-
Digestive and Liver Disease : Official... 2000The treatment of Crohn's disease and ulcerative colitis has evolved and has improved the quality of life of patients afflicted with these disorders. Immune modulators... (Review)
Review
The treatment of Crohn's disease and ulcerative colitis has evolved and has improved the quality of life of patients afflicted with these disorders. Immune modulators such as azathioprine and 6-mercaptopurine are an important class of medications used for the treatment of patients with inflammatory bowel disease. Controlled studies have demonstrated their efficacy in both induction and maintenance of remission in Crohn's disease, and similarly, for the induction and maintenance of remission in patients with ulcerative colitis. These agents have had an increasing importance in the management of steroid-resistant, steroid-dependent diseases, and fistulizing Crohn's disease. The primary limitations to these agents have been their slow onset of action and their side effect profile. Despite these limitations, these agents have demonstrated efficacy and have become paramount to the management of patients with these incurable potentially disabling disorders. The precise role of azathioprine/6-mercaptopurine, their limitations and their safety are reviewed in this paper.
Topics: Azathioprine; Clinical Trials as Topic; Drug Interactions; Humans; Immunosuppressive Agents; Inflammatory Bowel Diseases; Mercaptopurine; Neoplasms; Risk Factors
PubMed: 11057928
DOI: 10.1016/s1590-8658(00)80010-9 -
Alimentary Pharmacology & Therapeutics Apr 2016Azathioprine and mercaptopurine have a pivotal role in the treatment of inflammatory bowel disease (IBD). However, because of their complex metabolism and potential... (Review)
Review
BACKGROUND
Azathioprine and mercaptopurine have a pivotal role in the treatment of inflammatory bowel disease (IBD). However, because of their complex metabolism and potential toxicities, optimal use of biomarkers to predict adverse effects and therapeutic response is paramount.
AIM
To provide a comprehensive review focused on pharmacogenetics and pharmacokinetics for safe and effective thiopurine therapy in IBD.
METHODS
A literature search up to July 2015 was performed in PubMed using a combination of relevant MeSH terms.
RESULTS
Pre-treatment thiopurine S-methyltransferase typing plus measurement of 6-tioguanine nucleotides and 6-methylmercaptopurine ribonucleotides levels during treatment have emerged with key roles in facilitating safe and effective thiopurine therapy. Optimal use of these tools has been shown to reduce the risk of adverse effects by 3-7%, and to improve efficacy by 15-30%. For the introduction of aldehyde oxidase (AOX) into clinical practice, the association between AOX activity and AZA dose requirements should be positively confirmed. Inosine triphosphatase assessment associated with adverse effects also shows promise. Nucleoside diphosphate-linked moiety X-type motif 15 variants have been shown to predict myelotoxicity on thiopurines in East Asian patients. However, the impact of assessments of xanthine oxidase, glutathione S-transferase, hypoxanthine guanine phosphoribosyltransferase and inosine monophosphate dehydrogenase appears too low to favour incorporation into clinical practice.
CONCLUSIONS
Measurement of thiopurine-related enzymes and metabolites reduces the risk of adverse effects and improves efficacy, and should be considered part of standard management. However, this approach will not predict or avoid all adverse effects, and careful clinical and laboratory monitoring of patients receiving thiopurines remains essential.
Topics: Azathioprine; Humans; Inflammatory Bowel Diseases; Mercaptopurine; Methyltransferases; Pharmacogenetics; Thioinosine; Thionucleotides
PubMed: 26876431
DOI: 10.1111/apt.13559 -
Human Molecular Genetics Nov 2012Treatment-related toxicity can be life-threatening and is the primary cause of interruption or discontinuation of chemotherapy for acute lymphoblastic leukemia (ALL),...
Treatment-related toxicity can be life-threatening and is the primary cause of interruption or discontinuation of chemotherapy for acute lymphoblastic leukemia (ALL), leading to an increased risk of relapse. Mercaptopurine is an essential component of continuation therapy in all ALL treatment protocols worldwide. Genetic polymorphisms in thiopurine S-methyltransferase (TPMT) are known to have a marked effect on mercaptopurine metabolism and toxicity; however, some patients with wild-type TPMT develop toxicity during mercaptopurine treatment for reasons that are not well understood. To identify additional genetic determinants of mercaptopurine toxicity, a genome-wide analysis was performed in a panel of human HapMap cell lines to identify trans-acting genes whose expression and/or single-nucleotide polymorphisms (SNPs) are related to TPMT activity, then validated in patients with ALL. The highest ranking gene with both mRNA expression and SNPs associated with TPMT activity in HapMap cell lines was protein kinase C and casein kinase substrate in neurons 2 (PACSIN2). The association of a PACSIN2 SNP (rs2413739) with TPMT activity was confirmed in patients and knock-down of PACSIN2 mRNA in human leukemia cells (NALM6) resulted in significantly lower TPMT activity. Moreover, this PACSIN2 SNP was significantly associated with the incidence of severe gastrointestinal (GI) toxicity during consolidation therapy containing mercaptopurine, and remained significant in a multivariate analysis including TPMT and SLCO1B1 as covariates, consistent with its influence on TPMT activity. The association with GI toxicity was also validated in a separate cohort of pediatric patients with ALL. These data indicate that polymorphism in PACSIN2 significantly modulates TPMT activity and influences the risk of GI toxicity associated with mercaptopurine therapy.
