Therapeutic benefits from a poorly absorbed prednisolone enema in distal colitis

Glucocorticosteroids in the treatment of inflammatory bowel disease and approaches to minimizing systemic activity

Inflammatory bowel diseases (IBDs) are a group of inflammatory conditions characterized by chronic, uncontrolled inflammation of the gastrointestinal tract. Reported prevalence is high in the United States and northern Europe, while the incidence varies greatly across the rest of Europe. Glucocorticosteroids are the standard treatment for IBD, but due to adverse events their use can be limited. However, new formulations of glucocorticosteroids have been developed to reduce systemic activation. The aim of this review was to assess and summarize the efficacy and safety of new formulations of glucocorticosteroids. A MEDLINE search identified publications focused on new formulations of nonsystemic steroid-based drugs for IBD and benefits and limitations of each of the new glucocorticosteroid formulations were identified. Budesonide has good efficacy and is an established treatment for Crohn's disease; it has been shown to be beneficial for the induction of remission in these patients, although it is not recommended for the maintenance of induced remission. Glucocorticosteroids are not recommended for the maintenance of remission in patients with IBD. However, a recent study suggested that beclomethasone dipropionate may be effective for prolonged treatment in patients in the postacute phase of Crohn's disease who were treated with a short course of systemic steroids. The efficacy of fluticasone propionate and prednisolone metasulphobenzoate in IBD is not well established given the small number of patients enrolled in the few published clinical trials. While the tolerability of these glucocorticosteroids is favourable, more research comparing these new agents with traditional systemic glucocorticosteroids is warranted.

Optimization of conventional therapy in patients with IBD

The majority of patients with IBD use conventional therapy (namely, aminosalicylates, antibiotics, corticosteroids and immunomodulatory agents) for prolonged periods of time, to both induce and maintain remission. Treatment paradigms in IBD have evolved towards a rapid escalation of therapy to achieve stringent goals, including mucosal healing and a reduction in the need for hospital admission and surgery. In this context, the failure to optimize conventional therapy can lead to a potentially effective treatment being abandoned too early, which is undesirable when only a limited number of drugs are effective in the management of IBD, and could also lead to patients being unnecessarily exposed to potentially toxic and/or expensive biologic drugs. This Review provides an overview of the many ways in which conventional therapy can be optimized, and describes strategies to improve adherence to drug regimens, such as simplifying the dosing regimen, optimizing drug delivery and dose, and tailoring medication on the basis of metabolite levels.

Therapeutic effects of rectal administration of muscovite on experimental colitis in rats

BACKGROUND AND AIMS

The aim of this study was to investigate whether rectal administration of muscovite can ameliorate colonic inflammation in a rat model of experimental colitis, and its possible mechanism.

METHODS

Female Sprague-Dawley (SD) rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis were treated with rectal administration of muscovite or 5-aminosalicylic acid (5-ASA) daily for 14 days. The changes in body weight, macroscopic damage and histologic scores were subsequently evaluated. Gene expression of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), mucin2 (MUC2) and trefoil factor 3 (TFF3) in the colonic tissues was assessed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR) while protein levels of TNF-alpha and IL-1beta were detected by ELISA. Mucin2 expression in colonic mucosa was detected by immunohistochemistry. The capacity of muscovite to adsorb cytokines in vitro was determined by the changes in the amount of TNF-alpha, IL-1beta secreted by lipopolysaccharide (LPS)-stimulated THP-1 cells and IL-8 secreted by LPS-stimulated HT-29 cells.

RESULTS

Rectal administration of muscovite improved the loss of body weight, macroscopic and histologic scores of TNBS-induced colitis in a dose-dependent manner. Trinitrobenzene sulfonic acid-induced expression of TNF-alpha and IL-1beta was reduced by muscovite and 5-ASA treatment. Reduction of MUC2 expression in colitis rats was reversed by muscovite and 5-ASA treatment. However, the expression of TFF3 mRNA in colonic mucosa was not affected. In addition, we found muscovite inhibited the expression of TNF-alpha, IL-1beta secreted by THP-1 and IL-8 secreted by HT-29 cells in a dose-dependent manner.

CONCLUSIONS

Our study demonstrated for the first time that rectal administration of muscovite can ameliorate colonic inflammation of TNBS-induced colitis. Further confirmatory studies are needed to prove that muscovite might be a potential therapeutic agent for the treatment of ulcerative colitis.

Clinical trial: oral prednisolone metasulfobenzoate (Predocol) vs. oral prednisolone for active ulcerative colitis

BACKGROUND

Systemic corticosteroids are effective in ulcerative colitis but commonly cause side effects.

