6-mercaptopurine therapy in selected cases of corticosteroid-dependent Crohn's disease

Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

BACKGROUND

The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease have been conflicting and controversial. An updated meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's disease.

OBJECTIVES

The primary objective was to determine the efficacy and safety of azathioprine and 6-mercaptopurine for induction of remission in active Crohn's disease.

SEARCH METHODS

We searched MEDLINE, EMBASE and the Cochrane Library from inception to 30 October 2015. Review articles and conference proceedings were also searched to identify additional studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of oral azathioprine or 6-mercaptopurine compared to placebo or active therapy involving adult patients with active Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent observers based on the intention-to-treat principle. Outcomes of interest included: clinical remission, clinical improvement, fistula improvement or healing, steroid sparing, adverse events, withdrawals due to adverse events and serious adverse events. We calculated the pooled relative risk (RR) and 95% confidence intervals (95% CI) for each outcome. The methodological quality of included studies was evaluated using the Cochrane risk of bias tool. The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

Thirteen RCTs (n = 1211 patients) of azathioprine and 6-mercaptopurine therapy in adult patients were identified: nine included placebo comparators and six included active comparators. The majority of included studies were rated as low risk of bias. There was no statistically significant difference in clinical remission rates between azathioprine or 6-mercaptopurine and placebo. Forty-eight per cent (95/197) of patients receiving antimetabolites achieved remission compared to 37% (68/183) of placebo patients (5 studies, 380 patients; RR 1.23, 95% CI 0.97 to 1.55). There was no statistically significant difference in clinical improvement rates between azathioprine or 6-mercaptopurine and placebo. Forty-eight per cent (107/225) of patients receiving antimetabolites achieved clinical improvement or remission compared to 36% (75/209) of placebo patients (8 studies, 434 patients; RR 1.26, 95% CI 0.98 to 1.62). There was a statistically significant difference in steroid sparing (defined as prednisone dose < 10 mg/day while maintaining remission) between azathioprine and placebo. Sixty-four per cent (47/163) of azathioprine patients were able to reduce their prednisone dose to < 10 mg/day compared to 46% (32/70) of placebo patients (RR 1.34, 95% CI 1.02 to 1.77). GRADE analyses rated the overall quality of the evidence for the outcomes clinical remission, clinical improvement and steroid sparing as moderate due to sparse data. There was no statistically significant difference in withdrawals due to adverse events or serious adverse events between antimetabolites and placebo. Ten percent of patients in the antimetabolite group withdrew due to adverse events compared to 5% of placebo patients (8 studies, 510 patients; RR 1.70, 95% CI 0.94 to 3.08). Serious adverse events were reported in 14% of patients receiving azathioprine compared to 4% of placebo patients (2 studies, 216 patients; RR 2.57, 95% CI 0.92 to 7.13). Common adverse events reported in the placebo controlled studies included: allergic reactions. leukopenia, pancreatitis and nausea. Azathioprine was significantly inferior to infliximab for induction of steroid-free clinical remission. Thirty per cent (51/170) of azathioprine patients achieved steroid-free remission compared to 44% (75/169) of infliximab patients (1 study, 339 patients; RR 0.68, 95% CI 0.51 to 0.90). The combination of azathioprine and infliximab was significantly superior to infliximab alone for induction of steroid-free clinical remission. Sixty per cent (116/194) of patients in the combined azathioprine and infliximab group achieved steroid-free remission compared to 48% (91/189) of infliximab patients (2 studies, 383 patients; RR 1.23, 95% CI 1.02 to 1.47). Azathioprine or 6-mercaptopurine therapy was found to be no better at inducing steroid free clinical remission compared to methotrexate (RR 1.13, 95% CI 0.85 to 1.49) and 5-aminosalicylate or sulfasalazine (RR 1.24, 95% CI 0.80 to 1.91). There were no statistically significant differences in withdrawals due to adverse events between azathioprine or 6-mercaptopurine and methotrexate (RR 0.78, 95% CI 0.23 to 2.71); between azathioprine or 6-mercaptopurine and 5-aminosalicylate or sulfasalazine (RR 0.98, 95% CI 0.38 to 2.54); between azathioprine and infliximab (RR 1.47, 95% CI 0.96 to 2.23); or between the combination of azathioprine and infliximab and infliximab (RR 1.16, 95% CI 0.75 to 1.80). Common adverse events in the active comparator trials included nausea, abdominal pain, pyrexia and headache.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine offer no advantage over placebo for induction of remission or clinical improvement in active Crohn's disease. Antimetaboilte therapy may allow patients to reduce steroid consumption. Adverse events were more common in patients receiving antimetabolites although differences with placebo were not statistically significant. Azathioprine therapy is inferior to infliximab for induction of steroid-free remission. However, the combination of azathioprine and infliximab was superior to infliximab alone for induction of steroid-free remission.

