Mesalamine in ulcerative colitis

Sulfasalazine has been used for many years in the management of ulcerative colitis. As many as 20 percent of patients treated with it experience intolerable adverse effects usually attributed to its sulfapyridine component. The other active component is 5-aminosalicylic acid (5-ASA); the only 5-ASA enema preparation currently available in the U.S. is mesalamine (Rowasa, Reid-Rowell) containing 5-ASA 4 g in 60 mL. In clinical trials, mesalamine has proved efficacious in treating refractory cases of distal ulcerative colitis, proctitis, and proctosigmoiditis. Because of its high cost compared with more conventional treatment modalities, it should be reserved for cases that are either refractory or intolerant to conventional treatment.

[Acute alveolitis in ulcerative colitis: extra-intestinal organ complication or drug side effect]

The histories of three possible cases of 5-ASA-induced toxic interstitial lung disease are presented. In addition diagnostical methods and procedures for the differential-diagnosis are discussed and as diagnostical program for the identification of remedy-induced toxic lung-damages is explained.

Pharmacokinetics of a 5-aminosalicylic acid enteric-coated tablet in patients with Crohn's disease or ulcerative colitis and in healthy volunteers

An Eudragit-L coated oral 5-aminosalicylic acid (5-ASA; mesalazine) product (Mesasal), has been formulated to deliver 5-ASA to the distal small bowel and colon for the treatment of inflammatory bowel disease. The purpose of this study was to compare the pharmacokinetic profile of this drug between two patient groups, with either inflamed small or large bowel and with volunteers. Two carefully selected patient groups (one with nine patients suffering from Crohn's disease restricted to the small intestine, and one with ten patients suffering from total ulcerative colitis) and a group of ten volunteers received two 250 mg Mesasal tablets in the morning, on a fasting stomach. Plasma 5-ASA and acetyl-5-ASA concentrations were followed for 48 h, and urine and faecal excretion for 72 h. There was a great variation in most pharmacokinetic parameters within each group. Numerically, however, the data suggests a somewhat higher systemic absorption in patients with Crohn's disease than in healthy volunteers or patients with ulcerative colitis. The location of the inflammatory process might have some influence on the pharmacokinetics of 5-ASA in inflammatory bowel disease.

Topical and systemic availability of 5-aminosalicylate: comparisons of three controlled release preparations in man

The bioavailability of three pure 5-aminosalicylic (5-ASA) preparations (Asacol, Claversal, and Pentasa) was studied in 8 ileostomy patients and 12 normal subjects after 6 days of treatment with 2000 mg 5-ASA. The local bioavailability, reflected by the 5-ASA concentration was thereby measured at two clinically relevant areas of the gut: at the entrance to, and the exit from the colon. Estimates of the systemic bioavailability were obtained from the urinary excretions and the plasma values of 5-ASA and Acetyl-5-ASA (Ac-5-ASA) during the three regimens. The three preparations studied are designed to release 5-ASA at different levels in the intestine, but there was no significant difference in the 5-ASA concentrations in the ileostomy effluents (Asacol 1.8 mmol/L, Claversal 3.4 mmol/L, Pentasa 2.0 mmol/L, median values). However, we found a smaller urinary excretion of 5-ASA and Ac-5-ASA (5.2% vs Claversal 27.9% and Pentasa 23.0%, median values of ingested daily dose) and a lower concentration of Ac-5-ASA in the ileostomy effluents after Asacol treatment (0.8 mmol/L, median value) which indicates a more distal release from this preparation compared with Claversal (2.4 mmol/L, median value) and Pentasa (5.5 mmol/L, median value). In normal subjects a higher faecal water concentration of 5-ASA was found after Asacol (9.8 mmol/L, median value) compared with Claversal (5.0 mmol/L, median value), whereas no difference between the faecal water concentrations of Ac-5-ASA was found (Asacol 21.5 mmol/L, Claversal 21.6 mmol/L, median values). This can be explained by a larger systemic absorption of 5-ASA from Claversal, and accordingly Claversal treatment resulted in the largest urinary excretion of 5-ASA and Ac-5-ASA (43.7% vs Asacol 35.6% and Pentasa 31.6%, median values of ingested daily dose). The high Ac-5-ASA concentration in the ileostomy effluents and in the faeces after Pentasa, and the low plasma values, indicate a slow 5-ASA release from this preparation throughout the small and large intestine. The results of the study indicate that Asacol is released in the distal part of the small intestine, that Pentasa is gradually released in the small and large intestine, and that Claversal shows an intermediate release pattern.