AIM

To compare the safety and efficacy of a sparingly absorbed formulation of prednisolone metasulfobenzoate (Predocol) with a conventional tapering course of oral prednisolone.

METHOD

In a double-blind randomized study, 59 active ulcerative colitis patients received Predocol 40 mg/day for 6 months, 61 received Predocol 60 mg/day for 6 months and 61 received prednisolone 40 mg/day for 2 weeks, tapered to week 8, followed by placebo until 6 months.

RESULTS

Steroid-related side effects assessed using a 10-cm visual analogue scale were fewer at 2 months with Predocol 40 mg [VAS 8.1 cm (2.6), mean (s.d.)], or 60 mg [8.1 (2.1)] compared with prednisolone [6.7 (2.7); P = 0.01]. Mood changes affected 43% receiving prednisolone at 4 weeks vs. 8% for Predocol 40 mg (P = 0.001). Remission rates (Powell-Tuck < or =2) at 2 months were Predocol 40 mg 46%, Predocol 60 mg 28% and tapering prednisolone 41% (P = 0.13). Visual analogue scale for efficacy also showed non-inferiority for Predocol 40 mg/day. Remission rates at 6 months were Predocol 40 mg 51%, Predocol 60 mg 38% and tapering prednisolone 32% (P = 0.08).

CONCLUSION

Predocol 40 mg/day has similar efficacy but markedly fewer side effects than a conventional tapering prednisolone regimen (ISRCTN14133410).

Novel drug delivery strategies for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) encompasses two idiopathic inflammatory diseases of the intestinal tract: Crohn's disease and ulcerative colitis. Existing therapy for IBD consists mainly of orally or rectally administered small drug molecules, such as 5-aminosalicylates and corticosteroids, or potent systemic immune suppressants. IBD presents a challenging target for drug delivery, particularly by the oral route, as, contrary to most therapeutic regimens, minimal systemic absorption and maximal intestinal wall drug levels are desired. Several delivery strategies are employed to achieve this goal, including the chemical modification of the drug molecules, the use of controlled- and delayed-release formulations and the use of bioadhesive particles. The goal of this review is to summarise existing IBD therapy and examine novel approaches in intestinal drug delivery.

Comparative tolerability of therapies for ulcerative colitis

This article reviews the clinical pharmacology, adverse events, and comparative tolerability of the drugs commonly available for treating ulcerative colitis. Synthetic glucocorticoids are the most commonly used conventional corticosteroids in the treatment of ulcerative colitis. Corticosteroids can be expected to impact on every organ system and most metabolic activities of the body. Suppression of the hypothalamic-pituitary-adrenal axis is common, but reversible, with conventional corticosteroids, but not with newer topically-acting corticosteroids. A serious complication of corticosteroids in children is growth retardation. The frequent adverse effects associated with the use of corticosteroids have prompted the development of a new group of rectal agents with equivalent efficacy and a more benign adverse event profile such as prednisolone metasulfobenzoate, fluticasone propionate, tixocortol pivalate, beclomethasone dipropionate and budesonide. The incidence of adverse effects related to the use of sulfasalazine (5-aminosalicylic acid plus sulfapyridine) is high and is dose related. The most frequently reported adverse effect is intolerance, not allergy, and relates to the sulfapyridine moiety correlating with the acetylator phenotype. Tolerance to 5-aminosalicylic acid by 80 to 90% of those patients allergic to, or intolerant of, sulfasalazine has given further evidence suggesting that the sulfa moiety is responsible for much of the toxicity of sulfasalazine. However, 10 to 20% of patients who are sulfasalazine intolerant have similar reactions to 5-aminosalicylic acid formulations, indicating that the 5-aminosalicylic acid moiety is responsible for adverse events in some patients taking sulfasalazine. Adverse effects resulting from treatment with azathioprine and mercaptopurine can be divided into two categories: allergic-type reactions that appear to be dose-independent and nonallergic-type reactions that are probably dose- and metabolism-dependent. It is well established now that genotype and thiopurine methyltransferase activity have an important impact on the rate of adverse effects during azathioprine or mercaptopurine therapy. Adverse effects resulting from high dose cyclosporin therapy for inflammatory bowel disease include: renal insufficiency, hypertension, opportunistic infections, seizures, paresthesias, tremor, headache, gingival hyperplasia, hypertrichosis, and anaphylaxis with intravenous cyclosporin. In contrast, the incidence of adverse events was relatively low when low-dose oral cyclosporin was used. The incidence of adverse events associated with any of the medications used in the treatment of ulcerative colitis is difficult to assess and it is therefore hard to make a comparative evaluation. The broadening of the drug regimen available to the clinician has advanced our knowledge about the disease, and further development of more effective, less toxic agents can be anticipated in the future.

