medium-term efficacy and safety of the new once-daily mesalazine formulations.

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.

In-vitroandIn-vivoEvaluation of Mesalazine–Guar Gum Matrix Tablets for Colonic Drug Delivery

The aim of this study was to develop colon-specific delivery systems for mesalazine (5-ASA) using guar gum as a carrier. A colon specific matrix tablet of mesalazine with guar gum was evaluated by in vitro and in vivo X-ray studies in humans. Two different types of guar gum were used in the experiments. Tablets were prepared by the slugging method. The physical properties of tablets were tested and in vitro release studies were performed by a flow-through cell apparatus with and without galactomannanase enzyme. The type and the amount of guar gum affected the in vitro release of drug from the matrix tablets. High viscosity guar gum, in the form of a matrix tablet was capable of protecting the drug from being released in the upper region of gastrointestinal (GI) system, i.e. stomach and small intestine. X-ray imaging technique was used to monitor the tablets throughout the GI system on 8 healthy volunteers. Barium sulphate was used as a marker in the tablets for in vivo studies. These results showed that, the matrix tablets reached the colon; not being subjected to disintegration in the upper region of the GI system in all the subjects.

Improving delivery of aminosalicylates in ulcerative colitis: effect on patient outcomes

Developments in drug delivery technology have expanded the formulations of 5-aminosalicylic acid (5-ASA) available to clinicians over the last 50 years. Delivery of adequate doses of 5-ASA to the colon can be achieved by pH-dependent, delayed-release or pro-drug formulations. Despite some variations in the pharmacokinetics between individual preparations, the clinical effects in induction of response and maintenance of remission in ulcerative colitis appear to be consistent. Direct comparison studies between different preparations have yielded similar results in primary endpoints, although differences in secondary endpoints or post hoc analyses have been noted. The development of delivery methods that allow once-daily administration represents a potential means to improve the low medication adherence rates reported in patients with ulcerative colitis.

Delayed-release Multi Matrix System (MMX) mesalazine: in ulcerative colitis

* Mesalazine appears to act locally on the mucosa of the colon and reduces the inflammation associated with ulcerative colitis. * Following oral administration, the majority (*78%) of a dose of delayed-release Multi Matrix System (MMX) mesalazine passes unabsorbed through the upper gastrointestinal tract to reach and traverse the entire length of the colon. * In a well designed phase III trial in patients with active, mild to moderate ulcerative colitis (n = 262), significantly (p < 0.01) more MMX mesalazine 2.4 (34%) or 4.8 g/day (29%) recipients than placebo recipients (13%) achieved clinical and endoscopic remission after 8 weeks of treatment.* In a second phase III trial (n = 341), clinical and endoscopic remission rates with MMX mesalazine 2.4 (40.5%) and 4.8 g/day (41.2%) were significantly (p < 0.01) greater than with placebo (22.1%) after 8 weeks, while the remission rate with non-MMX delayed-release mesalazine (Asacol) [32.6%] did not differ from placebo.* Overall, MMX mesalazine was generally well tolerated in controlled clinical trials, with a similar incidence of treatment-emergent adverse events in placebo (66%) and MMX mesalazine (56%) recipients in a pooled analysis; most adverse events were of mild or moderate severity. Two of 434 MMX mesalazine recipients experienced serious adverse events that were considered treatment related (pancreatitis caused by mesalazine sensitivity).

Is once-daily mesalazine equivalent to the currently used twice-daily regimen? A study performed in 30 healthy volunteers

A randomized, 2-way, crossover study was conducted in 30 volunteers to compare the pharmacokinetic profile of a new once-daily dosing regimen of mesalazine (1 x 4 g/d) with the current twice-daily dosage (2 x 2 g/d) used in many European countries. The 2 dosages were administrated orally for 8 days, separated by a 2-week washout. Plasma concentrations of mesalazine and N-acetyl-mesalazine were determined on days 1 and 8 by a validated high-performance liquid chromatography method and C(max), t(max), and AUCs calculated. The bioequivalence was obtained for a 90% confidence interval of the AUC(0-24h) ratio (test/reference) for mesalazine and N-acetyl-mesalazine on days 1 and 8, within the range of 0.80 to 1.25. The bioequivalence was demonstrated on day 1 for mesalazine and N-acetyl-mesalazine and on day 8 for mesalazine. As it is desirable to offer patients a preparation with a less frequent administration to enhance compliance, this once-daily regimen may be an attractive dosing option.

