Evaluation of tolerance to mercaptopurine in patients with inflammatory bowel disease and gastrointestinal intolerance to azathioprine

BACKGROUND

Thiopurines such as azathioprine (AZA) and mercaptopurine (MP) are commonly utilized to treat inflammatory bowel disease (IBD). Their use is frequently restricted due to gastrointestinal intolerance (GI). Previous retrospective studies have reported that AZA-intolerant patients may benefit from a switch to MP; yet the effectiveness of this strategy has not been prospectively evaluated.

AIMS

To assess GI tolerance to MP in patients who are intolerant to AZA, and to identify clinical predictors of GI intolerance to AZA or MP.

METHODS

A prospective, observational, single-cohort study was performed in 92 thiopurine-naïve IBD patients. They were started on a 50mg dose of AZA and escalated to 2.5mg/kg per day by week 2. Those with GI intolerance were rechallenged with a 50% dose of AZA, after which another dose escalation attempt was made. If symptoms persisted, they were switched to MP.

RESULTS

Thirty (32.6%) of the recruited patients suffered from GI intolerance to AZA. Of these, 15 did not present recurrence of symptoms after rechallenge with lower doses. Of 15 intolerant patients, 14 were switched to MP. Within the MP cohort, 8 patients (57%) were also intolerant to MP, 5 (36%) had no symptoms, and 1 (7%) was lost to follow-up. Female gender was the only independent predictor of GI intolerance to AZA.

CONCLUSIONS

Up to half of the AZA-intolerant patients tolerated a 50% dose rechallenge that was successfully escalated. A switch to MP was tolerated in over a third of cases whom rechallenge failed. Our strategy (challenge-rechallenge-switch) achieved an overall GI tolerance to thiopurines in most of the patients.

Decreased Esophageal Sensitivity to Acid in Morbidly Obese Patients: A Cause for Concern?

Background/Aims

To evaluate esophageal sensitivity to acid between morbidly obese (MO) patients and non-MO controls with abnormal esophageal acid exposure.

Methods

We conducted a cross-sectional study of 58 patients: 30 MO (cases) and 28 non-MO (controls). Esophageal symptoms and esophageal sensitivity to 0.1 M hydrochloric acid solution (Bernstein test) were compared between MO and non-MO patients with a prior diagnosis of abnormal esophageal acid exposure.

Results

MO patients were less symptomatic than non-MO controls (14% vs 96%; odds ratio [OR], 0.006; 95% confidence interval [CI], 0.001 to 0.075; p=0.000). MO patients were more likely to present with decreased esophageal sensitivity to the instillation of acid than non-MO controls (57% vs 14%; OR, 8; 95% CI, 1.79 to 35.74; p=0.009). Subgroup analysis revealed no differences in esophageal sensitivity in MO patients with and without abnormal esophageal acid exposure (43% vs 31%; p=0.707).

Conclusions

Silent gastroesophageal reflux disease (GERD) is common among MO individuals, likely due to decreased esophageal sensitivity to acid. The absence of typical GERD symptoms in these patients may delay discovery of precancerous conditions, such as Barrett’s esophagus. We believe that these patients may require a more aggressive diagnostic work-up to rule out the presence of silent GERD.

Long-term safety and efficacy of budesonide in the treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic, relapsing, and remitting inflammatory disease involving the large intestine (colon). Treatment seeks to break recurrent inflammation episodes by inducing and maintaining remission. Historically, oral systemic corticosteroids played an important role in inducing remission of this chronic disease; however, their long-term use is limited and can lead to adverse events. Budesonide is a synthetic steroid with potent local anti-inflammatory effects and low systemic bioavailability due to high first-pass hepatic metabolism. Several studies have demonstrated oral budesonide’s usefulness in treating active mild to moderate ileocecal Crohn’s disease and microscopic colitis and in an enema formulation for left sided UC. However, there is limited information regarding oral budesonide’s efficacy in UC. A novel oral budesonide formulation using a multimatrix system (budesonide-MMX) to extend drug release throughout the colon has been developed recently and seems to be an effective treatment in active left sided UC patients. This article summarizes budesonide’s long-term safety and efficacy in treating UC.