Medical management of inflammatory bowel disease in the new millennium

The medical management of inflammatory bowel disease in the new millennium requires integrating cost concerns with the efficacy and safety profiles of the expanded therapeutic options available in order to achieve optimal patient outcome.

Pharmacokinetics and pharmacodynamics of dexamethasone sodium-m-sulfobenzoate (DS) after intravenous and intramuscular administration: a comparison with dexamethasone phosphate (DP)

The pharmacokinetics (PK) and pharmacodynamics (effects on blood lymphocytes) of dexamethasone (D) after intravenous (i.v.) administration of dexamethasone phosphate (DP, 10 mg, equivalent to 8.3 mg of dexamethasone) and after intravenous and intramuscular (i.m.) administration of dexamethasone sulfobenzoate sodium (DS, 9.15 mg, equivalent to 6 mg of dexamethasone) were assessed. Only 25% of DS was converted into dexamethasone with a half-life for DS of 5.4 hours and 7.4 hours after i.v. and i.m. administration, respectively. Consequently, the mean residence time of D after both i.m. and i.v. administration of DS (10.4-11.6 h) was longer than that after DP administration (6.1 h). The smaller lymphocyte suppression induced by DS (50% of that after DP administration) was shown to be related to differences in the pharmacokinetics. This study revealed significant differences in the pharmacokinetics of D after administration of DS and DP and stresses the importance of the prodrug for the pharmacological response. Because of the slow and incomplete conversion of DS into dexamethasone, its use in emergency medicine situations should be critically evaluated.

Restorative proctocolectomy for distal proctocolitis

BACKGROUND

Restorative proctocolectomy (RP) is usually the surgical treatment of choice for severe ulcerative colitis, but patients with distal disease (rectosigmoid only) are frequently denied operation on the grounds that they are not systemically ill. Nevertheless, they may continue to have high frequency, low volume diarrhoea with severe urgency and bleeding, despite medical therapy.

OBJECTIVE

To report the outcome of RP in `distal disease' compared with `more extensive' disease.

PATIENTS AND METHODS

The results of all patients having RP for ulcerative colitis between February 1983 and February 1997 were reviewed. We excluded patients later found to have Crohn's disease.

RESULTS

RP was used for 34 with `distal' disease compared with 134 with `more extensive' disease. Pre-operative steroids were used in 9% of the `distal' group compared with 34% in the `more extensive' group. Anastomotic leaks and pelvic sepsis occurred in 3% and 9%, respectively, in the `distal' group compared with 13% and 17% in the `more extensive' group, but these differences were not statistically significant. Pre-operative steroids significantly influenced anastomotic leaks 22% vs 5% (P = 0.006). Pouch-related fistulas occurred in 12% of the `distal' group compared with 15% in the remainder. Pouchitis occurred in 44% of the `distal' group: 44% compared with 33% in the remainder. Pouch failure occurred in 3% in `distal' compared with 15% in those with `more extensive' disease.

CONCLUSION

These results imply that RP has a role in the treatment of intractable `distal' colitis, that morbidity is low and urgency is usually eliminated.

The gastrointestinal passage and release of beclomethasone dipropionate from oral delivery systems in ileostomy volunteers

AIMS

To study the delivery of 15 mg beclomethasone 17,21-dipropionate (BDP) to the distal part of the small bowel for three oral sustained-release formulations (I-III) and a reference capsule in volunteer ileostomists, and to compare these findings with the in vitro dissolution profiles.

METHODS

Two groups of nine ileostomy volunteers (aged 20-61 years), who were otherwise healthy, were enrolled in the study. The recovery of BDP and its metabolite beclomethasone 17-monopropionate (B17P) in ileostomy effluent was investigated in a cross-over study after administration of formulations I or II or a reference capsule containing micronised BDP, and in a second open study after administration of formulation III. Radio-opaque granules were coadministered for evaluation of gastrointestinal passage. Ileostomy effluents were collected hourly for 10-12 h following drug intake. After marker beads had been counted on X-rays, ileostomy collections were analysed for BDP and its metabolites. Cumulative recovery, lag-time and mean transit time were determined for drug and marker beads.

RESULTS

Gastrointestinal passage characteristics were similar for all treatments. Total drug recovery was approximately three times higher for the sustained-release formulations than for the reference capsule. Recovery of B17P from stoma fluid samples was significantly lower for formulation III than for formulations I and II.

CONCLUSIONS

The novel oral formulations delivered substantial amounts of steroid drug at the distal small bowel/proximal colon, which may warrant further studies to evaluate clinical applicability.