Acute pancreatitis during oral 5-aminosalicylic acid therapy

Therapy with oral 5-aminosalicylic acid for inflammatory bowel disease has been reported as effective and safe. We report two cases of biochemically proven mild acute pancreatitis occurring 2 and 14 days, respectively, after oral 5-aminosalicylic acid therapy was instituted for inflammatory bowel disease. A hypersensitivity mechanism might be involved, owing to possible erratic systemic absorption of the drug. We suggest clinical and biochemical monitoring for patients undergoing oral 5-aminosalicylic acid therapy in order to confirm its possible association with acute pancreatitis and to assess the actual incidence of such an adverse reaction.

5-Aminosalicylic acid suppositories in the maintenance of remission in idiopathic proctitis or proctosigmoiditis: a double-blind placebo-controlled clinical trial

Thirty patients with distal ulcerative colitis in remission (17 proctitis, 13 proctosigmoiditis) were randomly given either 5-aminosalicylic acid (5-ASA) or placebo suppositories, 400 mg bid. During the 1-yr follow-up, patients were assessed clinically every month, and flexible sigmoidoscopy with a rectal pinch biopsy specimen and laboratory data were carried out every 3 months. Two patients in the 5-ASA group chose to withdraw from the study, one relapsed, and 12 remained in remission. In the placebo group, one patient chose to withdraw, 11 relapsed, and three remained in remission. The cumulative remission rate at the 12th month was 92% in the 5-ASA group and 21% in the placebo group. Log rank test showed a significant difference in the relapse rate between the two groups (chi 2 = 14.26, p less than 0.001). No side effects were observed. We conclude that 5-ASA in suppository form (800 mg/day), administered for 1 yr, is safe and effective in maintaining remission of distal ulcerative colitis.

Long-term use of mesalamine enemas to induce remission in ulcerative colitis

The courses of 90 patients with left-sided ulcerative colitis that was unresponsive or intolerant to conventional therapy were retrospectively reviewed. They had been treated with 5-aminosalicylic acid enemas (mesalamine) on a long-term basis. After an initial 12-week course of treatment, 87% of the patients had improved by at least one grade of inflammation (improvement), and 54% of these were asymptomatic with normal colonic mucosa (remission). Overall, there was an 80% remission rate by 34 weeks. Remission rate was not affected by extent of sigmoid or left-sided colon disease before treatment or prior medication use for ulcerative colitis. Treatment with mesalamine enemas allowed patients to decrease or discontinue glucocorticoid treatment. Patients treated for relapse episodes responded as well as they did to the first course of treatment, whether the relapse occurred after discontinuation of mesalamine or during a tapering of the dose. In conclusion, extending mesalamine treatment to at least 34 weeks was beneficial in inducing a complete remission in 80% of patients unresponsive to conventional therapy.

Effect of food coadministration on 5-aminosalicylic acid oral suspension bioavailability

Single doses of 1 gm 5-aminosalicylic acid (5-ASA) suspension was administered to 24 healthy volunteers during both fasting and fed conditions. For subjects in a fasting state, plasma 5-ASA and acetyl 5-ASA concentrations peaked rapidly 1 hour after dosing to 14.72 micrograms/ml and 11.4 micrograms/ml, respectively. The elimination half-life of 5-ASA was 51.9 minutes, whereas the acetyl 5-ASA half-life could not be determined. A mean of 78.3% of the dose was excreted in the urine, with 5-ASA accounting for 21.2% of the dose and acetyl 5-ASA accounting for the balance. Only 11.3% of the dose was eliminated in the feces, consisting mostly of acetyl 5-ASA. Food coadministration reduced 5-ASA and acetyl 5-ASA systemic relative bioavailability to 44% and 76%, respectively, compared with the fasting treatment. Urinary excretion of the salicylates was reduced to 46.8%, and fecal salicylate elimination increased almost 100%--to 24.2% of the total dose.