Outpatient management of inflammatory bowel disease

Inflammatory bowel disease is a conglomeration of disorders of unclear etiology and pathogenesis. Confirming the diagnosis of active disease may be difficult but is critical to judicious therapy. Sulfasalazine (Azulfidine) and its newer derivatives mesalamine (Asacol, Rowasa) and olsalazine sodium (Dipentum) are used for treatment of mild disease and maintenance. Corticosteroid therapy controls moderate disease in most patients, but withdrawal may be difficult. Immunosuppression or surgery may be necessary in severe or refractory cases. The risk of cancer as a complication of inflammatory bowel disease is often exaggerated but cannot be ignored.

Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

BACKGROUND

The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease have been conflicting and controversial. An updated meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's disease.

OBJECTIVES

The primary objective was to determine the efficacy and safety of azathioprine and 6-mercaptopurine for induction of remission in active Crohn's disease.

SEARCH METHODS

A literature search for relevant studies (inception to June 13, 2012) was performed using MEDLINE, EMBASE and the Cochrane Library. Review articles and conference proceedings were also searched to identify additional studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of oral azathioprine or 6-mercaptopurine compared to placebo or active therapy involving adult patients with active Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent observers based on the intention-to-treat principle. Outcomes of interest included: clinical remission, clinical improvement, fistula improvement or healing, steroid sparing, adverse events, withdrawals due to adverse events and serious adverse events. We calculated the pooled relative risk (RR) and 95% confidence intervals (95% CI) for each outcome. The methodological quality of included studies was evaluated using the Cochrane risk of bias tool. The overall quality of the evidence supporting each outcome was assessed using the GRADE criteria.

