Long-term management of Crohn's disease with mesalamine capsules (Pentasa). Pentasa Crohn's Disease Compassionate Use Study Group

Current long-term treatment of Crohn's disease is unsatisfactory. Based on the Crohn's Disease Activity Index (CDAI), this multicenter trial enrolled patients with either active Crohn's disease (CDAI > or = 150) or disease in remission (CDAI < 150). The primary measure of therapeutic response was mean change in CDAI from baseline to final visit. All patients began treatment with a dosage of < or = 4 g/day of mesalamine that ranged from 3.7 g at baseline to 3.4 g at final visit. Overall, 467 patients were enrolled: 333 (active disease) and 134 (remission). The median study participation time was 14 months. For patients entering with active disease, the mean reduction in CDAI was 77 points, with 42% (122/289) achieving remission by their final visit. For patients entering in remission, there was an increase in mean CDAI from 90 at baseline to 96 at final visit, with 79% (95/120) of patients in remission at final visit and 72% (31/43) in remission continuously after 12 months of therapy. From baseline to final visit, the mean prednisone dose decreased 5 mg/day in patients with active disease and 11 mg/day in patients in remission. Mesalamine was well tolerated and no adverse laboratory trends were observed. These results suggest that controlled-release mesalamine shows promise as a steroid-sparing agent and as a safe and effective long-term therapy for the induction of and maintenance of remission of mild-to-moderate Crohn's disease.

Scintigraphic study of gastrointestinal transit and disintegration sites of mesalazine tablets labeled with technetium-99m

Tablets of mesalazine covered with a pH-dependent coating (Pentacol), labeled by an original technique with technetium-99m, were administered to 12 patients, 9 with Crohn's disease, 3 of which recurrent, 1 with ulcerative colitis, and 2 with irritable bowel syndrome, with the aim of verifying in vivo the intestinal site of disintegration and how the contents spread throughout the intestine. In all cases the tablet was broken down in the distal ileum at extremely variable intervals, from 5 to 27 h, and the contents spread into the nearby loops and into the colon. The notable differences in the residence time of the whole tablet in the ileum can be explained by differences in adhesion to the inflamed mucosa and by a lower pH in the part of the ileum affected by the disease.

Evaluation of the physicochemical properties and dissolution characteristics of mesalamine: relevance to controlled intestinal drug delivery

The physicochemical properties of mesalamine and the effect of pH and buffer concentration on the dissolution rate of pure mesalamine and mesalamine with Carbopol 974P were investigated. The aqueous solubilities at 25 and 37 degrees C were 0.844 and 1.41 mg/mL, respectively. Consistent with the observed pKa1 (2.30) and pKa2 (5.69) or mesalamine, the solubility-pH profile is increased at pH < 2.0 and pH > 5.5 and is minimized from pH 2.0 to pH 5.5. The flux data were consistent with the solubility data from pH 1.0 to pH 5.5. The flux increased and plateaued at pH values 5.5 to 7.0 and was dependent on the bulk buffer concentration. At low bulk buffer concentrations, mesalamine reduces the pH in the diffusion layer, which results in a decrease in flux. The medium with the highest buffer capacity has a greater ability to increase the surface pH and dissolution rate. The addition of Carbopol reduces the flux and the sensitivity of the dissolution rate of mesalamine to increasing bulk buffer concentration. This reduction is postulated to be due to neutralization of the basic dissolution media, gel formation, and possible drug-polymer interactions.

Localization of drug release sites from an oral sustained-release formulation of 5-ASA (Pentasa) in the gastrointestinal tract using gamma scintigraphy

Release of 5-ASA from a sustained release formulation (Pentasa, Ferring A/S, Copenhagen, Denmark) was monitored with plasma sampling for up to 24 hours in nine volunteers under both fasted and fed conditions. Drug absorption was correlated with location of the sustained-release microgranules in the gastrointestinal tract by gamma scintigraphy. Disintegration of the labeled tablet preparation occurred in the stomach within 20 minutes and acetylated 5-ASA was detectable in the plasma less than 60 minutes after ingestion. No significant differences were detected in either transit times through the small intestine, peak plasma acetylated 5-ASA concentration or lag time to absorption between fasted and fed individuals. Peak plasma concentration of acetylated 5-ASA usually occurred when the microgranules were present in the small intestine or ascending colon. The pharmacoscintigraphic study confirmed that 5-ASA release from the formulation occurred throughout the gastrointestinal tract, and that food effects on the in vivo behavior of the preparation were minimal.