Mesalazine (5-aminosalicylic acid) suppositories in the treatment of ulcerative proctitis or distal proctosigmoiditis. A randomized controlled trial

A multicentre double-blind study was conducted to evaluate the efficacy and tolerability of 1 g or 1.5 g mesalazine daily compared with placebo in 94 patients with mild to moderate distal proctosigmoiditis (less than 20 cm). The study end point was the determination of clinical, endoscopic, and histologic remission rates at 4 weeks. Eleven patients, nine receiving placebo and two receiving 1.5 g mesalazine, withdrew during trial, mostly because of worsening of symptoms. At 4 weeks clinical remission was achieved in 7 of 31 (39%) patients with placebo, in 22 of 32 (69%) patients in the 1 g mesalazine group, and 23 of 31 (74%) patients in the 1.5 g mesalazine group. No serious clinical or biochemical side effect of treatment was reported. Mesalazine suppositories are safe, well tolerated, and very effective in patients with active distal proctosigmoiditis: 500 mg twice daily appears a suitable dose regimen.

Absorption of oral mesalazine-containing preparations and the influence of famotidine on the absorption

The mesalazine-containing preparations Asacol, Pentasa, and Salofalk (=Claversal) are frequently used in the treatment of inflammatory bowel disease. The release patterns of these formulations are time- and/or pH-dependent. The aim of this study was to investigate the patterns of absorption of these preparations and the influence of raised intragastric pH on absorption. Gastric pH was raised by simultaneous administration of famotidine. Absorption was determined by assaying with a high-performance liquid chromatography method the urinary excretion of acetylmesalazine, the major metabolite of mesalazine. A large intra- and inter-individual variability in absorption was found for all three formulations, both with and without concomitant famotidine administration. Asacol and Pentasa were significantly less absorbed than Salofalk. A significant lower absorption of mesalazine was seen when Asacol was combined with famotidine. Variations in gastric pH have negligible effect on the bioavailability of mesalazine in vivo.

Intermittent therapy with high-dose 5-aminosalicylic acid enemas for maintaining remission in ulcerative proctosigmoiditis

Sixty patients who had presented recently with a relapse of mild to moderate ulcerative colitis with rectosigmoid involvement were randomly assigned to treatment with either 5-aminosalicylic acid enemas (N = 29) or oral sulfasalazine (N = 31). All patients were in remission, which was documented by clinical, histologic, and endoscopic criteria. Five-aminosalicylic acid treatment was administered on an intermittent schedule, consisting of 4 gm daily for the first seven days of each month; sulfasalazine was given as continuous therapy (2 gm daily as oral tablets). The study period was 2 years. Overall, 9 relapses occurred in the 5-aminosalicylic acid group and 12 occurred in the sulfasalazine group. The actuarial relapse rate at 12 months was 20 percent in the 5-aminosalicylic acid group and 24 percent in the sulfasalazine group; at 24 months, these rates were 37 and 43 percent, respectively. The actuarial relapse curves of the two groups were very similar. The relapse severity was also similar between the two groups. These results show that the authors proposed schedule of maintenance treatment with high-dose 5-aminosalicylic acid enemas is effective in subjects with rectosigmoiditis. This form of intermittent therapy may therefore be proposed for maintaining remission in patients who are refractory to oral and/or rectal treatment with sulfasalazine and steroids or who are intolerant or allergic to sulfasalazine. Treatment with 5-aminosalicylic acid enemas for seven days each month can also constitute an alternative for patients who favor the intermittent schedule over the classic continuous regimen of oral administrations.

Topical treatment with 5-aminosalicylic in distal ulcerative colitis by using a new suppository preparation. A double-blind placebo controlled trial

Sixty-two patients with ulcerative colitis localised to the distal sigmoid colon and rectum (less than 20 cm) entered the trial. Thirty-two were treated with 5-ASA 500 mg suppositories (Asacol) 3 times a day for 1 month while 30 received a placebo given in the same regime. Clinical, sigmoidoscopic and histological assessment was carried out before, after 15 days and after 1 month of treatment. At the end of the study 5-ASA suppositories showed significantly better results in all the parameters recorded than placebo (p less than 0.01). There were no unwanted effects related to the use of suppositories. This treatment should therefore be offered as a first choice for patients with distal rectosigmoiditis.

Pancreatitis after rectal administration of 5-aminosalicylic acid

A patient treated with sulfasalazine for new-onset ulcerative colitis developed self-limited pancreatitis. Rechallenge with 5-aminosalicylic acid (5-ASA) in enema form (Rowasa) again induced pancreatitis. Recent case reports suggest that the salicylate component of sulfasalazine can lead to the development of pancreatitis with oral 5-ASA administration. This patient's course demonstrates further that rechallenge with 5-ASA in a rectal form may also lead to pancreatitis.