Review article: issues in oral administration of locally acting glucocorticosteroids for treatment of inflammatory bowel disease

Inflammatory bowel diseases are treated in some cases by local administration of anti-inflammatory drugs. Local delivery of drugs in the colon following oral administration may lead to improved efficacy/side-effect profiles and may improve patient compliance. This review covers a number of issues important in the design of oral delivery systems of glucocorticosteroids for local therapy of colonic inflammation. The choice of specific glucocorticosteroids is based on the drug's physicochemical and pharmacological properties. The conditions under which an orally administered glucocorticosteroid (or other drug) must be delivered to treat ulcerative colitis are also discussed. These conditions include variations in local pH, transit throughout the gastrointestinal tract, the potential role of gut microflora, and drug dissolution in both the healthy and diseased large intestine. The effective delivery of topically-active glucocorticosteroids in ulcerative colitis and Crohn's colitis patients is complex, but if successful could improve their usefulness.

A practical guide to the management of distal ulcerative colitis

This article reviews the role of corticosteroids, sulfasalazine and mesalazine (5-aminosalicylic acid, mesalamine), immunosuppressive agents and alternative novel drugs for the treatment of distal ulcerative colitis. Short cycles of traditional, rectally administered corticosteroids (methylprednisolone, betamethasone, hydrocortisone) are effective for the treatment of mild to moderately active distal ulcerative colitis. In this context, their systemic administration is limited to patients who are refractory to either oral 5-amino-salicylates, topical mesalazine or topical corticosteroids. Of no value in maintaining remission, the long term use of either or topical corticosteroids may be hazardous. A new class of topically acting corticosteroids [budesonide, fluticasone, beclomethasone dipropionate, prednisolone-21-methasulphobenzoate, tixocortol (tixocortol pivalate)] represents a valid alternative for the treatment of active ulcerative colitis, and may be useful in the treatment of refractory distal ulcerative colitis. Although there is controversy concerning dosage or duration of therapy, oral and topical mesalazine is effective in the treatment of mild to moderately active distal ulcerative colitis. Sulfasalazine and mesalazine remain the first-choice drugs for the maintenance therapy of distal ulcerative colitis. Evidence exists showing a trend to a higher remission rate with higher doses of oral mesalazine. Topical mesalazine (suppositories or enemas) also is effective in maintenance treatment. For patients with chronically active or corticosteroid-dependent disease, azathioprine and mercaptopurine are effective in reducing either the need for corticosteroids or clinical relapses. Moreover, they are effective for long term maintenance remission. Cyclosporin may be useful in inducing remission in patients with acutely severe disease who do not achieve remission with an intensive intravenous regimen. Existing data suggest that azathioprine and mercaptopurine may be effective in prolonging remission in these patients. The role of alternative drugs for the treatment of distal ulcerative colitis and its different forms is reviewed. In particular data are reported concerning the effectiveness of 5-lipoxygenase inhibitors, topical use of short chain fatty acids, nicotine, local anaesthetics, bismuth subsalicylate enema, sucralfate, clonidine, free radical scavengers, heparin and hydroxychloroquine.

Colonic luminal hydrogen sulfide is not elevated in ulcerative colitis

It has been proposed that the reduction in n-butyrate oxidation by colonic epithelial cells observed in ulcerative colitis may be related to exposure to reduced forms of sulfur derived from dissimilatory sulfate reduction by luminal microflora. This study aims to compare stool sulfide concentrations in control and colitic subjects. Control subjects had significant colorectal disease excluded by virtue of their selection. Patients with ulcerative colitis were stratified by disease extent and activity, and by salicylate drug use. Stool sulfide was measured using a direct spectrophotometric method on NaOH (free sulfide) and zinc acetate (total sulfide) stool slurries. Fifteen control and 19 colitic subjects were studied. There was no significant difference in stool sulfide between control and colitic patients (free sulfide, control = 0.52 (0.17), colitic = 0.45 (0.10), t = 0.36, P = 0.71, total sulfide, control = 1.33 (0.21), colitic = 0.96 (0.15), t = 1.44, P = 0.16). Disease extent or activity did not significantly influence stool sulfide. These results do not support a primary etiologic role for luminal sulfide in ulcerative colitis.

Innovations in topical therapy

Topical therapy can be considered the standard treatment for distal ulcerative colitis. The group of drugs of first choice are the aminosalicylates which are effective in inducing remission in acute disease as well as in preventing relapse. Corticosteroids appear to be slightly less effective and have no proven benefit in maintenance therapy. With new topical steroids, such as budesonide, systemic effects can be minimized. The major role of corticosteroids is to complement aminosalicylates, when necessary. The new topical compounds appear to be especially valuable when there is a long-term requirement for corticosteroids. With the vast majority of patients obtaining remission with standard treatment, it is difficult to make the case for alternative substances. Short-chain fatty acids, local anaesthetics and bismuth compounds seem to be the most promising innovations in topical therapy although their equivalence or even superiority to mesalazine has not been established.