MAIN RESULTS

Thirteen RCTs (n = 1211 patients) of azathioprine and 6-mercaptopurine therapy in adult patients were identified: nine included placebo comparators and six included active comparators. The majority of included studies were rated as low risk of bias. There was no statistically significant difference in clinical remission rates between azathioprine or 6-mercaptopurine and placebo. Forty-eight per cent (95/197) of patients receiving antimetabolites achieved remission compared to 37% (68/183) of placebo patients (5 studies, 380 patients; RR 1.23, 95% CI 0.97 to 1.55). There was no statistically significant difference in clinical improvement rates between azathioprine or 6-mercaptopurine and placebo. Forty-eight per cent (107/225) of patients receiving antimetabolites achieved clinical improvement or remission compared to 36% (75/209) of placebo patients (8 studies, 434 patients; RR 1.26, 95% CI 0.98 to 1.62). There was a statistically significant difference in steroid sparing (defined as prednisone dose < 10 mg/day while maintaining remission) between azathioprine and placebo. Sixty-four per cent (47/163) of azathioprine patients were able to reduce their prednisone dose to < 10 mg/day compared to 46% (32/70) of placebo patients (RR 1.34, 95% CI 1.02 to 1.77). GRADE analyses rated the overall quality of the evidence for the outcomes clinical remission, clinical improvement and steroid sparing as moderate due to sparse data. There was no statistically significant difference in withdrawals due to adverse events or serious adverse events between antimetabolites and placebo. Ten percent of patients in the antimetabolite group withdrew due to adverse events compared to 5% of placebo patients (8 studies, 510 patients; RR 1.70, 95% CI 0.94 to 3.08). Serious adverse events were reported in 14% of patients receiving azathioprine compared to 4% of placebo patients (2 studies, 216 patients; RR 2.57, 95% CI 0.92 to 7.13). Common adverse events reported in the placebo controlled studies included: allergic reactions. leukopenia, pancreatitis and nausea. Azathioprine was significantly inferior to infliximab for induction of steroid-free clinical remission. Thirty per cent (51/170) of azathioprine patients achieved steroid-free remission compared to 44% (75/169) of infliximab patients (1 study, 339 patients; RR 0.68, 95% CI 0.51 to 0.90). The combination of azathioprine and infliximab was significantly superior to infliximab alone for induction of steroid-free clinical remission. Sixty per cent (116/194) of patients in the combined azathioprine and infliximab group achieved steroid-free remission compared to 48% (91/189) of infliximab patients (2 studies, 383 patients; RR 1.23, 95% CI 1.02 to 1.47). Azathioprine or 6-mercaptopurine therapy was found to be no better at inducing steroid free clinical remission compared to methotrexate (RR 1.13, 95% CI 0.85 to 1.49) and 5-aminosalicylate or sulfasalazine (RR 1.24, 95% CI 0.80 to 1.91). There were no statistically significant differences in withdrawals due to adverse events between azathioprine or 6-mercaptopurine and methotrexate (RR 0.78, 95% CI 0.23 to 2.71); between azathioprine or 6-mercaptopurine and 5-aminosalicylate or sulfasalazine (RR 0.98, 95% CI 0.38 to 2.54); between azathioprine and infliximab (RR 1.47, 95% CI 0.96 to 2.23); or between the combination of azathioprine and infliximab and infliximab (RR 1.16, 95% CI 0.75 to 1.80). Common adverse events in the active comparator trials included nausea, abdominal pain, pyrexia and headache.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine offer no advantage over placebo for induction of remission or clinical improvement in active Crohn's disease. Antimetaboilte therapy may allow patients to reduce steroid consumption. Adverse events were more common in patients receiving antimetabolites although differences with placebo were not statistically significant. Azathioprine therapy is inferior to infliximab for induction of steroid-free remission. However, the combination of azathioprine and infliximab was superior to infliximab alone for induction of steroid-free remission.

Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

BACKGROUND

The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease were conflicting and controversial. A meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's disease.

OBJECTIVES

To determine the effectiveness of azathioprine and 6-mercaptopurine in inducing remission of active Crohn's disease.

SEARCH STRATEGY

Studies were selected using the MEDLINE database (1966 to July 2009), abstracts from major gastrointestinal meetings and references from published articles and review. The Cochrane Trials Register and the Inflammatory Bowel Disease Review Group Trials Register were also searched. This search strategy was updated using the MEDLINE, EMBASE and the International Pharmaceutical Abstracts databases as well as the Cochrane Register of Controlled Trials and the Cochrane IBD/FBD group Specialized Trials Register.

SELECTION CRITERIA

Randomized, double-blind, placebo-controlled trials of oral azathioprine or 6-mercaptopurine involving adult patients (> 18 years) with active Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers based on the intention to treat principle. Each study was given a quality score based on predetermined criteria. Extracted data were converted to 2X2 tables (response versus no response and antimetabolite versus placebo) and then synthesized into a summary test statistic using the pooled odds ratio and 95% confidence intervals as described by Cochran and Mantel and Haenszel.