Mesalamine capsules for treatment of active ulcerative colitis: results of a controlled trial. Pentasa Study Group

The efficacy of a capsule formulation of mesalamine was assessed in 374 patients with mild to moderately active ulcerative colitis. Patients, stratified to pancolitis or left-sided disease, received either placebo or mesalamine at 1, 2, or 4 g daily for 8 wk. Efficacy was assessed using clinical improvement--physician global assessment, sigmoidoscopic index, biopsy score, trips to the toilet, and clinical symptoms (abdominal pain, urgency, stool consistency, and rectal bleeding)--and induction of remission (more stringent criteria for physician global assessment, sigmoidoscopic index, and biopsy score). For physician global assessment of treatment benefit, 79% and 84% of patients on the 2-g and 4-g doses of mesalamine, respectively, received treatment benefit, compared with 54% on placebo (p < or = 0.0002). For the physician global assessment of treatment success, both the 2-g and 4-g doses of mesalamine were superior to placebo (57% and 59% of patients, p = 0.0021 and 0.0012, respectively), compared with 36% on placebo. Both the 2-g and 4-g doses produced statistically significant macroscopic (endoscopic) improvement compared with placebo (p < 0.004). The 4-g dose also produced a statistically significant microscopic (histologic) improvement compared to placebo (p < 0.002). Significant improvement compared to placebo was also observed at 2 g and 4 g for the four clinical symptoms and trips to the toilet (p < or = 0.003). Oral mesalamine capsules were significantly superior to placebo for inducing remission, with 29% of patients at 2 g and 29% at 4 g achieving remission by physician global assessment, compared with 12% on placebo. Forty-four percent and 48% of patients receiving 2 g and 4 g of mesalamine, respectively, achieved remission by sigmoidoscopic index (p < 0.05), compared with 31% on placebo. Thirty-nine percent of patients at 4 g daily achieved microscopic remission, compared with 23% on placebo (p < 0.03). Treatment response was not affected by extent of disease or prior steroid or sulfasalazine therapy. These data suggest that controlled-release mesalamine capsules are a safe and effective monotherapy in doses of 2-4 g daily for treating mild to moderately active ulcerative colitis, as well as for inducing remission, regardless of prior oral steroid or sulfasalazine therapy or extent of disease.

Slow-release 5-aminosalicylic acid therapy in children with small intestinal Crohn's disease

Pharmacologic agents effective in the treatment of Crohn's disease confined to the small intestine are limited. The therapeutic efficacy of oral mesalazine in small bowel inflammation, although theoretically promising, remains unproven. In an open-labeled initial trial, timed-release 5-aminosalicylic acid (5-ASA), administered at a daily dosage of 30.6 +/- 9.0 mg/kg (mean +/- SEM) to children with active Crohn's disease involving the small intestine, was associated with improvement on the Harvey index in six of 12 patients treated for 8.1 +/- 3.9 weeks. In a subsequent prospective, double-blind study 14 children, ages 9.3 to 16.1 years, with active Crohn's disease limited radiologically in the small intestine were randomized to receive either timed-release 5-ASA [50 mg/kg/day (maximum 3 g/day)] or placebo for 8 weeks. Following a 4-week washout period, patients crossed over to receive the other study drug for a further 8 weeks. Six children completed the entire 20-week trial. The van Hees index improved among patients receiving 5-ASA for 8 weeks (delta = -18 +/- 6.4) but deteriorated among patients given placebo (delta = +14 +/- 4.1) (p < 0.05). Mean Crohn's Disease Activity Index (CDAI) decreased marginally after 8 weeks of 5-ASA treatment (delta = -48 +/- 38.2) but not with placebo (delta = -3.0 +/- 7.9) (p = 0.31). Of the eight noncompleters, more patients dropped out of the study because of lack of therapeutic response to placebo (n = 5) than to 5-ASA (n = 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Review article: the mode of action of the aminosalicylates in inflammatory bowel disease