Coated oral 5-aminosalicylic acid versus placebo in maintaining remission of inactive Crohn's disease. International Mesalazine Study Group

A randomized, double-blind, placebo-controlled multicentre study was undertaken to evaluate the safety and efficacy of coated, oral 5-aminosalicylic acid (Mesasal/Claversal; 5-ASA) in maintaining remission of inactive Crohn's disease for up to 12 months. A total of 248 patients were entered from eight countries, of which 206 adhered to the protocol and were included in the analysis. The patients had Crohn's disease for an average of 5 years, with their disease clinically inactive for at least 1 month prior to entry into the study, and for an average of over 12 months previously. Thirty per cent of patients had had a previous resection, 16% of patients had been treated with sulphasalazine, while none of those analysed received glucocorticosteroids. Treatment consisted of 500 mg 5-ASA t.d.s. or placebo. 'Relapse' was defined as the first occurrence of Best's Crohn's Disease Activity Index greater than 150, which had increased 60 points from the pre-trial index. The cumulative life-table relapse estimate was lower in 5-ASA patients compared to placebo (22.4% vs 36.2%, respectively, Log rank test P = 0.0395). The 12-month relapse estimate in the 5-ASA group was also lower in patients with ileal disease (8.3% for 5-ASA and 31.0% for placebo, P = 0.0535) and in patients with previous bowel resections (14.2% vs 47.0%, P = 0.0436). The incidence of side-effects was similar in both treatment groups. It is concluded that 5-ASA was significantly superior to placebo in preventing relapse of Crohn's disease; this effect was most apparent in patients with disease restricted to the ileum and in patients with previous bowel resection. 5-ASA was well-tolerated, as demonstrated by a low incidence of adverse events.

[Efficacy and tolerability of 5-aminosalicylic acid in the short-term treatment of ulcerative rectocolitis during the mild or moderate stage]

The aim of the study was to compare the efficacy and side-effects of 5-ASA and SASP in the treatment of active ulcerative colitis. An improvement was seen in 71.4% (5-ASA) and 70.3% (SASP) but there were no complete remissions. The incidence of improvements was only 36.3% (5-ASA) and 37.5% (SASP) in pancolitis. The side-effects appeared in 14.2% (5-ASA) and 21% (SASP).

Advances in drug therapy for inflammatory bowel disease

PURPOSE

To identify advances in drug therapy for inflammatory bowel disease, and to evaluate the effectiveness of the new agents in treating both ulcerative colitis and Crohn disease.

DATA IDENTIFICATION

Studies published from January 1980 through June 1989 were identified using MEDLINE and through extensive hand searching of bibliographies in identified articles.

STUDY SELECTION

One hundred and ten articles directly related to the topic were found and analyzed. Another 42 articles were relevant to the material reviewed.

DATA EXTRACTION

Articles were selected on the basis of study quality and their significance with regard to treatment of inflammatory bowel disease.

RESULTS OF DATA ANALYSIS

The aminosalicylates are emerging as effective and safe therapy for inflammatory bowel disease. Corticotropin can be considered the drug of choice for certain patients with severe ulcerative colitis, and new rapidly metabolized topical steroids appear to be as effective as traditional forms and have fewer side effects. Immunosuppressive agents, including 6-mercaptopurine and azathioprine, may be useful in treating difficult-to-manage patients with either Crohn disease or ulcerative colitis, whereas cyclosporine appears promising but should be reserved for patients in whom other measures have failed. Patients with refractory perineal Crohn disease and those with Crohn colitis may benefit from metronidazole. Many other drugs including clonidine, cromoglycate, chloroquine, fish oil, methotrexate, antituberculous agents, interferon, and superoxide dismutase have shown enough promise in preliminary studies to warrant controlled clinical trials.

CONCLUSIONS

Drug therapy for inflammatory bowel disease, limited for many years to sulfasalazine and some corticosteroids, has been extended to include the aminosalicylates, rapidly metabolized topical steroids, immunosuppressive agents, and metronidazole. Potentially useful newer drugs await further study.