Colon-specific delivery of 5-aminosalicylic acid from chitosan-Ca-alginate microparticles

Chitosan-Ca-alginate microparticles for colon-specific delivery and controlled release of 5-aminosalicylic acid after peroral administration were prepared using spray drying method followed by ionotropic gelation/polyelectrolyte complexation. Physicochemical characterization pointed to the negatively charged particles with spherical morphology having a mean diameter less than 9 microm. Chitosan was localized dominantly in the particle wall, while for alginate, a homogeneous distribution throughout the particles was observed. (1)H NMR, FTIR, X-ray and DSC studies indicated molecularly dispersed drug within the particles with preserved stability during microencapsulation and in simulated in vivo drug release conditions. In vitro drug release studies carried out in simulated in vivo conditions in respect to pH, enzymatic and salt content confirmed the potential of the particles to release the drug in a controlled manner. The diffusional exponents according to the general exponential release equation indicated anomalous (non-Fickian) transport in 5-ASA release controlled by a polymer relaxation, erosion and degradation. Biodistribution studies of [(131)I]-5-ASA loaded chitosan-Ca-alginate microparticles, carried out within 2 days after peroral administration to Wistar male rats in which TNBS colitis was induced, confirmed the dominant localization of 5-ASA in the colon with low systemic bioavailability.

Evaluation of alginate based mesalazine tablets for intestinal drug delivery

The aim of this study was to develop the alginate based mesalazine tablets for intestinal delivery. Sodium alginate is a biocompatible, natural polymer with pH-sensitive gel-forming ability. Matrix tablets were prepared with two types of sodium alginate of different amounts. The in vitro release characteristics of mesalazine from alginate tablets were compared with those of the commercial product (Salofalk). X-ray imaging was used to monitor the tablets throughout the gastrointestinal system. Although alginate tablets gave a faster release in an acidic medium compared with the commercial product (Salofalk), the cumulative amount of released drug of the optimum formulation was found to be almost the same as that of the commercial product at the end of 4 h. The alginate type and amount in the matrices played an important role in basic media. The release of the optimum formulation containing low viscosity alginate was found to be almost identical to that of the commercial product in acidic and basic media. Tablets were visualized to determine whether they were located in the terminal ileum or cecum for 3-6 h. Mesalazine-alginate matrix tablet formulations can deliver the drug to the small and large intestine. Thus, the alginate matrix system may be a promising system for the treatment of Crohn's disease involving both the ileum and large intestine.

Antioxidant screening of medicinal herbal teas

Herbal tea consumption is deeply and widely rooted amongst South-American populations. In view of the involvement of oxygen- and nitrogen-reactive species in the ethiogenesis of several diseases, the antioxidant properties of some of the herbal teas most commonly consumed in the southern regions was assessed in vitro. Around one-third of the 13 examined herbs, displayed a substantially higher ability to scavenge ABTS(+.) radicals (TEAC assay), and to quench the pro-oxidant species, hypochlorite (HClO) and peroxynitrite (ONOO(-)). Amongst the tested herbs, teas prepared from Haplopappus baylahuen, Rosa moschata and Peumus boldus showed the highest TEAC and HClO-quenching activities. These herbs were around 5- to 7-fold more potent than the least active herbs. Based on the TEAC assay, 150 mL of tea prepared from H. baylahuen, R. moschata and P. boldus would be equivalent to around 200 mg of Trolox). Teas from H. baylahuen and P. boldus were also found to be particularly potent in quenching HClO. In the ONOO(-) assay, H. baylahuen and Buddleia globosa showed the highest activities. The results obtained suggest that the regular consumption of teas prepared from some of these herbs may be useful potentially to provide the organism with molecules capable of protecting the gastrointestinal tract against certain pathologically relevant oxidant species.

Life events and inflammatory bowel disease relapse: a prospective study of patients enrolled in remission

OBJECTIVES

The impact of life events in recurrence of inflammatory bowel disease (IBD) is unclear. We sought to determine whether stressful life events or the emotional impact of these events are associated with IBD relapses, hypothesizing that the exposure of life events among patients with inactive disease will increase the risk of subsequent relapses.

METHODS

In this prospective study, 163 patients with inactive IBD, who had had at least one relapse in a 2-yr period before entry into the study, were enrolled. The Spanish version of the Social Readjustment Rating Scale (SRRS) (measuring life events), a measure of the emotional impact of these life events, and an IBD activity index were completed monthly up to the end of the study (maximum 11 months) or up to a relapse. Biological factors associated with an increased risk of relapse were identified in patients who relapsed.

RESULTS

Fifty-one patients relapsed (32.9%), 104 remained in remission, and 8 dropped out. Multivariate Cox regression analysis with time dependent variables showed that the number of life events was not associated with the rate of relapse after adjustment for significant covariates on the subsequent month (hazard ratio = 0.88, 95% CI = 0.68-1.13, p = 0.33) or in the time-lagged analysis. The emotional impact of stressful events was also not associated with the risk of relapse. When patients who suffered a biological risk factor for relapsing were excluded in subsequent statistical analyses, similar results were obtained.

CONCLUSIONS

Our results suggest that stressful life events do not trigger exacerbations in patients suffering from IBD.

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.

Experimental research on treatment of ulcerative colitis with integrative traditional Chinese and Western medicine

AIM: To explore the effect of the clyster treatment with integrated traditional Chinese and Western medicine on ulcerative colitis (UC), and to investigate its mechanism.

METHODS: The mouse model of UC was established, and then the rats were treated (clyster) with the combination of tin-like powder, dexamethasone, gentamicin, and berberine. Then the therapeutic effect was observed, and the mechanism of the treatment was analyzed.