Sulphasalazine and other 5-aminosalicylic acid (5-ASA)-containing drugs are used in the treatment of acute inflammatory bowel disease and in the maintenance of clinical remission. Despite their use for over 50 years, the mechanism of action of this class of drugs remains uncertain, although a number of possibilities are discussed in this review. It seems likely that the aminosalicylates are important free radical scavengers, can reduce leukotriene production and can inhibit the cellular release of interleukin-1, all of which are likely to be important in reducing the acute inflammatory response in inflammatory bowel disease. The effects of these drugs on prostaglandin production are more contentious, but it appears that 10(-5) to 10(-4) M concentrations stimulate production of prostaglandins which may be cytoprotective, while higher doses of these drugs inhibit prostaglandin production. The aminosalicylates may maintain remission in inflammatory bowel disease by preventing leucocyte recruitment into the bowel wall. The drugs inhibit the chemotactic response to leukotriene B4, reduce the synthesis of platelet activating factor and also inhibit leucocyte adhesion molecule upregulation.

Mesalamine capsules for the treatment of active Crohn's disease: results of a 16-week trial. Pentasa Crohn's Disease Study Group

BACKGROUND

Mesalamine is released from sulfasalazine in the colon and benefits colonic Crohn's disease. The mesalamine used in this study releases the drug throughout the small bowel and colon. Therefore, this study was designed to detect benefit for Crohn's disease involving the small bowel alone or both the colon and small bowel.

METHODS

This double-blind, randomized, multicenter prospective controlled trial compared placebo and three daily doses of mesalamine in 310 patients. The primary outcome criterion was change in the Crohn's Disease Activity Index (CDAI) from baseline to final study visit.

RESULTS

Patients taking 4 g/day mesalamine experienced a decrease of 72 CDAI points compared with 21 points in the placebo group (P < 0.01). Remission occurred in 43% of the 4-g group and 18% of the placebo group. Patients with ileum-only disease showed a 93-point improvement on 4 g mesalamine, compared with a 2-point improvement in similar patients on placebo. Mesalamine in this trial was not associated with clinically significant toxicity.

CONCLUSIONS

This controlled-release mesalamine preparation is safe and effective at 4 g/day as a single agent in treatment of active Crohn's disease of the ileum and colon.

Oroileal transit of slow release 5-aminosalicylic acid

The predominant active anti-inflammatory moiety in chronic inflammatory bowel disease is 5-aminosalicylic acid (5-ASA). As unprotected 5-ASA is rapidly absorbed in the upper gastrointestinal tract several slow release preparations have been developed to permit passage of 5-ASA to the lower small bowel and to the colon. To investigate luminal kinetics and extent of the release of 5-ASA intraluminal concentrations and loads of this compound together with that of its main metabolite acetyl-5-aminosalicylic acid (ac-5-ASA) were studied, over 15 hours after giving the slow release preparation Salofalk at a dose of 500 mg orally together with a test meal. Plasma concentrations and urinary excretion were also measured. Six healthy volunteers swallowed an 11 lumen oroileal tube, which allowed marker perfusion, aspiration of luminal content from the duodenum, mid-jejunum, and ileum, and recording of intestinal motility. Emptying of 5-ASA into the duodenum started after emptying of the meal, together with the first phase III of interdigestive motility. Mean luminal concentrations of 5-ASA and ac-5-ASA increased continuously from duodenum (both: 15 to 30 micrograms/ml) to ileum (60 to 110 micrograms/ml and 80 to 150 micrograms/ml respectively) over three hours and decreased over the next three hours. During 10 hours after eating, 30% of the total dose passed the ileum in solution and another 10% were excreted in urine. Thus about 60% reached the colon unreleased from tablets and another 30% were in solution. The ratio of 5-ASA and ac-5-ASA in solution was about 1:1 in the duodenum and 1:1.5 to 1:2 in the more distal small intestine. The data suggest that the large quantities of intraluminal ac-5-ASA are generated in the intestinal mucosa and reach the lumen by back diffusion. The results show that most of the 5-ASA from this slow release preparation is delivered into the colon, which explains its effectiveness in ulcerative colitis. The considerable luminal concentrations already present in the distal ileum might justify therapeutic trials in Crohn's disease.

