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Expert Review of Gastroenterology &... Feb 2015Immune modulating drugs such as thiopurines (azathioprine and 6-mercaptopurine) and methotrexate has been a mainstay for treatment of inflammatory bowel disease (IBD)... (Review)
Review
Immune modulating drugs such as thiopurines (azathioprine and 6-mercaptopurine) and methotrexate has been a mainstay for treatment of inflammatory bowel disease (IBD) for decades. However, despite widely used in IBD, questions still remain concerning the most rational treatment regimens of these agents. Results from a range of recent studies necessitate increased awareness on how to best use these potent drugs in the clinic. As controversy still remains regarding the most appropriate use of immunomodulators, this review is based on scrutinizing the current literature, with emphasis on randomized controlled trials and Cochrane reviews, focusing on aspects that can lead to optimal and evidence-based thiopurine and methotrexate treatment strategies in IBD.
Topics: Azathioprine; Humans; Immunologic Factors; Immunomodulation; Inflammatory Bowel Diseases; Mercaptopurine; Methotrexate; Treatment Outcome
PubMed: 25101818
DOI: 10.1586/17474124.2014.945914 -
The Cochrane Database of Systematic... May 2016Maintenance of remission is a major issue in inflammatory bowel disease. In ulcerative colitis, the evidence for the effectiveness of azathioprine and 6-mercaptopurine... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Maintenance of remission is a major issue in inflammatory bowel disease. In ulcerative colitis, the evidence for the effectiveness of azathioprine and 6-mercaptopurine for the maintenance of remission is still controversial.
OBJECTIVES
To assess the effectiveness and safety of azathioprine and 6-mercaptopurine for maintaining remission of ulcerative colitis.
SEARCH METHODS
The MEDLINE, EMBASE and Cochrane Library databases were searched from inception to 30 July 2015. Both full randomized controlled trials and associated abstracts were included.
SELECTION CRITERIA
Randomized controlled trials of at least 12 months duration that compared azathioprine or 6-mercaptopurine with placebo or standard maintenance therapy (e.g. mesalazine) were included.
DATA COLLECTION AND ANALYSIS
Two authors independently extracted data using standard forms. Disagreements were solved by consensus including a third author. Study quality was assessed using the Cochrane risk of bias tool. The primary outcome was failure to maintain clinical or endoscopic remission. Secondary outcomes included adverse events and withdrawal due to adverse events. Analyses were performed separately by type of control (placebo, or active comparator). Pooled risk ratios were calculated based on the fixed-effect model unless heterogeneity was shown. The GRADE approach was used to assess the overall quality of evidence for pooled outcomes.
MAIN RESULTS
Seven studies including 302 patients with ulcerative colitis were included in the review. The risk of bias was high in three of the studies due to lack of blinding. Azathioprine was shown to be significantly superior to placebo for maintenance of remission. Fourty-four per cent (51/115) of azathioprine patients failed to maintain remission compared to 65% (76/117) of placebo patients (4 studies, 232 patients; RR 0.68, 95% CI 0.54 to 0.86). A GRADE analysis rated the overall quality of the evidence for this outcome as low due to risk of bias and imprecision (sparse data). Two trials that compared 6-mercaptopurine to mesalazine, or azathioprine to sulfasalazine showed significant heterogeneity and thus were not pooled. Fifty per cent (7/14) of 6-mercaptopurine patients failed to maintain remission compared to 100% (8/8) of mesalazine patients (1 study, 22 patients; RR 0.53, 95% CI 0.31 to 0.90). Fifty-eight per cent (7/12) of azathioprine patients failed to maintain remission compared to 38% (5/13) of sulfasalazine patients (1 study, 25 patients; RR 1.52, 95% CI 0.66 to 3.50). One small study found that 6-mercaptopurine was superior to methotrexate for maintenance of remission. In the study, 50% (7/14) of 6-mercaptopurine patients and 92% (11/12) of methotrexate patients failed to maintain remission (1 study, 26 patients; RR 0.55, 95% CI 0.31 to 0.95). One very small study compared azathioprine with cyclosporin and found that there was no significant difference between patients failing remission on azathioprine (50%, 4/8) or cyclosporin (62.5%, 5/8) (1 study, 16 patients, RR 0.80 95% CI 0.33 to 1.92). When placebo-controlled studies were pooled with aminosalicylate-comparator studies to assess adverse events, there was no statistically significant difference between azathioprine and control in the incidence of adverse events. Nine per cent (11/127) of azathioprine patients experienced at least one adverse event compared to 2% (3/130) of placebo patients (5 studies, 257 patients; RR 2.82, 95% CI 0.99 to 8.01). Patients receiving azathioprine were at significantly increased risk of withdrawing due to adverse events. Eight per cent (8/101) of azathioprine patients withdrew due to adverse events compared to 0% (0/98) of control patients (5 studies, 199 patients; RR 5.43, 95% CI 1.02 to 28.75). Adverse events related to study medication included acute pancreatitis (3 cases, plus 1 case on cyclosporin) and significant bone marrow suppression (5 cases). Deaths, opportunistic infection or neoplasia were not reported.