MAIN RESULTS

Eight randomized placebo controlled trials of azathioprine and 6-mercaptopurine therapy in adult patients were identified: five dealt with active disease and three had multiple therapeutic arms. The odds ratio (OR) of a response to azathioprine or 6-mercaptopurine therapy compared with placebo in active Crohn's disease was 2.43 (95% CI 1.62 to 3.64). This corresponded to a number needed to treat (NNT) of about 5 to observe an effect of therapy in one patient. When the two trials using 6-mercaptopurine in active disease were excluded from the analysis, the OR was 2.06 (95% CI 1.25 to 3.39). Treatment of > 17 weeks resulted in an OR of 2.61 (95% CI 1.69 to 4.03). A steroid sparing effect was seen with an OR of 3.69 (95% CI 2.12 - 6.42), corresponding to a NNTof about 3 to observe steroid sparing in one patient. Adverse events requiring withdrawal from a trial, principally allergy, leukopenia, pancreatitis, and nausea were increased with active therapy with an odds ratio of 3.44 (95% CI 1.52 to 7.77). The NNT to observe one adverse event in one patient treated with azathioprine or 6-mercaptopurine was 14.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine are effective therapy for inducing remission in active Crohn's disease. Adverse events were more common among patients on active therapy.

Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

BACKGROUND

The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease were conflicting and controversial. A meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's disease.

OBJECTIVES

To determine the effectiveness of azathioprine and 6-mercaptopurine in inducing remission of active Crohn's disease.

SEARCH STRATEGY

Studies were selected using the MEDLINE database (1966 to July 2009), abstracts from major gastrointestinal meetings and references from published articles and review. The Cochrane Trials Register and the Inflammatory Bowel Disease Review Group Trials Register were also searched. This search strategy was updated using the MEDLINE, EMBASE and the International Pharmaceutical Abstracts databases as well as the Cochrane Register of Controlled Trials and the Cochrane IBD/FBD group Specialized Trials Register.

SELECTION CRITERIA

Randomized, double-blind, placebo-controlled trials of oral azathioprine or 6-mercaptopurine involving adult patients (> 18 years) with active Crohn's disease were selected for inclusion.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers based on the intention to treat principle. Each study was given a quality score based on predetermined criteria. Extracted data were converted to 2X2 tables (response versus no response and antimetabolite versus placebo) and then synthesized into a summary test statistic using the pooled odds ratio and 95% confidence intervals as described by Cochran and Mantel and Haenszel.

MAIN RESULTS

Eight randomized placebo controlled trials of azathioprine and 6-mercaptopurine therapy in adult patients were identified: five dealt with active disease and three had multiple therapeutic arms. The odds ratio (OR) of a response to azathioprine or 6-mercaptopurine therapy compared with placebo in active Crohn's disease was 2.43 (95% CI 1.62 to 3.64). This corresponded to a number needed to treat (NNT) of about 5 to observe an effect of therapy in one patient. When the two trials using 6-mercaptopurine in active disease were excluded from the analysis, the OR was 2.06 (95% CI 1.25 to 3.39). Treatment > 17 weeks increased the OR to 2.61 (95% CI 1.69 to 4.03). A steroid sparing effect was seen with an OR of 3.69 (95% CI 2.12 - 6.42), corresponding to a NNTof about 3 to observe steroid sparing in one patient. Adverse events requiring withdrawal from a trial, principally allergy, leukopenia, pancreatitis, and nausea were increased with active therapy with an odds ratio of 3.44 (95% CI 1.52 to 7.77). The NNT to observe one adverse event in one patient treated with azathioprine or 6-mercaptopurine was 14.

AUTHORS' CONCLUSIONS

Azathioprine and 6-mercaptopurine are effective therapy for inducing remission in active Crohn's disease. The OR of response increases after > 17 weeks of therapy, suggesting that there is a minimum length of time for a trial of azathioprine or 6-mercaptopurine therapy. Adverse events were more common among patients on active therapy.