RESULTS: The disease active index (DAI) and histopathologic score (HPS) of the low dose (DAI: 5.10±4.07, HPS: 8.00±6.38), the moderate dose (DAI: 0.80±1.87, HPS: 1.30±1.49), the high dose (DAI: 1.00±1.94, HPS: 0.90±1.45), and the positive control group (DAI: 5.30±4.37, HPS: 8.00±5.12) were markedly lower than those of the negative control group (DAI: 8.60±1.26, HPS: 13.20±1.69) (all P <0.05). The DAI and HPS of the moderate dose group were markedly lower than those of the low dose group and the positive control group (all P <0.05), but there was no significant difference between the moderate and high dose group (P >0.05). The levels of interleukin-4 (IL-4) of the low, moderate, and high dose group, and the positive control group were markedly lower than those of the negative control group (32.33±15.30, 25.79±6.33, 29.92±12.81, 28.45±9.30 vs 63.89±11.31, all P <0.05), but the levels of interferon-γ (IFN-γ) were markedly higher than those of the negative control group (198.38±31.46, 187.49±13.04, 188.14±14.11, 207.64±41.44 vs 127.41±21.47, all P <0.05).

CONCLUSION: The combination enema of tin-like powder, dexamethasone, gentamicin, and berberine has definite therapeutic effect on UC, which may be related with its regulation on IL-4 and IFN-γ level.

Colonic targeting of aminosalicylates for the treatment of ulcerative colitis

Aminosalicylates (5-aminosalicylic acid) represent drugs of first choice in the treatment of ulcerative colitis. Two different therapeutic approaches have been employed to target the active 5-aminosalicylic acid to its site of action. Either inactive azo-prodrugs (e.g. sulfasalazine, olsalazine, balsalazide) or special galenic formulations have been developed for topical delivery of 5-aminosalicylic acid to the colon. However, as intestinal physiology, the extent of ulcerative colitis as well as drug disposition demonstrate large interindividual differences, acute healing rates (40-80%) and the maintenance of remission are quite variable. Apparently, therapeutic effects depend on local concentrations of 5-aminosalicylic acid in the colonic mucosa whereas systemic drug exposure might be one determinant of side effects. In general, 5-aminosalicylic acid is well tolerated and withdrawal from therapy is rare. Following administration of azo-prodrugs (e.g. olsalazine), lower plasma concentrations and higher delivery into the colon of 5-aminosalicylic acid can be observed in comparison to special galenic formulations of 5-aminosalicylic acid. Whether such changes in drug disposition will affect therapeutic efficacy remains to be proved by clinical data. Consequently, selection of a particular agent should be based primarily on clinical efficacy, profile of adverse effects, patients' acceptance and economic considerations.

Multicentre randomized-controlled clinical trial of Ipocol, a new enteric-coated form of mesalazine, in comparison with Asacol in the treatment of ulcerative colitis

BACKGROUND

5-Aminosalicylates remain important in the treatment of ulcerative colitis, but it is uncertain if the various preparations currently available are equivalent given the different delivery systems that exist. Generic prescription of mesalazine (mesalamine) is therefore inappropriate. Ipocol has recently become available as an alternative to Asacol-MR.

AIM

To compare the two agents in a controlled trial using a non-inferiority design.

METHODS

Eighty-eight ulcerative colitis patients with a mild to moderate clinical relapse were randomized to one of the two drugs at a daily dose of 2.4 g for 8 weeks. Safety was the key concern; the primary measured end-point was efficacy as judged from a colitis activity index.

RESULTS

There were no unexpected adverse events of clinical consequence. The colitis score improved similarly in both patient groups (by 2.3 with Ipocol and by 1.5 with Asacol: not significant), and a similar proportion was in clinical remission at the end of the study (26.1% for Ipocol and 28.6% for Asacol: not significant). Systemic steroids were needed in 11.9% of the Asacol-treated patients compared with 6.5% with Ipocol (not significant).

CONCLUSION

It appears appropriate to conclude that, while not identical to Asacol-MR, Ipocol offers a safe and similarly effective alternative.

A new oral delivery system for 5-ASA: preliminary clinical findings for MMx

BACKGROUND

Multi-matrix (MMx), a new delivery system for mesalazine, seems to release 5-aminosalicyclic acid (5-ASA) preferentially in the sigmoid colon. This study had 2 objectives: (1) to evaluate the therapeutic response to MMx in patients with active left-sided disease and (2) to gain additional insights as to how the therapy would compare with topical 5-ASA.

METHODS

Patients received either 1.2 g of 5-ASA MMx three times per day plus placebo enema or 4 g of 5-ASA enema plus placebo tablets for 8 weeks. The primary endpoint was clinical remission (clinical activity index < or =4) at 8 weeks. Secondary endpoints were endoscopic and histologic remissions.

RESULTS

Seventy-nine patients were enrolled. Clinical remission rates at 4 and 8 weeks were 57.5% and 60.0% for patients treated with MMx and 68.4% and 50.0% for patients randomized to 5-ASA enemas, respectively (95% confidence interval for the difference at 8 weeks, -12 to +32). Endoscopic remission was achieved by 45.0% of patients on 5-ASA MMx and by 36.8% of those on enema, whereas 15.0% and 8% of patients, respectively, showed histologic remission. Compliance was 97.0% for oral and 87.5% for topical therapy. In the enema group, compliance was 88.0% for the patients in remission and 65.5% for those with active disease.