A randomised trial comparing mesalazine and prednisolone foam enemas in patients with acute distal ulcerative colitis

Distal ulcerative colitis can be treated with oral or rectal mesalazine, or both. A foam enema preparation has been developed and its efficacy investigated. The aim of this study was to evaluate the efficacy and safety of mesalazine foam enemas compared with prednisolone foam enemas in the treatment of patients with acute distal ulcerative colitis. Patients aged over 18 years presenting with a relapse of distal ulcerative colitis were randomly allocated treatment with mesalazine foam enema (n = 149 evaluable patients) and prednisolone foam enema (n = 146 evaluable patients) for four weeks. A randomised multicentre investigator blind parallel group trial was conducted. It was found that after four weeks of treatment, clinical remission was achieved by 52% of mesalazine treated patients and 31% of patients treated with prednisolone (p < 0.001). There was a trend in favour of more patients in the mesalazine group achieving sigmoidoscopic remission (40% v 31%, p = 0.10). Histological remission was achieved by 27% and 21% of patients receiving mesalazine and prednisolone respectively. Symptoms improved in both treatment groups. Significantly more mesalazine patients had no blood in their stools after four weeks of treatment (67% v 40%, p < 0.001). Prednisolone treated patients had significantly fewer days with liquid stools than mesalazine patients, with a median of 0 and 1 days respectively by week 4 (p = 0.001). In this study mesalazine foam enema was superior to prednisolone foam enema with regards to clinical remission, this was supported by favourable trends in sigmoidoscopic and histological remission rates. Both treatments were well tolerated.

Review article: topical corticosteroids in inflammatory bowel disease

It would be ideal to treat inflammatory bowel disease with topical corticosteroids that are either not absorbed through the mucosa, or have a substantial first-pass hepatic metabolism. The topical use of hydrocortisone, prednisolone-21-phosphate or betamethasone is often associated with systemic side-effects. Newer corticosteroid preparations (prednisolone metasulphobenzoate, tixocortol pivalate, fluticasone propionate, beclomethasone dipropionate and budesonide) are usually associated with minimal systemic corticosteroid activity. This article reviews the clinical activity and safety of these newer preparations.

Current management of inflammatory bowel disease

The aetiology of ulcerative colitis and Crohn's disease remains unknown. While this remains so, treatment must be directed towards pathogenetic mechanisms. Corticosteroids, sulphasalazine and the new salicylates, the immunosuppressants azathioprine, 6-MP and, more recently, cyclosporin and metronidazole have become the accepted and standard forms of treatment. The importance of maintaining nutritional status is often overlooked but must be considered in every patient. Recognition of the occurrence of disease in all age groups, and in particular in children and adolescents, is also important, as is an appreciation of the special problems involved. The possibility of surgery at some stage of the disease should be raised with the patient. As the pathogenetic mechanisms of inflammatory bowel disease are further elucidated, new forms of treatment will be developed. This is already happening, with studies looking at such agents as immunoglobulin G, eicosapentaenoic acid and a new specific inhibitor of 5-lipoxygenase. These offer hope of more potent drugs with low side-effect profiles that may complement or replace the currently available agents used in the management of inflammatory bowel disease.

New therapeutic agents in the treatment of inflammatory bowel disease

Despite intense investigation, the etiology of inflammatory bowel disease (IBD) remains unknown. Recent studies with new therapeutic agents provide insight into the pathogenesis of IBD through analysis of the clinical response to pharmacologic agents whose mechanism of action is understood. Until new agents are established, IBD will be treated with conventional drugs directed toward modifying the inflammatory responses responsible for gastrointestinal mucosal damage. Sulfasalazine, mesalamine (5-aminosalicylic acid), and corticosteroids will continue to be the mainstay of therapy for the foreseeable future. Antibiotics such as metronidazole and immunosuppressants such as 6-mercaptopurine and methotrexate are useful in Crohn's disease and ulcerative colitis in selected cases. Many new exciting agents are being investigated and show encouraging results in the treatment of IBD. This article reviews the agents used in IBD with an emphasis on new therapeutic agents.