AUTHORS' CONCLUSIONS
Azathioprine therapy appears to be more effective than placebo for maintenance of remission in ulcerative colitis. Azathioprine or 6-mercaptopurine may be effective as maintenance therapy for patients who have failed or cannot tolerate mesalazine or sulfasalazine and for patients who require repeated courses of steroids. More research is needed to evaluate superiority over standard maintenance therapy, especially in the light of a potential for adverse events from azathioprine. This review updates the existing review of azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis which was published in the Cochrane Library (September 2012).
Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Antimetabolites; Azathioprine; Colitis, Ulcerative; Humans; Maintenance Chemotherapy; Mercaptopurine; Mesalamine; Randomized Controlled Trials as Topic; Secondary Prevention; Sulfasalazine
PubMed: 27192092
DOI: 10.1002/14651858.CD000478.pub4 -
Current Drug Metabolism 2016Thiopurine antimetabolites are important agents for the treatment of severe diseases, such as acute lymphoblastic leukemia and inflammatory bowel disease. Their... (Review)
Review
BACKGROUND
Thiopurine antimetabolites are important agents for the treatment of severe diseases, such as acute lymphoblastic leukemia and inflammatory bowel disease. Their pharmacological actions depend on biotransformation into active thioguanine-nucleotides; intracellular metabolism is mediated by enzymes of the salvage pathway of nucleotide synthesis and relies on polymorphic enzymes involved in thiopurines' catabolism such as thiopurine-S-methyl transferase. Given the enzymes involved in thiopurines' metabolism, it is reasonable to hypothesize that these drugs are able to induce significant oxidative stress conditions, possibly altering their pharmacological activity.
METHODS
A systemic search of peer-reviewed scientific literature in bibliographic databases has been carried out. Both clinical and preclinical studies as well as mechanistic studies have been included to shed light on the role of oxidative stress in thiopurines' pharmacological effects.
RESULTS
Sixty-nine papers were included in our review, allowing us to review the contribution of oxidative stress in the pharmacological action of thiopurines. Thiopurines are catabolized in the liver by xanthine oxidase, with potential production of reactive oxidative species and azathioprine is converted into mercaptopurine by a reaction with reduced glutathione, that, in some tissues, may be facilitated by glutathione- S-transferase (GST). A clear role of GSTM1 in modulating azathioprine cytotoxicity, with a close dependency on superoxide anion production, has been recently demonstrated. Interestingly, recent genome-wide association studies have shown that, for both azathioprine in inflammatory bowel disease and mercaptopurine in acute lymphoblastic leukemia, treatment effects on patients' white blood cells are related to variants of a gene, NUDT15, involved in biotransformation of oxidated nucleotides.
CONCLUSIONS
Basing on previous evidences published in literature, oxidative stress may contribute to thiopurine effects in significant ways that, however, are still not completely elucidated.
Topics: Animals; Antimetabolites; Azathioprine; Biotransformation; Glutathione; Glutathione Transferase; Humans; Liver; Mercaptopurine; Metabolic Detoxication, Phase II; Oxidative Stress; Pharmacogenetics; Polymorphism, Single Nucleotide; Pyrophosphatases; Reactive Oxygen Species; Risk Factors; Xanthine Oxidase
PubMed: 26935390
DOI: 10.2174/1389200217666160303104153 -
Journal of Crohn's & Colitis Jan 2019
Topics: DNA; Humans; Inflammatory Bowel Diseases; Male; Mercaptopurine; Spermatozoa
PubMed: 30272119
DOI: 10.1093/ecco-jcc/jjy134 -
Pediatric Research Jan 2021Mercaptopurine-induced neutropenia can interrupt chemotherapy and expose patients to infection during childhood acute lymphoblastic leukemia (ALL) treatment. Previously,...
BACKGROUND
Mercaptopurine-induced neutropenia can interrupt chemotherapy and expose patients to infection during childhood acute lymphoblastic leukemia (ALL) treatment. Previously, six candidate gene variants associated with mercaptopurine intolerance were reported. Herein, we investigated the association between the mean tolerable dose of mercaptopurine and these genetic variants in Taiwanese patients.
METHODS
In total, 294 children with ALL were treated at the National Taiwan University Hospital from April 1997 to December 2017. Germline variants were analyzed for NUDT15, SUCLA2, TPMT, ITPA, PACSIN2, and MRP4. Mean daily tolerable doses of mercaptopurine in the continuation phase of treatment were correlated with these genetic variants.