CONCLUSIONS

Preliminary studies suggest that similar rates for induction of remission can be expected from 5-ASA enemas and MMx for patients with left-sided ulcerative colitis.

Topical delivery of therapeutic agents in the treatment of inflammatory bowel disease

For targeting local and systemic inflammatory processes in inflammatory bowel disease (IBD) therapeutic agents of first choice (e.g. aminosalicylates, corticosteroids) have been developed in special galenic forms to accomplish the topical delivery of the active compounds to the terminal ileum (Crohn's disease) and/or the colon (Crohn's disease and ulcerative colitis). However, it has to be realized that intestinal physiology (e.g. motility, intraluminal pH profiles), extent and pattern of IBD as well as drug disposition demonstrate large interindividual differences resulting in variable clinical response rates between about 35% and 75%. 5-Aminosalicylate (5-AS) can be delivered to the colon either by azo-prodrugs (e.g. sulfasalazine, olsalazine or balsalazide) or by direct rectal administration of 5-AS in form of enemas, foam or suppositories. Such formulations will be only effective in patients with ulcerative colitis (UC). Various slow/controlled release preparations of 5-AS have been developed for oral use. Some of them (e.g. Pentasa, Salofalk) release sufficient 5-AS already in the small bowel which could provide some additional benefit in Crohn's disease (CD). As urinary and faecal recoveries of total 5-AS are similar for all oral formulations, no major clinical differences can be expected. Extent of the disease, profile of adverse effects and patient's acceptance provide some guidance for selection of the particular agent. Rectal installation of several glucocorticosteroids has been employed for many years. More recently scientific and clinical interest has been focused on budesonide which is extensively presystemically metabolized in the intestinal wall and the liver. Therefore, its systemic availability is low (10-15%) independent whether budesonide is administered orally as controlled release formulation in patients with CD or rectally as enema in patients with UC. Numerous pharmacokinetic and clinical studies have documented the anticipated topical delivery and clinical efficacy of this corticosteroid without serious side effects such as cushingoid features. It can be assumed that for any novel therapeutic principle in IBD the approach of topical delivery will be also tried.

Severe ulcerative colitis: prospective study of parameters determining outcome

BACKGROUND

One-third of patients with exacerbations of ulcerative colitis (UC) require colectomy and 1% die. Although several studies have reported parameters associated with failure of medical treatment, studies using multivariate analysis of various predictors are scanty.

METHODS

Demographic, clinical and laboratory parameters within 48 h of admission of 50 consecutive patients (55 episodes) were prospectively recorded. Each episode was treated with intravenous hydrocortisone, antibiotics and fluid administration. The data of patients who failed to respond, deteriorated, developed complications requiring emergency surgery or died within 7 days of hospitalization, were compared with the data of those who responded during this period using Mann-Whitney U-test or chi-squared tests. Variables found to be significant on univariate analysis were entered into a multivariate model.

RESULTS

Medical treatment failed in 10 of 55 episodes; eight had surgery (one died), another died with bowel perforation and peritonitis and one left hospital in a moribund state. Younger age, pedal edema, transverse colonic diameter >5 cm on abdominal radiograph, low hemoglobin, low serum albumin, high C-reactive protein, presence of fibrin degradation product (FDP) in serum, low serum fibrinogen, prolonged prothrombin time, Truelove-Witt's fulminant disease, and high clinical activity index were associated with failure of medical treatment on univariate analysis. All the above variables were significant by multivariate analysis except age, serum albumin level and presence of FDP.

CONCLUSION

It may be possible to predict the failure of medical treatment in exacerbations of UC using a scoring system based on clinical parameters and simple laboratory tests.

Current therapeutic recommendations: infliximab for ulcerative colitis

Randomized, controlled studies have shown that infliximab, the chimeric anti-tumor necrosis factor alpha (TNF-alpha) antibody, is effective for the treatment of active and fistulizing Crohn's disease. Because infliximab is beneficial in patients with Crohn's disease, in whom other therapies have failed, it has been postulated that infliximab may also be helpful in patients with ulcerative colitis. Many investigators have studied the effectiveness of infliximab in ulcerative colitis, mainly in patients who are refractory to corticosteroids. Unfortunately, these studies have not yielded a conclusive answer to the efficacy of infliximab in inducing remission in patients with severe ulcerative colitis. However, some have reported excellent results and others less effective, with the overall data being inconclusive. The purpose of this review is to summarize the current literature on the use of infliximab in ulcerative colitis, as well as to provide insight into the possible mechanisms of why it may or may not work in these difficult-to-treat patients.

Psychosocial determinants of relapse in ulcerative colitis: a longitudinal study

OBJECTIVES

To determine the association between psychosocial characteristics and time to relapse in patients with inactive ulcerative colitis.