Drug management of ulcerative colitis

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Effect of butyrate enemas on the colonic mucosa in distal ulcerative colitis

Short-chain fatty acid irrigation has been shown to ameliorate inflammation in diversion colitis. In this study the effect of butyrate enemas was tested in 10 patients with distal ulcerative colitis who had been unresponsive to or intolerant of standard therapy for 8 weeks. They were treated for 2 weeks with sodium butyrate (100 mmol/L) and 2 weeks with placebo in random order (single-blind trial). Before and after treatment, clinical symptoms were noted and the degree of inflammation was graded endoscopically and histologically. Rectal proliferation was assessed by autoradiography. After butyrate irrigation, stool frequency (n/day) decreased from 4.7 +/- 0.5 to 2.1 +/- 0.4 (P less than 0.01) and discharge of blood ceased in 9 of 10 patients. The endoscopic score fell from 6.5 +/- 0.4 to 3.8 +/- 0.8 (P less than 0.01). The histological degree of inflammation decreased from 2.4 +/- 0.3 to 1.5 +/- 0.3 (P less than 0.02). Overall crypt proliferation was unchanged, but the upper crypt-labeling index fell from 0.086 +/- 0.019 to 0.032 +/- 0.003 (P less than 0.03). On placebo, all of these parameters were unchanged. These data support the view that butyrate deficiency may play a role in the pathogenesis of distal ulcerative colitis and that butyrate irrigation ameliorates this condition.

Oral fluticasone propionate in active distal ulcerative colitis

Fluticasone propionate is a new corticosteroid with low systemic bioavailability. This study reports the outcome of a double blind clinical trial comparing oral fluticasone propionate (5 mg four times daily) with placebo for the treatment of active distal ulcerative colitis. Sixty patients were treated for four weeks, with assessments at two and four weeks. One patient was withdrawn when she was found to have amoebiasis. Thus, results are presented for 29 patients who received placebo and 30 who received fluticasone propionate. The two groups were well matched for age, sex, length of history, and extent of disease. After four weeks of therapy the clinical, sigmoidoscopic, and histological responses were similar in the two groups. It is concluded that fluticasone propionate (5 mg four times daily) is not effective treatment for active distal ulcerative colitis.

An Eudragit-coated prednisolone preparation for ulcerative colitis: pharmacokinetics and preliminary therapeutic use

Prednisolone metasulphabenzoate, a steroid with poor colonic absorption, was coated with the pH-dependent acrylic resin Eudragit S, as a means of delivering an orally administered preparation to the proximal colon. The therapeutic potential of delivering this steroid with potentially less systemic side-effects to the proximal colon was assessed in extensive ulcerative colitis. Plasma and urine prednisolone profiles in 6 healthy volunteers confirmed minimal absorption from Eudragit S-coated prednisolone metasulphabenzoate compared to prednisolone acetate: peak plasma prednisolone concentrations 29 +/- 21 ng/ml vs. 570 +/- 185 ng/ml (P less than 0.01), area under curve measurements 204 +/- 214 vs. 2724 +/- 1236 ng.h/ml (P less than 0.01). Prednisolone metasulphabenzoate coated with Eudragit S (30-60 mg daily) was then administered for 12 weeks to 12 patients with colonoscopically proven extensive ulcerative colitis in relapse. Symptoms, sigmoidoscopic appearances and rectal histological abnormalities all improved during therapy. Complete clinical remission occurred in 7 patients, a partial response in 2 patients and no response in 3 patients. Cortisol responses to tetracosactrin demonstrated no significant adrenal suppression following treatment. Eudragit S-coated prednisolone metasulphabenzoate may be a useful treatment for extensive ulcerative colitis, without risk of systemic steroid side-effects.

Budesonide enema in distal ulcerative colitis. A randomized dose-response trial with prednisolone enema as positive control. The Danish Budesonide Study Group

The effect of budesonide, 1, 2, and 4 mg/100 ml in daily enemas, on active distal ulcerative colitis was compared with that of prednisolone disodium phosphate enemas, 25 mg/100 ml, in a multicentre, randomized, group-comparative trial. A total of 146 patients with active disease were treated for 2 weeks. Data from 139 were valid for statistical analyses. Bowel habits, proctoscopy findings, and histologic pictures were evaluated, and plasma cortisol was determined for measurement of influence on the hypothalamic-pituitary-adrenal axis. Clinical symptoms and proctoscopy findings improved within all treatment groups. The improvement of these effect variables tended to be less after treatment with the lowest dose of budesonide, 1 mg/100 ml, than after the other treatments. Plasma cortisol did not change in any of the budesonide groups, whereas a mean reduction of 30% (P = 0.07) was observed after prednisolone. It can be concluded that budesonide enemas of 2 mg/100 ml constitute an attractive alternative to prednisolone enemas for topical treatment of distal ulcerative colitis.