Comparison of bismuth citrate and 5-aminosalicylic acid enemas in distal ulcerative colitis: a controlled trial

An enema that contained a complex of bismuth citrate and polyacrylate was compared with 5-aminosalicylic acid (5-ASA) enemas for treatment of distal ulcerative colitis. The multicentre trial involving 63 patients was randomised and double blind with enemas given over four weeks; clinical, sigmoidoscopic, and histological assessments were made. Improvements were seen in both treatment groups. Clinical remission was seen in 18 of 32 patients treated with 5-ASA and 12 of 31 patients treated with bismuth citrate-carbomer (chi 2 1.94; p = 0.16). Sigmoidoscopic remission occurred in 20 of 32 patients in the 5-ASA group and 15 of 31 patients given bismuth (chi 2 1.27; p = 0.26). Improvement of rectal biopsy histology by at least one grade was seen in 16 of 32 patients in the 5-ASA group and 14 of 31 patients with bismuth (chi 2 0.15; p = 0.70). Analysis of covariance gave no significant difference between groups, although there was a trend favouring 5-ASA. There was no evidence of bismuth accumulation during the trial. Bismuth enemas may offer a new therapeutic option in distal ulcerative colitis.

Successful treatment of pyoderma gangrenosum with topical 5-aminosalicylic acid

Pyoderma gangrenosum in a twenty-nine-year-old woman with associated long-standing Crohn's disease was treated with topical 5-aminosalicylic acid cream. Significant improvement in the ulceration occurred despite progressive deterioration of the inflammatory bowel disease. The possible mode of action is reviewed. The efficacy, together with the lack of side effects, warrants further study into the therapeutic role of topical 5-aminosalicylic acid.

Comparison of the effect of oral sulphasalazine, sulphapyridine and 5-amino-salicylic acid on the in vivo antibody response to oral and systemic antigen

1. Mice, whose drinking water contained sulphasalazine, sulphapyridine or 5-amino-salicylic acid, received an antigenic challenge by cholera toxin administered either orally or systemically. 2. Sulphasalazine treated mice made less specific antibody of IgA class provided the antigen also was administered orally (P = 0.009 for days 7-28). When the antigen was administered systemically, there was a vigorous anti-cholera toxin antibody response of IgG class, and a lesser IgM but only a weak IgA response. The effect of sulphasalazine in this case was confined to the IgG response, which was significantly suppressed on day 28 (P = 0.008). 3. Sulphapyridine and 5-amino salicylic acid had no significant effect on the anti-cholera toxin (CT) responses of all three classes. 4. It therefore appears that in this model, only sulphasalazine is capable of influencing the humoral immune system, the antibody class affected depending on the route of entry of antigen. This may have implications for conditions such as rheumatoid arthritis and chronic inflammatory bowel disease, for which sulphasalazine has been found useful.

[Local or systemic treatment of inflammatory bowel diseases?]

Standard therapy of inflammatory bowel disease is based on the treatment with corticosteroids, sulfasalazine and 5-aminosalicylic acid. Depending on localization, extent and activity of the bowel inflammation, these drugs are administered topically, systemically or in combination. The advantage of the topical therapy is the lack of non allergic side effects. Ulcerative proctitis and left-sided colitis should, in the first approach, be treated topically with suppositories or enemas. In severe colitis, a combined systemic and topical therapy is useful. In Crohn's disease topical agents are of minor importance. 5-aminosalicylic acid is efficient in mildly active Crohn's disease and prevents relapse for some patients in remission. In severely active Crohn's disease, systemic corticosteroids have to be administered. Azathioprine, cyclosporin A and metronidazole are considered to be reserve drugs because of significant side effects. The clinical usefulness of new topical corticosteroids showing both high antiinflammatory effect and no systemic side effects is presently investigated.

Spread and distribution of 5-ASA colonic foam and 5-ASA enema in patients with ulcerative colitis