METHODS

Sixty patients with clinically and endoscopically inactive ulcerative colitis were followed for 1 yr, or less if they relapsed. Demographic, psychosocial, and clinical data were obtained. Stressful life events (Psychiatric Epidemiology Research Interview Life Events Scale), psychological distress (Symptom Checklist-90R), and perceived stress (Perceived Stress Scale) were recorded monthly by self-report. Multivariate time-dependent Cox regression was used to identify the independent determinants of earlier time to clinical relapse.

RESULTS

The patients' mean age was 39 yr (SD = 9.4), 37 (62%) were female, and 22 (37%) relapsed during the 1-yr follow-up. Univariate Cox regression indicated a weak association between number of stressful events in the preceding month and time to relapse (p = 0.09). This association strengthened in multivariate analysis (p = 0.02, hazard ratio = 1.26 per event, 95% CI = 1.04-1.53) after adjustment for significant covariates.

CONCLUSIONS

After controlling for demographic and clinical variables, more recent stressful events were associated with earlier time to relapse. These findings, which support a biopsychosocial model of disease, might help clinicians identify patients who might benefit from more intensive maintenance medical therapy and behavioral medicine interventions to reduce stress and improve coping.

Review article: Oral, modified-release mesalazine formulations--proprietary versus generic

Products containing mesalazine have been used in the treatment of inflammatory bowel disease for many years. Many of the oral, modified-release products are reaching the point of patent expiration, and it is expected that several new 'generic' versions will be developed. As mesalazine acts topically, the drug needs to be available at the site of inflammation to be effective. For this reason, the currently available products have been developed with individual formulations so that physicians have a choice when matching the different release profiles to the site and extent of disease. As such, the current guidelines state that oral, delayed-release mesalazine formulations are not interchangeable and should be prescribed by their proprietary (brand) name. The standard regulatory assessment process for generic or 'copy' products, using systemic bioequivalence data, does not appear to be sufficient when evaluating topically acting, oral, modified-release products. We therefore recommend that the regulatory bodies should require that new, oral mesalazine products should be assessed by a combination of dissolution, bioequivalence and (a minimum of one) adequately powered, comparative trial to determine therapeutic equivalence. Of most importance here is that the assessment of new modified-release products is sufficiently rigorous to allow patients and physicians to be confident in their use.

Budesonide (Entocort EC Capsules): a review of its therapeutic use in the management of active Crohn's disease in adults

Budesonide (Entocort EC Capsules) is an oral corticosteroid with a high degree of topical activity and low systemic bioavailability (approximately 11%). This action is achieved by a high affinity for the glucocorticoid receptor and an extensive first-pass hepatic metabolism. The budesonide capsule has been formulated to dissolve in a pH dependent manner, delivering most of the drug to the ileum and ascending colon, areas of the intestine most commonly affected by Crohn's disease. In large (n > or = 176), well designed clinical trials of 10 to 12 weeks' duration in patients with active, mild to moderate Crohn's disease, budesonide (9 mg/day) was significantly more effective in inducing remission than placebo or mesalazine (mesalamine) slow release, and demonstrated similar efficacy to recommended dosages of prednisolone. Results of health-related quality-of-life assessments support clinical data, showing a significantly greater improvement among patients treated with budesonide than with placebo or mesalazine slow release. Oral budesonide was well tolerated in clinical trials of up to 16 weeks' duration. In these studies, the incidence of adverse events associated with budesonide (9 mg/day) was similar to that seen with placebo and mesalazine slow release. The rate of glucocorticoid-related adverse effects observed with budesonide was significantly less than that reported with prednisolone.

CONCLUSION

Oral budesonide 9 mg/day offers efficacy that is superior to mesalazine slow release and placebo, and similar to prednisolone in the treatment of patients with active mild to moderate Crohn's disease involving the ileum and/or ascending colon. Budesonide is generally well tolerated and the incidence of adverse events is similar to that seen with placebo or mesalazine slow release. Glucocorticoid-related adverse effects are significantly less frequent during short-term therapy with budesonide than with prednisolone. Thus, for the medical management of patients with active mild to moderate Crohn's disease, oral budesonide has superior efficacy to mesalazine slow release and a more favourable tolerability profile than prednisolone.

Determination of 5-aminosalicylic acid in pharmaceutical formulation by differential pulse voltammetry

The oxidative behaviour of 5-aminosalicylic acid (5-ASA) has been investigated by differential pulse voltammetry using a glassy carbon electrode in different buffer systems. Linear sweep voltammetry was used to study the influence of pH on the peak current and peak potential. The solution conditions and instrumental parameters were optimized to obtain a good sensitivity. The Britton-Robinson buffer of pH 1.81 was selected as a suitable analytical medium in which 5-ASA exhibited a sensitive diffusion controlled oxidative peak at 0.564 V (vs. Ag/AgCl). The peak current varied linearly with drug concentration in the range between 1 x 10(-4) and 2 x 10(-6) M. The proposed voltammetric method has been applied to the determination of the drug in commercial delayed-release tablet forms. A mean recovery of 101.23% with a relative standard deviation of 1.35% was obtained.