Immunomodulatory therapy for pediatric inflammatory bowel disease: changing patterns of use, 1990-2000

OBJECTIVE

To identify changes over the past decade in physicians' attitudes regarding the use of immunomodulatory agents for the treatment of children with inflammatory bowel disease (IBD), we surveyed the membership of the North American Society for Pediatric Gastroenterology and Nutrition and compared the responses to those from an identical survey performed in 1990.

METHODS

Surveys were mailed to 718 physicians in January, 2000. All surveys returned by mid-February were analyzed, and results compared to those obtained in the 1990 survey.

RESULTS

Thirty-nine percent (278/718) of surveys were returned, compared to 27% (105/385) in 1990. Overall, 93% of the current survey's respondents agreed with the statement "immunomodulatory agents are effective in the treatment of children and adolescents with IBD." Compared to 1990, significant increases (p < 0.0001) were noted in the percentage of respondents who prescribe immunomodulatory agents to children with all forms of IBD. Indications for immunomodulation that showed significant increases (p < 0.001) since 1990 included treatment of perianal and non-perianal fistulae; growth failure; use as initial, primary therapy; and use as prophylaxis against postoperative recurrence. 6-Mercaptopurine and azathioprine continue to be the agents prescribed by the greatest percentage of respondents. More physicians are willing to use immunomodulatory agents in children younger than 5 yr, and duration of use is longer than in 1990. Currently, physicians seem to favor the use of immunomodulatory agents over colectomy for children with either intractable ulcerative or Crohn's colitis. Most respondents remain concerned about potential bone marrow and immune suppression, but concerns regarding malignancy, teratogenicity, and infertility have lessened.

CONCLUSION

These survey findings document that pediatric gastroenterologists have widely accepted the use of immunomodulators in the treatment of children and adolescents with IBD.

A multicenter trial of 6-mercaptopurine and prednisone in children with newly diagnosed Crohn's disease

BACKGROUND & AIMS

Clinical experience suggests that 6-mercaptopurine (6-MP) is effective therapy for children with active steroid-dependent Crohn's disease (CD). We report the results of a prospective, placebo-controlled, multicenter trial evaluating the combination of 6-MP and prednisone as therapy for children with newly diagnosed moderate-to-severe CD.

METHODS

Fifty-five children (age, 13+/-2 years) were randomized to treatment with 6-MP (1.5 mg x kg(-1) x day(-1)) or placebo within 8 weeks of initial diagnosis. Both groups also received prednisone (40 mg/day). Prednisone dosage adjustments were based on a defined schedule determined by the change in a subject's disease activity score, and steroid administration was discontinued as remission was achieved. Study treatment with 6-MP or placebo continued for 18 months.

RESULTS

Groups were comparable for age, sex, and site and activity of disease. In the 6-MP group, the duration of steroid use was shorter (P<0.001) and the cumulative steroid dose lower at 6, 12, and 18 months (P<0.01). Although remission was induced in 89% of both groups, only 9% of the remitters in the 6-MP group relapsed compared with 47% of controls (P = 0.007). Growth was comparable in both groups. No clinically significant adverse events occurred, although mild leukopenia and increases in aminotransferase activity were noted in the 6-MP group.

CONCLUSIONS

Addition of 6-MP to a regimen of corticosteroids significantly lessens the need for prednisone and improves maintenance of remission. 6-MP should be part of the initial treatment regimen for children with newly diagnosed moderate-to-severe CD.

Pediatric Inflammatory Bowel Disease

The combination of an unprecedented number of new therapeutic options (Fig. 1), along with new insights in how to optimize currently available therapies and advances in our understanding of disease pathogenesis, present many exciting new aspects to the management of patients with inflammatory bowel disease (IBD). Clinical management paradigms must evolve in parallel to keep pace with these advances. Traditional pediatric IBD regimens have underutilized combination therapies (Fig. 2) and immunomodulatory agents. Increased appreciation for steroid side effects is leading to a shift away from their inclusion in maintenance regimens. Immunomodulators are being introduced earlier in the course of disease for maintenance of remission and growth promotion. Recognition that the sole signs of active disease in children and adolescents may be growth and maturational delay, despite a relative lack of gastrointestinal symptoms, should prompt earlier, more aggressive interventions. When more potent, rapidly acting interventions such as infliximab, cyclosporine (CSA), or tacrolimus are considered, they should generally be co-administered with agents such as 6-mercaptopurine (6-MP) or azathioprine (AZA) for longer-term disease suppression.