Rectal treatment with enemas, foams, and suppositories is the most efficient method of delivering an adequate quantity of locally active drugs to the distal colon. In a pilot study carried out by colonoscopy in four patients, it was observed that 4 g 5-ASA in 20 ml foam spread up or beyond the splenic flexure and more extensively than 2 g 5-ASA in 10 ml foam. Therefore we have undertaken a study in order to compare by scintigraphy the colonic distribution of 4 g 5-ASA foam versus 4 g 5-ASA in 100 ml liquid enemas in 10 patients with ulcerative colitis using a crossover randomized design. Both preparations were labeled with 100 MBq [99mTc]sulfur colloid before administration. Anterior scans were taken at intervals for 4 hr. Activity, expressed as a percentage of total radioactivity, was measured in the rectum, sigmoid, descending, transverse, and ascending colon. Six patients had the same extent of spread with the two formulations; in three patients with foam and in one patient with enema a greater spread was observed. The foam reached the upper limit of disease in all cases, while enema failed in two cases. The maximum spread with foam was observed within 30 min in nine of 10 patients compared with seven of 10 after enema. Compared to enema, foam distributes more uniformly and seems to persist longer in the descending and sigmoid colon. The 5-ASA colonic foam shows some more favorable characteristics than enema for the local treatment of left-sided ulcerative colitis.

Short-chain fatty acid enemas: a cost-effective alternative in the treatment of nonspecific proctosigmoiditis

The purpose of this study was to perform a randomized, prospective comparison of corticosteroid enemas (CS--100 mg of hydrocortisone/60 cc P.R. q.h.s.; n = 12), mesalamine enemas (5-ASA--4 g/60 cc P.R. q.h.s.; n = 19), and short-chain fatty acid enemas (SCFA--60 cc P.R. b.i.d.; n = 14) for the treatment of proctosigmoiditis. Patients presenting to the Ferguson Clinic with the diagnosis of idiopathic proctosigmoiditis were evaluated for age, sex, prior history of proctitis, duration of symptoms prior to presentation, endoscopic scoring, and mucosal biopsies. Clinical evaluation was performed at two-week intervals for six weeks, with repeat biopsies taken at six weeks. There was no significant difference with respect to age, male/female ratio, past history of proctosigmoiditis, length of colorectum involved at the time of initial presentation, symptom resolution, and endoscopic and histologic improvement among the three treatment groups. Recovery occurred in a similar proportion in each of the three groups: CS, 10/12; 5-ASA, 17/19; and SCFA, 12/14. The cost of six weeks of treatment was: CS, $71.82; 5-ASA, $347.28; and SCFA, $31.50. This study indicates that SCFA enemas are equally efficacious to CS or 5-ASA enemas for the treatment of proctosigmoiditis at a significant cost savings.

Concentrations of 5-ASA and Ac-5-ASA in human ileocolonic biopsy homogenates after oral 5-ASA preparations

Intramucosal 5-aminosalicylic acid (5-ASA) and acetylated 5-ASA (Ac-5-ASA) concentrations were determined in ileocolonic biopsy specimens from 61 patients with irritable bowel syndrome treated for one week with near equimolar doses of different slow release preparations of 5-ASA (Claversal, Asacol, or Pentasa) or azo-bound drugs (Salazopyrin, Dipentum). The transit time in these patients was accelerated by a laxative, metoclopramide, and colonic lavage. The presence of 5-ASA in the mucosa was confirmed by autofluorescence. The highest concentrations of 5-ASA were obtained after Asacol (mean (SEM), 298.5 (37.3) ng/mg wet wt), followed by Claversal 500 mg (108.8 (11.7) ng/mg wet wt) and Pentasa (25.7 (2.2) ng/mg wet wt). Very low concentrations only were observed after Claversal 250 mg (0.3 (0.03) ng/mg wet wt), Salazopyrine (1.2 (0.1) ng/mg wet wt), and Dipentum (11.0 (3.2) ng/mg wet wt). The results for Ac-5-ASA were similar but the concentrations were generally lower. Serum concentration-time curves over eight hours were obtained from 34 healthy volunteers after a single oral dose of 400 to 500 mg of the different drugs. For the slow release forms, an apparently inverse relationship was found between the area under the curve of the serum concentrations and the intramucosal concentrations, supporting the importance of the local availability of the drug. This inverse relationship was absent for the azo-bound drugs. Colonic washout induced mechanical removal of intraluminal 5-ASA with a secondary disturbance in absorption resulting in a rapid decline in the serum concentrations. However, only for Dipentum did this result in significantly lower 5-ASA mucosal concentrations. This is the first reported attempt to evaluate the mucosal availability of 5-ASA after different oral preparations. It shows that where transit time is accelerated higher mucosal concentrations occur after slow release preparations (except for Claversal 250 mg) than after azo-bound drugs. Additional studies are necessary to correlate these concentrations with clinical effects.