Systematic review: the pharmacokinetic profiles of oral mesalazine formulations and mesalazine pro-drugs used in the management of ulcerative colitis

AIM

: To quantify through systematic review the pharmacokinetic profiles of the oral delayed release and sustained release mesalazine (5-aminosalicylate, 5ASA) formulations (Asacol, Salofalk, Mesasal, Claversal, Pentasa) and pro-drugs (sulfasalazine, olsalazine, balsalazide) used in the management of ulcerative colitis.

METHODS

: Selected articles had: (1) adult healthy volunteers or patients with ulcerative colitis and (2) quantification of pharmacokinetic data to include, at a minimum, urinary excretion of total 5ASA [5ASA plus N-Acetyl-5ASA (N-Ac-5ASA)].

DATA COLLECTION AND ANALYSIS

: Pharmacokinetic data (Tmax, Cmax, AUC, urinary excretion, faecal excretion) of 5ASA, its major metabolite N-Acetyl-5ASA, total 5ASA, and the parent pro-drug compounds was extracted.

MAIN RESULTS

: The summary results for urinary excretion of total 5ASA over 24-96 h in all subjects (either mean or median) were: sulfasalazine mean 11-33% or median 22%; olsalazine mean 14-31% or median 16-27%; balsalazide mean 12-35% or median 20%; Asacol mean 10-35% or median 18-40%; Pentasa mean 15-53% or median 23-34%; Salofalk, Mesasal and Claversal mean 27-56% or median 31-44%. The summary results for faecal excretion of total 5ASA over 24-96 h in all subjects (either mean or median) were: sulfasalazine mean 23-75% or median 38%; olsalazine mean 47-50% or median 17-36%; balsalazide mean 46% or median 22%; Asacol mean 40-64% or median 20-56%; Pentasa mean 12-51% or median 39-59%; Salofalk, Mesasal and Claversal mean 37-44% or median 23-35%.

CONCLUSIONS

: The systemic exposure to 5ASA, as measured by urinary excretion of total 5ASA, and the faecal excretion of total 5ASA is comparable for all oral mesalazine formulations and pro-drugs. Thus, selection of a mesalazine therapy for the treatment of ulcerative colitis should be based on other factors such as efficacy, dose-response, toxicity of the parent compound and its metabolites, compliance issues related to dose forms and dosing schedules, and costs.

Balsalazide: a review of its therapeutic use in mild-to-moderate ulcerative colitis

The aminosalicylate balsalazide is a prodrug which is metabolised by bacterial azo reductases in the colon to release its therapeutically active moiety mesalazine [mesalamine (US) or 5-aminosalicylic acid] and an inert carrier molecule. The systemic absorption of balsalazide and its metabolites is not required for the therapeutic efficacy of the drug, and has been demonstrated to be limited. Data from well designed trials with a duration of 8 to 12 weeks show that oral balsalazide 6.75 g/day is as effective as (two trials) or more effective than (one trial) oral delayed-release (pH-dependent) mesalazine 2.4 g/day and appears to be as effective as oral sulfasalazine 3 g/day in the treatment of active mild-to-moderate ulcerative colitis. In addition, balsalazide appears to have a faster onset of action than mesalazine. Furthermore, balsalazide was as effective as delayed-release mesalazine (dosages used were 1.2 and 1.5 g/day, where 1.6 g/day is recommended) and oral sulfasalazine 2 g/day (recommended dosage) in the prevention of relapse in ulcerative colitis in remission after 6 to 12 months of treatment; the balsalazide dosage was 3 g/day versus mesalazine and 2 g/day versus sulfasalazine. Although not well established, additional benefits may be achieved with balsalazide dosages up to 6 g/day. Data from well designed, 2- to 12-month trials show that balsalazide is well tolerated by patients with ulcerative colitis in both acute and maintenance indications, and is better tolerated than standard formulations of sulfasalazine at therapeutically relevant dosages.

CONCLUSION

Balsalazide is a well tolerated and effective first-line therapeutic option for patients with ulcerative colitis, both for the treatment of active mild-to-moderate disease and as maintenance therapy to prevent disease relapse.