High multidrug resistance (P-glycoprotein 170) expression in inflammatory bowel disease patients who fail medical therapy

BACKGROUND & AIMS

The multidrug resistance (MDR) gene codes for a drug efflux pump P-glycoprotein 170 (Pgp-170) expressed on the surface of lymphocytes and intestinal epithelial cells. Inflammatory bowel disease (IBD) poorly responsive to medical therapy may relate to MDR expression because glucocorticoids are known Pgp-170 substrates.

METHODS

Using flow cytometry, we measured peripheral blood lymphocyte (PBL) MDR in 153 IBD patients and 50 healthy volunteers, and assessed the relationship between PBL, mucosal intraepithelial lymphocyte (IEL), and mucosal epithelial cell (EC) MDR expression in a further 20 IBD patients and 19 controls.

RESULTS

Compared with controls, PBL MDR was significantly elevated in patients with Crohn's disease who required bowel resection for failed medical therapy (mean +/- SEM, 26.7 +/- 2.8 vs. 11.9 +/- 1.0; P <0.0001) and patients with ulcerative colitis who required proctocolectomy for failed medical therapy (20.3 +/- 2.5 vs. 11.9 +/- 1.0; P = 0.001). PBL MDR remained stable over time and was not influenced by disease activity or glucocorticoid therapy. Both PBL and mucosal MDR expression appeared independent of disease activity, and there was a significant correlation between PBL MDR expression and both IEL expression (r = 0.92; P < 0.0001) and EC expression (r = 0.54; P < 0.001).

CONCLUSIONS

PBL and mucosal MDR expression may play an important role in determining the response of IBD patients to glucocorticoid therapy.

Azathioprine or 6-mercaptopurine for inducing remission of Crohn's disease

OBJECTIVES

To determine the effectiveness of azathioprine and 6-mercaptopurine in inducing remission of active Crohn's disease.

SEARCH STRATEGY

Studies were selected using the MEDLINE data base (1966 - December 1997), abstracts from major gastrointestinal meetings and references from published articles and reviews. The Cochrane Controlled Trials Register and the Inflammatory Bowel Disease Review Group Trials Register was also searched.

SELECTION CRITERIA

Eight randomized placebo controlled trials of azathioprine and 6-mercaptopurine therapy in adult patients were identified: five dealt with active disease and three had multiple therapeutic arms.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers based on the intention to treat principle. Each study was given a quality score based on predetermined criteria. Extracted data were converted to 2X2 tables (response versus no response and antimetabolite versus placebo) and then synthesized into a summary test statistic using the pooled odds ratio and 95% confidence intervals as described by Cochran and Mantel and Haenszel ('Odds Ratio' in MetaView).

MAIN RESULTS

The odds ratio of a response to azathioprine or 6-mercaptopurine therapy compared with placebo in active Crohn's disease was 2.36 (95% CI 1.57-3.53). This corresponded to a number needed to treat of about 5 to observe an effect of therapy in one patient. When the two trials using 6-mercaptopurine in active disease were excluded from the analysis, the odds ratio of response was 2.04 (CI 1.24 - 3.35). Treatment >/= 17 weeks increased the odds ratio of a response to 2.51 (CI 1.63-3. 88). A steroid sparing effect was seen with an odds ratio of 3.86 (CI 2.14 - 6.96), corresponding to a number needed to treat of about 3 to observe steroid sparing in one patient. Adverse events requiring withdrawal from a trial, principally allergy, leukopenia, pancreatitis, and nausea were increased on therapy with an odds ratio of 3.01 (CI 1.30 - 6.96). The number needed to treat to observe one adverse event in one patient treated with azathioprine or 6-mercaptopurine was 14.