Risk-benefit assessment of drugs used in the treatment of inflammatory bowel disease

Although the aetiology of inflammatory bowel disease remains elusive, many agents are available for the control of symptoms and inflammation. Knowledge of drug pharmacology, indications and side effects is essential to ensure the best possible clinical care while minimising toxicity and inappropriate use. Sulfasalazine consists of sulfapyridine linked to mesalazine (5-aminosalicylic acid) via an azobond. Its use is indicated in the treatment of mild to moderately active ulcerative colitis and in the prevention of relapse in patients with quiescent disease. Patients with mild to moderate colonic or ileocolonic Crohn's disease also benefit from this drug, as do a proportion of patients with isolated small bowel disease. Sulfasalazine has not been uniformly effective in preventing relapse in Crohn's disease, although many clinicians continue its use in patients who respond initially. A high incidence of side effects which limit therapy include intolerance, hypersensitivity reactions and impairment of male infertility. The newer aminosalicylates offer targeted delivery of mesalazine to the bowel, with fewer side effects. Topical mesalazine has proved extremely effective in patients with distal ulcerative colitis; oral forms are effective in the treatment of mild to moderately active ulcerative colitis and in relapse. Both types appear to be effective in the treatment of Crohn's disease, and possibly in preventing relapse. There is no current clinical advantage of one mesalazine preparation over another, nor is there an indication for their use in sulfasalazine-treated patients who have satisfactory response without adverse effects. Corticosteroids are indicated for more severe disease activity where the aminosalicylates have limited efficacy-specifically to induce remission in patients with severe or refractory ulcerative colitis or Crohn's disease. They should not be used to maintain disease remission or in the prevention of postoperative recurrence. Topical corticosteroids allow their local use in distal colitis with minimal systemic side effects. Long term use is limited by side effects, many of which are dose related, although alternate-day therapy may lessen the incidence. Immunosuppressive agents are beneficial for the treatment of refractory inflammatory bowel disease unresponsive to other medications, and may also facilitate the withdrawal of steroids in refractory patients. Mercaptopurine has an added benefit in the treatment of Crohn's disease fistulae; the role of cyclosporin in bowel disease has not been established and its use cannot currently be recommended. The potential toxicity of immunosuppressive agents warrants careful consideration of their use by both physician and patient. Metronidazole is indicated for the treatment of mild to moderate Crohn's disease, including perineal disease. Common side effects include peripheral neuropathy and nausea.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical pharmacokinetics of prednisone and prednisolone

The growth of knowledge in the field of the pharmacokinetics of prednisolone/prednisone has been slow for several reasons. First, convenient and specific methods for measuring these steroids only became available with the development of high performance liquid chromatographic methods. Secondly, prednisolone is nonlinearly bound to transcortin and albumin: since the unbound concentrations of prednisolone are biologically relevant, it was necessary to determine the free fraction in each plasma sample. Thirdly, due to the short half-life of prednisolone no steady-state is achieved, and therefore area under the concentration-time curve needed to be determined in all studies. Fourthly, prednisolone and prednisone are interconvertible and prednisolone is given intravenously as an ester prodrug, features which created controversies about the correct interpretation of pharmacokinetic results. Finally, the total body clearances of total and (to a lesser degree) of unbound prednisolone increase with increasing concentrations of prednisolone. Therefore, in order to compare pharmacokinetic results between different subjects, standardised doses had to be administered. The investigations performed so far have revealed that: (1) the dose-dependent pharmacokinetics partly explain the clinical observation that an alternate-day regimen with prednisone yields fewer biological effects; (2) the interconversion of prednisone into prednisolone is not a limiting factor, even in patients with severely impaired liver function; (3) hypoproteinaemia per se does not cause increased unbound concentrations of prednisolone in vivo; (4) patients with liver failure, renal failure or a renal transplant, subjects older than 65 years, women on estrogen-containing oral contraceptive steroids or subjects taking ketoconazole have increased unbound concentrations of prednisolone-whereas hyperthyroid patients, some patients with Crohn's disease, subjects taking microsomal liver enzyme-inducing agents or patients on intravenous prednisolone phthalate (instead of prednisolone phosphate) or on some brands of enteric coated prednisolone tablets have decreased concentrations of prednisolone. The biological relevance of the altered pharmacokinetics is supported in part by altered clinical effects and altered effects on cellular immunofunctions.

Inflammatory bowel disease revisited: newer drugs

The development of new drug therapy is an evolutionary process progressing from clinical success with current treatments through an understanding of interactions in the immune and inflammatory events that culminate in the tissue injury of IBD. The basic immunoinflammatory response is reviewed, with identification of the recognized and potential sites of activity of current therapies. Potential sites and implications for future interventions by newer therapies are discussed as we anticipate the discovery of the etiology and eventual cure for ulcerative colitis and Crohn's disease.