Pharmacokinetic considerations in the treatment of inflammatory bowel disease

This review describes the pharmacokinetics of the major drugs used for the treatment of inflammatory bowel disease. This information can be helpful for the selection of a particular agent and offers guidance for effective and well tolerated regimens. The corticosteroids have a short elimination half-life (t1/2beta) of 1.5 to 4 hours, but their biological half-lives are much longer (12 to 36 hours). Most are moderate or high clearance drugs that are hepatically eliminated, primarily by cytochrome P450 (CYP) 3A4-mediated metabolism. Prednisone and budesonide undergo presystemic elimination. Any disease state or comedication affecting CYP3A4 activity should be taken into account when prescribing corticosteroids. Depending on the preparation used, 10 to 50% of an oral or rectal dose of mesalazine is absorbed. Rapid acetylation in the intestinal wall and liver (t1/2beta 0.5 to 2 hours) and transport probably by P-glycoprotein affect mucosal concentrations of mesalazine, which apparently determine clinical response. Any clinical condition influencing the release and topical availability of mesalazine might modify its therapeutic potential. Metronidazole has high (approximately 90%) oral bioavailability, with hepatic elimination characterised by a t1/2beta of 6 to 10 hours and a total clearance of about 4 L/h/kg. Ciprofloxacin is largely excreted unchanged both renally (about 45% of dose) and extrarenally (25%), with a relatively short t1/2beta (3.5 to 7 hours). Thus, renal function affects the systemic availability of ciprofloxacin. Both mercaptopurine and its prodrug azathioprine are metabolised to active compounds (6-thioguanine nucleotides; 6-TGN) by hypoxanthine-guanine phosphoribosyltransferase and to inactive metabolites by the polymorphically expressed thiopurine S-methyltransferase (TPMT) and xanthine oxidase. Patients with low TPMT activity have a higher risk of developing haemopoietic toxicity. Both mercaptopurine and azathioprine have a short t1/2beta (1 to 2 hours), but the t1/2beta of 6-TGN ranges from 3 to 13 days. Therapeutic response seems to be related to 6-TGN concentration. Almost complete bioavailability has been observed after intramuscular and subcutaneous administration of methotrexate, which is predominantly (85%) excreted as unchanged drug with a t1/2beta of up to 50 hours. Thus, renal function is the major determinant for disposition of methotrexate. Cyclosporin is slowly and incompletely absorbed. It is extensively metabolised by CYP3A4/5 in the liver and intestine (median t1/2beta and clearance 7.9 hours and 0.46 L/h/kg, respectively), and inhibitors and inducers of CYP3A4 can modify response and toxicity. Infliximab is predominantly distributed to the vascular compartment and eliminated with a t1/2beta between 10 and 14 days. No accumulation was observed when it was administered at intervals of 4 or 8 weeks. Methotrexate may reduce the clearance of infliximab from serum.

Medical therapy for ulcerative colitis

Although newer therapeutic agents are being developed for the treatment of inflammatory bowel disease, aminosalicylates and corticosteroids remain the mainstay of treatment for UC (Tables 2-5). Patients who do not respond to these agents or become steroid dependent require immunomodulatory therapy or curative surgery. Cyclosporine represents the greatest treatment advance for UC in 10 years. The role of nicotine, heparin, antibiotics, probiotics, and SCFA in the treatment of UC is less clear, but these agents may offer an alternative therapeutic approach for patients intolerant or nonresponsive to standard therapy.

Oral versus combination mesalazine therapy in active ulcerative colitis: a double-blind, double-dummy, randomized multicentre study

BACKGROUND

Oral and topical mesalazine formulations are effective in active ulcerative colitis, but little is known on the efficacy of combined treatment.

AIM

To compare the efficacy of oral mesalazine vs. combined oral and topical mesalazine in mildly to moderately active ulcerative colitis.

METHODS

Patients with mildly to moderately active ulcerative colitis (Clinical Activity Index, CAI 4-12) were identified at 15 participating centres. They were randomized to receive either mesalazine 4 g orally plus placebo enema, or mesalazine 2 g orally plus mesalazine 2 g rectally as a liquid enema for 6 weeks. The rate of clinical remission (CAI < 4) or clinical remission/improvement (reduction of CAI of 50% from baseline) at 6 weeks and time to clinical remission/improvement were primary end-points; the rate of endoscopic remission was a secondary end-point.

RESULTS

67 patients were assigned to oral treatment and 63 to combined treatment. One patient in the oral group and 2 in the combined group discontinued the treatment due to adverse events. Following an intention-to-treat analysis, the rate of clinical remission was 82% for oral treatment and 87% for combined treatment (P=0.56); the mean time to remission 22.2 and 20.2 days, respectively (P=0.29); the rate of clinical remission/improvement and the rate of endoscopic remission were 85% and 91% (P=0.503) and 58% and 71% (P=0.21), respectively.

CONCLUSIONS

In patients with mild active ulcerative colitis, mesalazine 4 g orally and 2 g orally plus 2 g enema are equally effective in inducing disease remission.

Clinical, biological, and histologic parameters as predictors of relapse in ulcerative colitis

BACKGROUND & AIMS

Ulcerative colitis (UC) is a chronic relapsing inflammatory bowel disease. We aimed to assess whether clinical, biological, and histologic parameters in quiescent UC predict time to clinical relapse.

METHODS

Seventy-four patients with clinically and endoscopically determined inactive UC were followed up for 1 year or for a shorter period if they had a relapse. Serum erythrocyte sedimentation rate; C-reactive protein, interleukin (IL)-1beta, IL-6, and IL-15 values; anti-neutrophil cytoplasmic antibody titers; and rectal biopsy specimens were obtained at baseline, at 6 and 12 months, and/or at relapse. Multivariate survival analysis was performed to determine independent predictors of clinical relapse.