[Therapeutic efficacy of 5-ASA molecules in idiopathic intestinal inflammatory diseases: critical review]

Sulfasalazine has been the most widely prescribed drug for patients with inflammatory bowel disease. Clinical trials have established its usefulness in treating patients with active ulcerative colitis and Crohn colitis and its important role in maintaining remissions in patients with ulcerative colitis. Despite its widespread acceptance, the usefulness of sulfasalazine has been limited by the occurrence of adverse reactions in about 10 to 20% of the patients. Now the aminosalicylates are emerging as a treatment for both ulcerative colitis and Crohn disease. We have critically reviewed the clinical trials assessing the efficacy of 5-ASA molecules. Therapeutic efficacy of 5-ASA appears to be as good as sulfasalazine but causing less adverse effects. In mild to moderate ulcerative colitis relapse, 2g 5-ASA is active while 1 g 5-ASA seems equivalent to 2g sulfasalazine for maintaining remission. 5-ASA enema in the treatment of distal ulcerative colitis is helpful and can replace topical cortisone administration. Administration of 1g 5-ASA enema a day seems to be the best regimen. In case of Crohn's disease, preliminary studies are encouraging but more date are required to define the indications as well as the regimen.

Sulfasalazine and 5-ASA compounds

New aminosalicylate formulations have recently been introduced for the treatment of inflammatory bowel disease. Trials in the past decade have convincingly demonstrated their effectiveness in mildly to moderately active ulcerative colitis and in relapse prevention. The rate of side effects was significantly lower with the new aminosalicylates than with conventional sulfasalazine treatment. The therapeutic effects of the new aminosalicylates in Crohn's disease have been less pronounced, and their role in this disease requires further trials.

Calcium alginate beads as core carriers of 5-aminosalicylic acid

The utilization of calcium alginate beads as core carriers for delayed dissolution followed by burst release as a potential method of intestinal site specific drug delivery was investigated. 5-Aminosalicylic acid was spray-coated on dried calcium alginate beads and then coated with different percentages of enteric coating polymer and/or sustained-release polymer. Beads coated with more than 6% (w/w) methacrylic copolymer plastisized with dibutyl sebacate and triethyl citrate resisted release in 2-hr acid fluid challenge and allowed immediate dissolution upon transfer to simulated intestinal fluid. With 6% (w/w) methacrylic copolymer on top of 4% (w/w) ethylcellulose polymer, the major portion of drug did not release in 2 hr of acid treatment or the next 3 hr of simulated intestinal fluid treatment. This dosage form provides the possibility to deliver drug to the lower intestinal tract with minimal early release, followed by sustained release in the colon.

Oral 5-aminosalicylic acid (Asacol) in the maintenance treatment of Crohn's disease

A randomized, placebo-controlled multicenter trial was conducted to evaluate the efficacy and safety of a delayed-release formulation of 5-aminosalicylic acid (5-ASA) (Asacol; Giuliani & Bracco, Milan, Italy) for prevention of clinical relapse in 125 patients with inactive Crohn's disease. Patients in remission [Crohn's Disease Activity Index (CDAI) less than 150] between 3 months and 2 years were randomly allocated to receive either 800 mg 5-ASA three times daily (n = 64) or placebo (n = 61) for up to 12 months or until relapse of symptoms. Relapse was defined by a CDAI greater than 150, with a minimum increase of 100 points over the baseline value. The cumulative relapse rates were 12% in the 5-ASA group and 22% in the placebo group at 3 months [95% confidence interval (CI) for the difference, -4 to 24]; 28% and 41%, respectively, at 6 months (95% CI, -4 to 30); and 34% and 55%, respectively, at 12 months (95% CI, 3-39; P = 0.02, log rank test). Significant decrease in the risk of relapse was found in patients with ileitis, in those with previous bowel resection and, in those with prolonged prestudy remission. Eight patients (5 on 5-ASA, 3 on placebo) withdrew from the study because of adverse reactions, but no major clinical or laboratory adverse effect was observed. It is concluded that oral 5-ASA coated with Eudragit S (Rohn Pharma GmbH, Wieterstadt, Germany), 2.4 g daily, is safe and seems superior to placebo in preventing or delaying clinical relapse in Crohn's disease, especially in milder cases and in ileal disease.