Use of mesalazine slow release suppositories 1 g three times per week to maintain remission of ulcerative proctitis: a randomised double blind placebo controlled multicentre study

Oral mesalazine (5-ASA) treatment may protect against proximal extension of mucosal inflammation in ulcerative proctitis

OBJECTIVES

Studies aimed at establishing which characteristics of patients with ulcerative proctitis could be predictive of the extension of inflammation have failed to provide conclusive results. The aim of the study was to evaluate the prognostic role of clinical and therapeutic parameters in patients with proctitis.

PATIENTS AND METHODS

Case records of 138 patients with ulcerative proctitis were retrospectively evaluated. The following parameters were considered: gender; age at onset of disease; smoking habits; histologic severity of disease at onset; mean number of clinical relapses of disease per year; mean duration of oral and topical mesalazine treatment; and number of topical corticosteroid treatments per year.

RESULTS

Twenty-eight patients were excluded from the analysis for different reasons. During follow-up, inflammation spread proximally in 33 of 110 patients (30%). Patients with extended proctitis showed a significantly higher number of relapses and a shorter duration of oral mesalazine treatment than patients with nonprogressive proctitis (p < 0.001 for both). The multivariate analysis also found that the mean duration of topical mesalazine treatment was longer in patients with extended proctitis.

CONCLUSIONS

Ulcerative proctitis patients with more frequent relapses who need a longer duration of topical therapy are at higher risk of extension of the disease, while a more prolonged oral mesalazine treatment period protects against the proximal spread of rectal inflammation.

Diagnosis and treatment of ulcerative proctitis

Proctitis refers to inflammation of the rectum, a diagnosis made by endoscopic evaluation. Symptoms of proctitis include rectal bleeding, urgency, tenesmus, diarrhea or constipation, and occasionally rectal pain. The causes of proctitis include infection, medication, ischemia, radiation, and ulcerative proctitis. Ulcerative proctitis is an important and increasingly common subcategory of ulcerative colitis (UC) in which inflammation is limited to the rectum. Historically, oral aminosalicylates have been the mainstay of acute and maintenance therapy. A growing body of data, however, indicates that topical aminosalicylates are effective first line agents in ulcerative proctitis and distal UC. Topical aminosalicylates act more effectively and rapidly to induce and maintain remission compared with their oral counterparts or topical steroids. Rarely ulcerative proctitis is refractory to topical therapy and in these instances systemic corticosteroids, antibiotics, immunomodulators, or surgery is required. This review highlights the pathogenesis, diagnosis, and treatment of ulcerative proctitis.

Management of inflammatory bowel disease

Ulcerative colitis and Crohn's disease result from an interaction between genetic and environmental factors. Only one gene, NOD2/CARD15, has been clearly identified; a minority of people with alteration of this gene develop Crohn's disease. The NOD2/CARD15 protein is thought to be involved in defence against intracellular bacteria. This supports the idea that Crohn's disease and ulcerative colitis result from altered immunological responses to the normal intestinal flora. Life expectancy is normal in ulcerative colitis and nearly so in Crohn's disease, but both conditions cause considerable morbidity. Approximately 80% of patients with Crohn's disease eventually require surgery, and about 25% of patients with ulcerative colitis require colectomy. Treatment of ulcerative colitis is generally by corticosteroids for acute disease and mesalazine for maintenance, but the range of therapies for Crohn's disease is expanding. Alternative therapies include immunosuppressives, enteral nutrition, antibiotics, anti-TNF antibody (infliximab), corticosteroids, and surgery. High dosages of corticosteroids may provide symptomatic relief in Crohn's disease but do not affect the long term natural history of the disease, and management strategies should avoid using steroids whenever possible.

Role of mesalazine in acute and long-term treatment of ulcerative colitis and its complications

BACKGROUND

Sulfasalazine, consisting of 5-aminosalicylic acid bound to sulfapyridine by a diazo bond, was first used for treatment of ulcerative colitis in the early 1940s and later found effective in placebo-controlled trials for acute disease and for long-term maintenance of remission. Later studies found that the active moiety is 5-ASA (mesalazine, mesalamine) and the sulfapyridine moiety acts as a carrier molecule but causes many of the symptomatic adverse reactions.