RESULTS

Twenty-seven patients relapsed (19/42 women; 8/32 men). Multivariate Cox regression analysis retained younger age (P = 0.003; hazard ratio, 0.4 per decade), greater number of prior relapses in women (P < 0.001; hazard ratio, 1.6 per prior relapse), and basal plasmacytosis (P = 0.003; hazard ratio, 4.5) on rectal biopsy specimens as predictors of shorter time to clinical relapse. Kaplan-Meier survival curves showed the 20-30-year-old age group and women with more than 5 prior relapses to be groups with shorter times to relapse.

CONCLUSIONS

Younger age, multiple previous relapses (for women), and basal plasmacytosis on rectal biopsy specimens were independent predictors of earlier relapse. These findings may help identify patients with inactive UC who will require optimal maintenance medical therapy.

Clinical pharmacokinetics of slow release mesalazine

Slow release oral mesalazine (Pentasa) contains microgranules covered by a semipermeable ethylcellulose membrane. The microgranules continuously release their content from duodenum to ileum in a pH- and time-dependent way. About 75% of the microgranules pass into the colon, where further release is slower. This release pattern does not appear to be affected by food, diarrhoea or the simultaneous use of H2 antagonists. Rectal forms of mesalazine deliver active drug directly to the rectum and left colon. Plasma concentrations of mesalazine and its metabolite acetyl-5-aminosalicylic acid after oral or local administration are the result of systemic absorption and hepatic metabolism by N-acetyltransferase. Most studies report maximal plasma concentrations of less than 1 mg/L after oral administration of slow release mesalazine, much lower than those observed after uncoated mesalazine but generally higher than after azo-bound drugs such as sulfasalazine. Urinary recovery is an indicator of absorption and metabolism, and is lower after rectal administration (10 to 30%) than after oral administration (30 to 40%). Faecal recovery after oral administration of slow or delayed release mesalazine is lower than with azo-bound drugs. Mesalazine acts locally after absorption by colonic and ileal mucosa. Mean steady-state concentrations of 25.7+/-2.2 microg/kg wet weight are found in ileocolonic biopsy specimens from patients with irritable bowel syndrome treated for 1 week with slow release mesalazine 1.5 g/day. Intramucosal concentrations after slow release mesalazine differ little between healthy individuals and patients with inflammatory bowel disease. Although significant differences are found between the various aminosalicylates in release patterns and the resulting pharmacokinetic parameters, no differences in therapeutic effects have been found in comparative studies. High doses of oral mesalazine (2 to 4 g/day) are more effective than lower doses in the treatment of patients with mild to moderate active ulcerative colitis. High doses (4 g/day) are also effective in the treatment of Crohn's disease, predominantly in patients with ileitis. In contrast, no dose ranging effects were demonstrated with local treatment forms: mesalazine 1g enema seems sufficient for patients with distal colitis. Higher serum concentrations and urinary recoveries after the administration of slow or delayed release mesalazine compared with azo-bound drugs suggest a higher risk for renal adverse effects, although the reported occurrence is extremely low. Although preliminary data support an association between mucosal concentrations of mesalazine and its clinical activity, further studies are needed to correlate the effects of this drug with its pharmacokinetic parameters.

Mono- and biphasic plasma concentration-time curves of mesalazine from a 500 mg suppository in healthy male volunteers controlled by the time of defecation before dosing

This study was based on data from a bioequivalence study (n=24) of two different formulations of suppositories containing 500 mg mesalazine (formulation I and II), with a similar dissolution profile in phosphate buffer pH 6.8. There was a large intra- and intersubject variability in the plasma concentration-time curves of mesalazine from both suppositories. The aim of the investigation was to identify the parameters that caused the observed large variations in release and absorption of mesalazine in the rectum. Plasma mesalazine and acetylmesalazine, and urine acetylmesalazine concentrations were determined according to validated methods involving HPLC analysis with coulometric detection. Lower limit of quantitation values were respectively 10.4 and 19.4 ng mL(-1) in plasma and 0.96 microg mL(-1) in urine. The time of defecation before and after insertion was recorded. There was a clear distinction between subjects who showed monophasic mesalazine release/absorption and those who showed biphasic and more extended release/absorption. With formulation I there was a correlation between time of defecation before dosing and the type of absorption, monophasic and biphasic absorbers showed a significant difference in the time of defecation, e.g. 9.7+/-5.6 h vs 18.8+/-11.9 h (P = 0.0218). The impact of time of defecation before dosing was non-significant with formulation II, 16.7+/-7.2 h vs 15.1+/-4.2 h (P = 0.67). The impact of the time elapsed between administration and time of defecation after the insertion of the suppository was not significant for the type of release/absorption. The plasma concentration-time curves of the metabolite ran parallel to that of the parent drug, the more parent drug was released/absorbed, the more was acetylated (P = 0.0013) and excreted into the urine (P = 0.0004). After absorption the compound was metabolized into acetylmesalazine, and renally excreted (12-13% of the dose). Monophasic release/ absorption resulted in 7.1% metabolite with I and 10.3% with II (P = 0.0004), while biphasic release/absorption gave 16.8% metabolite with I and 15.5% with II. The renal clearance of the metabolite acetylmesalazine was independent of the observed defecation patterns (300 mL min(-1), P > 0.8), stool composition, and type of absorption.