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.

A comparison of sucralfate and prednisolone enemas in the treatment of active distal ulcerative colitis

Sucralfate is well established in the treatment of upper gastrointestinal inflammation and ulceration, and preliminary evidence suggests it may be of benefit in active colitis. We have therefore undertaken a clinical trial to compare enemas of sucralfate (4 g) and prednisolone metasulphobenzoate (20 mg) in the treatment of active distal ulcerative colitis. Forty-four patients were entered into a 4-week study. Two patients were withdrawn because of non-compliance, and five were unable to complete the study: two developed constipation (both allocated to sucralfate) and three were unable to retain the enemas (two prednisolone and one sucralfate). Intention-to-treat analysis showed significant within-treatment improvement in rectal bleeding, sigmoidoscopic grade, and histologic grade in the prednisolone-treated group, and in stool frequency, rectal bleeding, and sigmoidoscopic grade in the sucralfate-treated group. Between-treatment comparisons, however, showed greater resolution of rectal bleeding and more marked improvements in histologic grade in patients treated with prednisolone metasulphobenzoate enemas. Further studies using higher doses of sucralfate would be useful.

Inflammatory bowel disease

An increasing number of options are available for the treatment of inflammatory bowel disease; the selection depends on the extent and severity of the disease. Experience with sulfasalazine and corticosteroids has led to a proliferation of 5-aminosalicylic acid (5-ASA) compounds and experimentation with alternative corticosteroid preparations. Given rectally 5-ASA is particularly effective in the treatment of distal ulcerative colitis, and experience is accumulating with several oral formulations. Metronidazole is useful in some cases, and immunosuppressive agents have a role in some patients with chronic refractory disease. A variety of measures, such as nutritional therapy, surgery and psychosocial support, are important elements of therapy. Further therapeutic innovations are expected as the etiology and pathogenesis are clarified.

5-Aminosalicylic acid enemas in treatment of distal ulcerative colitis and proctitis in Canada

The efficacy and safety of 4 g 5-aminosalicylic acid (5-ASA) enemas were assessed in 59 patients with ulcerative colitis involving up to 50 cm of their distal colon. Twenty-nine patients received 5-ASA and 30 received a placebo. There were 12 dropouts (five in the active and seven in the placebo group) during the study because of insufficient efficacy. After six weeks of therapy, 63% of the patients receiving the 5-ASA were considered to be "much improved" by the study physician compared to 20% patients on placebo (P less than 0.0001). A disease activity index (DAI), based upon patient symptoms and sigmoidoscopic appearance, was used to assess efficacy. Mean DAI declined 75% for patients on 5-ASA enemas and 32% for patients on placebo (P less than 0.05). The 5-ASA enemas are well tolerated and are of benefit in the treatment of ulcerative colitis confined to the distal colon.

Medical treatment of inflammatory bowel disease: new therapies, new drugs

Ulcerative colitis, ulcerative proctitis and Crohn's disease are chronic inflammatory conditions that affect the gastrointestinal tract. Conventional treatment has stressed the role of anti-inflammatory agents to suppress the inflammatory response. New compounds that can deliver 5-aminosalicylic acid to the colon have recently been released in Canada. Metronidazole and azathioprine may also be of benefit in Crohn's disease. Therapy with cyclosporine and clonidine should be based on the results of further clinical trials. The use of nutritional support as primary therapy in Crohn's disease appears promising. At present, both pharmacologic and nutritional therapies should be considered in the treatment of inflammatory bowel disease.

Treatment of distal ulcerative colitis with beclomethasone enemas: high therapeutic efficacy without endocrine side effects. A prospective, randomized, double-blind trial

Sixteen patients with 18 attacks of distal ulcerative colitis were treated randomly with either 0.5 mg topically administered beclomethasone dipropionate (BDP) or 5 mg betamethasone phosphate (BMT). The effect of the steroid enemas on adrenocortical function was examined by ACTH tests, which were performed before and 20 days after treatment. At completion of the trial, a marked suppression of the adrenocortical function was found in seven of eight patients treated for nine attacks with BMT but not in any patients in the BDP group (P less than 0.01). The mean posttreatment basal and stimulated plasma cortisol levels in the BMT group were significantly lower as compared with the BDP group. The overall therapeutic response assessed by score systems was comparable in the two treatment groups. It is concluded that, in the topical treatment of ulcerative colitis, BDP is preferable to BMT because it exerts an equal anti-inflammatory action without affecting adrenocortical function.