METHODS

Review of the literature.

RESULTS

The finding that 5-ASA in the active motility led to the development of mesalazine prodrugs, olsalazine (Dipentum) and balsalazide (Colazide, Colazal), and targeted release mesalazine preparations, such as Asacol, Pentasa, and Salofalk, as well as enemas and suppository preparations for distal disease. Most patients with adverse effects from sulfasalazine will tolerate mesalazine. Mesalazine has been shown equivalent or superior to sulfasalazine, and superior to placebo, with a dose-response benefit, in inducing remission of acute disease. and comparable to sulfasalazine and superior to placebo for long-term maintenance of remission. Better tolerance of mesalazine and the ability to use higher doses favor its use in patients intolerant of sulfasalazine and in patients failing to respond to usual doses of sulfasalazine. Adverse effects from mesalazine are uncommon, but include idiosyncratic worsening of the colitis symptoms and renal toxicity. Mesalazine is safe to use during pregnancy and for nursing mothers. As maintenance therapy, mesalazine may reduce the risk of developing colorectal carcinoma.

CONCLUSION

Mesalazine represents effective and well-tolerated first-line therapy for mildly to moderately acute disease as well as for the long-term maintenance treatment in the patient with ulcerative colitis.

Review article: maintenance of remission in ulcerative colitis

Seventy percent of patients with ulcerative colitis can expect to experience a relapse over a 12 month period. Sulfasalazine was the first drug demonstrated to reduce this relapse rate to 21 percent. Subsequent studies have demonstrated that 5-aminosalicylic acid (5-ASA) is the main active component, and preparations containing only 5-ASA have similar efficacy to sulfasalazine. 5-ASA is readily absorbed from the small intestine; to achieve high a colonic lumenal concentration therefore requires special release formulation. A variety of 5-ASA preparations is available, differing in their release mechanism, efficacy and side effect profile. Most patients can be maintained in remission using oral 5-ASA medication. For patients with distal or left sided disease the use of rectal 5-ASA is also of proven benefit in maintaining remission. Some patients with frequent or severe relapses require stronger immunosuppression, and in these patients azathioprine or 6-mercaptopurine (6-MP) are of proven benefit. Azathioprine is also invaluable for maintaining remission in patients who have been treated with cyclosporin for a fulminant acute episode of colitis. The exciting spectre of natural bacterial therapies (probiotics) deserves further exploration.

5-amino-salicylate in the management of inflammatory bowel disease

The role of aminosalicylates in the treatment of idiopathic bowel disease is reviewed, with emphasis on how the different formulations can be used in different clinical manifestations. Although not fully understood, the possible mechanisms of action of these agents are discussed and their adverse reactions noted. Their use in clinical practice, both in acute disease and in remission, is outlined with particular reference to the different delivery characteristics of the aminosalicylates, thus allowing their use according to the distribution of the disease. Finally, benefits that might come from maintenance therapy, including possible reduction in post-operative recurrence of Crohn's disease and the risk of colorectal cancer are mentioned.

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 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.

Putting rectal 5-aminosalicylic acid in its place: the role in distal ulcerative colitis

Oral aminosalicylates such as sulfasalazine and mesalamine are widely prescribed for the treatment of mild or moderately active distal ulcerative colitis. However, a critical review of the literature demonstrates that rectal 5-aminosalicylic acid (5-ASA) is the optimal therapy for this disease. Meta-analyses of published trials show that rectally delivered 5-ASA is superior to placebo and to conventional rectal corticosteroids in inducing remission of distal ulcerative colitis, whereas the combination of rectal 5-ASA with a rectal corticosteroid or oral aminosalicylate is superior to rectal 5-ASA alone. For maintaining remission of distal ulcerative colitis, rectal 5-ASA is significantly better than placebo and at least as effective as oral 5-ASA. The dosage forms available for rectal delivery include suppositories, foams, and liquid enemas, and selection among these preparations should be guided by the proximal extent of disease and patient preference. The efficacy of rectal 5-ASA is complemented by its low rate of reported adverse effects, which may reflect its reduced potential for systemic absorption. This review summarizes the evidence supporting the role of rectal 5-ASA as a first-line therapy for mild or moderately active distal ulcerative colitis, and offers guidelines for its use.