REVIEWER'S CONCLUSIONS

Azathioprine and 6-mercaptopurine are effective therapy for inducing remission in active Crohn's disease. The odds ratio of response increases after >/= 17 weeks of therapy, suggesting that there is a minimum length of time for a trial of azathioprine or 6-mercaptopurine therapy. Adverse events were more common among patients on therapy.

Combination therapy with oral tacrolimus (FK506) and azathioprine or 6-mercaptopurine for treatment-refractory Crohn's disease perianal fistulae

Our aim was to report the clinical experience with combination treatment using tacrolimus and either azathioprine (AZA) or 6-mercaptopurine (6MP) in patients with Crohn's disease (CD) perianal fistulae. The medical records of all patients with Crohn's disease perianal fistulae seen at the Mayo Clinic from 1996-1998 who were treated with tacrolimus were reviewed. Clinical response was classified as: complete response, partial response, and nonresponse. Eleven patients were treated with oral tacrolimus for a mean duration of 22 weeks. The initial oral dose of tacrolimus ranged from 0.15 to 0.31 mg/kg/day. Azathioprine or 6MP was continued in combination with tacrolimus in seven patients and initiated simultaneously with tacrolimus in four patients. All patients improved clinically, seven had a complete response, and four had a partial response. The mean time to initial improvement was 2.4 weeks, and the mean time to complete response was 12.2 weeks. The most frequent adverse events were nausea, paresthesias, nephrotoxicity, and tremor. Patients with nephrotoxicity had a significantly higher mean initial tacrolimus dose (0.31 mg/kg/day) compared with patients who did not have nephrotoxicity (0.25 mg/kg/day) (p = 0.035); however, there was not a statistically significant association between the starting dose or mean blood level and clinical response. Combination therapy with oral tacrolimus and AZA or 6MP may be effective treatment for CD perianal fistulae. Higher initial tacrolimus doses increase the risk of nephrotoxicity without improving clinical response.

Methotrexate in patients with Crohn's disease after 6-mercaptopurine

OBJECTIVE

The objective of this study was to describe the clinical outcome of children with Crohn's disease treated with subcutaneous methotrexate.

SUBJECTS/METHODS

Fourteen patients (10 boys) with extensive Crohn's disease diagnosed at a mean age of 10.6 +/- 3.6 years had previously received various medical therapies for 4.3 +/- 4.0 years. Because of the severity of their disease, 6-mercaptopurine had been introduced but discontinued because of the patients' failure to respond (n = 11) or the development of pancreatitis (n = 3). Subsequently, low-dose, weekly, subcutaneous methotrexate was initiated. Pediatric Crohn's Disease Activity Index scores and prednisone requirement were followed as outcome measures.

RESULTS

Overall, 9 (64%) of the 14 patients showed improvement, including 6 (55%) of 11 patients who had previously received an adequate trial of 6-mercaptopurine and all three patients who were intolerant of 6-mercaptopurine. Improvement in clinical and laboratory measures occurred by 4 weeks and were similar whether (n = 8) or not (n = 6) the dose of corticosteroids was increased before the start of subcutaneous methotrexate. Three patients were tapered from their initial methotrexate dose after the minimization of corticosteroids and remain well. One patient receiving daily corticosteroids died suddenly after acute onset of illness. Among patients responding, methotrexate was discontinued because of side effects (n = 2) or electively (n = 2). Of the latter two patients, one has resumed methotrexate after disease relapse, whereas the other patient has had a sustained remission.

CONCLUSIONS

Low-dose, weekly, subcutaneous methotrexate can induce remission in some pediatric patients with Crohn's disease who fail to adequately respond to other immunomodulator medications.

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.