Role of rectal formulations: suppositories

Mesalazine (5-aminosalicylic acid) suppositories are safe, effective, well tolerated, and well retained in patients with active distal proctitis. The best results are seen in patients with idiopathic ulcerative proctitis. Approximately 85% of these patients are healed within 4 weeks and virtually 100% by 10 weeks, with mucosal healing and complete loss of symptoms. Suppositories cover the last 20 cm of the rectum, as shown by technetium labelling. Maintenance therapy using suppositories alone--in doses varying from 500 mg every second bedtime to 1000 mg per day in divided doses--is at least as effective as oral sulphasalazine. Mesalazine suppositories are also useful in treating patients with Crohn's disease affecting the rectum, although the response rate is slower and healing is incomplete in half the patients treated. In the rare solitary rectal ulcer syndrome, mesalazine suppositories may be as efficacious as mesalazine enemas. Patient compliance and dramatic response even when conventional therapy has failed make an excellent case for mesalazine suppositories being the treatment of choice for distal ulcerative proctocolitis.

Role of rectal formulations: enemas

Clinical experience with mesalazine enemas in the treatment of ulcerative colitis is reviewed. After rectal administration, plasma mesalazine levels remain low, and 15% of the administered dose is recovered in the urine. Enemas containing 2 and 4 g of mesalazine have been shown to be effective, safe, and well tolerated by patients with mild and moderate ulcerative colitis. Patients who cannot tolerate sulfasalazine and patients who do not respond to other treatments have been successfully treated with mesalazine enemas. Suppositories of mesalazine are more suitable for patients with disease confined to the distal region of the colon, whereas mesalazine enemas should be used in patients with more extensive disease. Mesalazine enemas have also been used for maintenance therapy in ulcerative colitis.

Topical treatment of ulcerative colitis

It is clear that the therapeutic options available for the treatment of ulcerative proctosigmoiditis have increased over the last few years and in the future additional therapies will be available. Therapy will have to be individualized. Studies to date have generally failed to confirm the superiority of one form of treatment over another, although there is some evidence that high-dose 5-ASA enemas are superior to hydrocortisone enemas. Patients who fail to respond to one form of therapy may respond to another therapeutic modality. Continued evaluation of topical therapies provides not only an opportunity to improve the treatment prospects for patients but also allows for examination of potential mechanisms of action of therapeutically active compounds. Future research directions should also include assessment of combination therapy, the more widespread use of suppositories, and strategies to encourage patient compliance. Larger multicenter trials are needed to assess the effectiveness of some of the newer compounds. The role of topical therapy for patients with Crohn's disease confined to the left colon requires evaluation.

Mesalazine in childhood inflammatory bowel disease

A study was undertaken in paediatric patients suffering from ulcerative, Crohn's or indeterminate colitis. This aimed to compare the occurrence and tolerance of side-effects arising during treatment with position-release mesalazine (Asacol) with those occurring during previous treatment with sulphasalazine (Salazopyrin). The drugs were used to maintain remission from colitis. The occurrence of adverse reactions was also monitored. Sixty-seven children were assessed for a period of 6 months; 45 of these children received mesalazine after previous treatment with sulphasalazine. The results show that the majority of patients were maintained in remission with either drug, but they reported a preference for position-release mesalazine with respect to ease and frequency of administration when compared to sulphasalazine. No serious adverse reactions arose during mesalazine treatment, compared with three such events during previous sulphasalazine treatment.

Disposition of 5-aminosalicylic acid from 5-aminosalicylic acid-delivering drugs during accelerated intestinal transit in healthy volunteers

In eight healthy volunteers accelerated intestinal transit time was induced with bisacodyl, and urinary and faecal excretion of sulphasalazine, olsalazine, 5-aminosalicylic acid (5-ASA), and acetyl-5-ASA was studied after a single oral dose of 3.3 mmol sulphasalazine, olsalazine, Pentasa, and Salofalk and 2.6 mmol of Asacol. The faecal and urinary excretion of acetyl-5-ASA was lowest after intake of sulphasalazine and olsalazine and highest after intake of Pentasa and Salofalk. The figures for Asacol were intermediate. This indicates insufficient release of 5-ASA from sulphasalazine and olsalazine. When the results of this study are compared with those of a previous study without accelerated transit time, the disposition of 5-ASA from all the 5-ASA-delivering drugs is influenced unfavourably by an accelerated gut transit but most pronounced in the case of sulphasalazine, olsalazine, and Asacol. The impaired release from the azo compounds sulphasalazine and olsalazine is a result of far less complete splitting of the diazo bond.