RESULTS
Mercaptopurine intolerance was significantly associated with polymorphisms in NUDT15 (P value < 0.0001). Patients with SUCLA2 variants received lower mercaptopurine doses (P value = 0.0119). The mean mercaptopurine doses did not differ among patients with TPMT, ITPA, MRP4, and PACSIN2 polymorphisms (P value = 0.9461, 0.5818, and 0.7951, respectively). After multivariable linear regression analysis, only NUDT15 variants retained their clinically significant correlation with mercaptopurine intolerance (P value < 0.0001).
CONCLUSION
In this cohort, the major genetic determinant of mercaptopurine intolerance was NUDT15 in Taiwanese patients.
IMPACT
NUDT15 causes mercaptopurine intolerance in children with ALL. The NUDT15 variant is a stronger predictor of mercaptopurine intolerance than TPMT in a Taiwanese cohort. This finding is similar with studies performed on Asian populations rather than Caucasians. Pre-emptive genotyping of the patients' NUDT15 before administering mercaptopurine may be more helpful than genotyping TPMT in Asians.
Topics: Antimetabolites, Antineoplastic; Humans; Mercaptopurine; Methyltransferases; Neutropenia; Pharmacogenomic Variants; Polymorphism, Single Nucleotide; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Pyrophosphatases; Retrospective Studies; Risk Assessment; Risk Factors; Taiwan
PubMed: 32221476
DOI: 10.1038/s41390-020-0868-8 -
Alimentary Pharmacology & Therapeutics Jun 2020Thiopurines in combination with glucocorticoids are used as first-line, second-line and maintenance therapies in autoimmune hepatitis and opportunities exist to improve... (Review)
Review
BACKGROUND
Thiopurines in combination with glucocorticoids are used as first-line, second-line and maintenance therapies in autoimmune hepatitis and opportunities exist to improve and expand their use.
AIMS
To describe the metabolic pathways and key factors implicated in the efficacy and toxicity of the thiopurine drugs and to indicate the opportunities to improve outcomes by monitoring and manipulating metabolic pathways, individualising dosage and strengthening the response.
METHODS
English abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and secondary and tertiary bibliographies were developed.
RESULTS
Thiopurine methyltransferase activity and 6-tioguanine (6-thioguanine) nucleotide levels influence drug efficacy and safety, and they can be manipulated to improve treatment response and prevent myelosuppression. Methylated thiopurine metabolites are associated with hepatotoxicity, drug intolerance and nonresponse and their production can be reduced or bypassed. Universal pre-treatment assessment of thiopurine methyltransferase activity and individualisation of dosage to manipulate metabolite thresholds could improve outcomes. Early detection of thiopurine resistance by metabolite testing, accurate estimations of drug onset and strength by surrogate markers and adjunctive use of allopurinol could improve the management of refractory disease. Dose-restricted tioguanine (thioguanine) could expand treatment options by reducing methylated metabolites, increasing the bioavailability of 6-tioguanine nucleotides and ameliorating thiopurine intolerance or resistance.
CONCLUSIONS
The efficacy and safety of thiopurines in autoimmune hepatitis can be improved by investigational efforts that establish monitoring strategies that allow individualisation of dosage and prediction of outcome, increase bioavailability of the active metabolites and demonstrate superiority to alternative agents.
Topics: Allopurinol; Azathioprine; Drug-Related Side Effects and Adverse Reactions; Guanine Nucleotides; Hepatitis, Autoimmune; Humans; Inflammatory Bowel Diseases; Mercaptopurine; Purines; Quality Improvement; Thioguanine; Thionucleotides; Treatment Outcome
PubMed: 32363674
DOI: 10.1111/apt.15743 -
World Journal of Gastroenterology Oct 2021Thiopurines are immunomodulators used in the treatment of acute lymphoblastic leukemia and inflammatory bowel diseases. Adverse reactions to these agents are one of the...
Thiopurines are immunomodulators used in the treatment of acute lymphoblastic leukemia and inflammatory bowel diseases. Adverse reactions to these agents are one of the main causes of treatment discontinuation or interruption. Myelosuppression is the most frequent adverse effect; however, approximately 5%-20% of patients develop gastrointestinal toxicity. The identification of biomarkers able to prevent and/or monitor these adverse reactions would be useful for clinicians for the proactive management of long-term thiopurine therapy. In this editorial, we discuss evidence supporting the use of , , and genes, in addition to and as possible biomarkers for thiopurine-related gastrointestinal toxicity.
Topics: Azathioprine; Biomarkers; Humans; Immunologic Factors; Mercaptopurine; Methyltransferases; Pyrophosphatases
PubMed: 34720526
DOI: 10.3748/wjg.v27.i38.6348 -
The Cochrane Database of Systematic... Oct 2016The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease have been... (Meta-Analysis)
Meta-Analysis Review
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.
Topics: Adult; Antimetabolites; Azathioprine; Crohn Disease; Glucocorticoids; Humans; Immunosuppressive Agents; Induction Chemotherapy; Infliximab; Mercaptopurine; Mesalamine; Prednisone; Randomized Controlled Trials as Topic; Sulfasalazine; Withholding Treatment
PubMed: 27783843
DOI: 10.1002/14651858.CD000545.pub5 -
Revista Espanola de Enfermedades... Jan 2017Data about use and effectiveness of mercaptopurine in inflammatory bowel disease are relatively limited. (Observational Study)
Observational Study
BACKGROUND
Data about use and effectiveness of mercaptopurine in inflammatory bowel disease are relatively limited.
AIMS
To assess the possible therapeutic indications, efficacy and safety of mercaptopurine as an alternative to azathioprine in inflammatory bowel disease.
METHODS
Retrospective observational study in patients treated with mercaptopurine in a total cohort of 1,574 patients with inflammatory bowel disease.
RESULTS
One hundred and fifty-two patients received mercaptopurine, 15.7% of these patients as an initial thiopurine, 5.3% after azathioprine failure, and 79% after azathioprine intolerance. In 52.6% of patients (n = 80), adverse effects of mercaptopurine occurred, resulting in withdrawal in 49 of them. Mercaptopurine was effective in 39% of cases (95% CI 31-48%). In the remaining patients, failure was due mainly to withdrawal due to side effects (55.1%) and therapeutic step-up (33.7%). The average total time of mercaptopurine exposure was 36 months (IQR: 2-60). Myelotoxicity with mercaptopurine was more common in patients with intermediate TPMT activity than in those with normal activity (p = 0.046).
CONCLUSIONS
In our setting, mercaptopurine is primarily used as a rescue therapy in patients with azathioprine adverse effects. This could explain its modest efficacy and the high rate of adverse effects. However, this drug is still an alternative in this group of patients, before a therapeutic step-up to biologics is considered.
Topics: Adult; Aged; Azathioprine; Cohort Studies; Crohn Disease; Female; Humans; Immunosuppressive Agents; Inflammatory Bowel Diseases; Male; Mercaptopurine; Middle Aged; Retrospective Studies; Treatment Failure
PubMed: 27809554
DOI: 10.17235/reed.2016.4546/2016 -
Journal of Clinical Gastroenterology Jan 2017The objective of the study was to define the clinical, biochemical, and histologic features of liver injury from thiopurines.
OBJECTIVE
The objective of the study was to define the clinical, biochemical, and histologic features of liver injury from thiopurines.
BACKGROUND
Azathioprine (Aza) and 6-mercaptopurine (6-MP) can cause liver injury, but no large series exist.
METHODS
Clinical and laboratory data and 6-month outcomes of patients with thiopurine hepatotoxicity from the Drug-Induced Liver Injury Network Prospective Study were analyzed.
RESULTS
Twenty-two patients were identified, 12 due to Aza and 10 due to 6-MP, with a median age of 55 years; the majority were female (68%). Inflammatory bowel disease was the indication in 55%, and the median thiopurine dose was 150 (range, 25 to 300) mg daily. The median latency to onset was 75 (range, 3 to 2584) days. Injury first arose after a dose escalation in 59% of patients, the median latency after dose increase being 44 (range, 3 to 254) days. At onset, the median alanine aminotransferase level was 210 U/L, alkaline phosphatase was 151 U/L, and bilirubin was 7.4 mg/dL (peak, 13.4 mg/dL). There were no major differences between Aza and 6-MP cases, but anicteric cases typically had nonspecific symptoms and a hepatocellular pattern of enzyme elevations, whereas icteric cases experienced cholestatic hepatitis with modest enzyme elevations in a mixed pattern. One patient with preexisting cirrhosis required liver transplantation; all others resolved clinically. One patient still had moderate alkaline phosphatase elevations 2 years after onset.
CONCLUSIONS
Nearly three-quarters of patients with thiopurine-induced liver injury present with self-limited, cholestatic hepatitis, typically within 3 months of starting or a dose increase. The prognosis is favorable except in patients with preexisting cirrhosis.
Topics: Adolescent; Adult; Aged; Alanine Transaminase; Alkaline Phosphatase; Azathioprine; Bilirubin; Chemical and Drug Induced Liver Injury; Child; Cholestasis; Databases, Factual; Female; Humans; Inflammatory Bowel Diseases; Male; Mercaptopurine; Middle Aged; Prospective Studies; Time Factors; Young Adult
PubMed: 27648552
DOI: 10.1097/MCG.0000000000000568