Topics: Adaptor Proteins, Signal Transducing; Cell Line, Tumor; Child; Child, Preschool; Drug-Related Side Effects and Adverse Reactions; Female; Gastrointestinal Tract; Gene Expression; Genome-Wide Association Study; Genotype; HapMap Project; Humans; Male; Mercaptopurine; Methyltransferases; Polymorphism, Single Nucleotide; Precursor Cell Lymphoblastic Leukemia-Lymphoma
PubMed: 22846425
DOI: 10.1093/hmg/dds302 -
Therapeutic Drug Monitoring Dec 2017The use of thiopurines in the treatment of inflammatory bowel disease (IBD) can be optimized by the application of therapeutic drug monitoring. In this procedure,... (Review)
Review
The use of thiopurines in the treatment of inflammatory bowel disease (IBD) can be optimized by the application of therapeutic drug monitoring. In this procedure, 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurine (6-MMP) metabolites are monitored and related to therapeutic response and adverse events, respectively. Therapeutic drug monitoring of thiopurines, however, is hampered by several analytical limitations resulting in an impaired translation of metabolite levels to clinical outcome in IBD. Thiopurine metabolism is cell specific and requires nucleated cells and particular enzymes for 6-TGN formation. In the current therapeutic drug monitoring, metabolite levels are assessed in erythrocytes, whereas leukocytes are considered the main target cells of these drugs. Furthermore, currently used methods do not distinguish between active nucleotides and their unwanted residual products. Last, there is a lack of a standardized laboratorial procedure for metabolite assessment regarding the substantial instability of erythrocyte 6-TGN. To improve thiopurine therapy in patients with IBD, it is necessary to understand these limitations and recognize the general misconceptions in this procedure.
Topics: Antimetabolites; Azathioprine; Drug Monitoring; Humans; Inflammatory Bowel Diseases; Mercaptopurine; Thioguanine
PubMed: 29040228
DOI: 10.1097/FTD.0000000000000455 -
Alimentary Pharmacology & Therapeutics Sep 2006In the past 10-20 years, knowledge of both thiopurine pharmacology and -pharmacogenetics has been extended dramatically and used to develop new strategies to improve... (Review)
Review
BACKGROUND
In the past 10-20 years, knowledge of both thiopurine pharmacology and -pharmacogenetics has been extended dramatically and used to develop new strategies to improve efficacy and reduce toxicity.
AIM
To review thiopurine efficacy, toxicity, pharmacology, pharmacogenetics, interactions in patients with inflammatory bowel disease. Special attention was paid to new strategies for optimization of pharmacotherapy.
METHODS
To collect relevant scientific articles, a Pubmed search was performed from 1966 through January 2006 with the following key words (MeSH terms preferentially) in multiple combinations: 'azathioprine', '6-mercaptopurine', '6-MP', '6-thioguanine', '6-TG', 'thiopurine(s)', 'metabolites', 'level(s)', 'TDM', 'TMPT', 'ITPA', 'genotype(s)', 'phenotype(s)', 'inflammatory bowel disease', 'Crohn('s) disease', 'ulcerative colitis'.
RESULTS
Strategies for optimization of pharmacotherapy include therapeutic drug monitoring of thiopurine metabolites, geno- or phenotyping crucial enzymes in thiopurine metabolism like thiopurine S-methyltransferase and inosine triphosphate pyrophosphatase, and the use of thioguanine as such.
CONCLUSIONS
Thiopurine S-methyltransferase genotyping and therapeutic drug monitoring are useful instruments for individualizing thiopurine pharmacotherapy of inflammatory bowel disease. Inosine triphosphate pyrophosphatase genotyping may be helpful in case of unexplainable myelotoxicity. In case of azathioprine- or mercaptopurine-intolerance, thioguanine seems a promising alternative. However, more knowledge needs to be gathered about its potential hepatotoxicity.
Topics: Azathioprine; Drug Interactions; Gastrointestinal Agents; Genotype; Humans; Inflammatory Bowel Diseases; Mercaptopurine; Methyltransferases; Phenotype; Purines; Thioguanine; Treatment Outcome; Xanthine Oxidase
PubMed: 16918876
DOI: 10.1111/j.1365-2036.2006.02980.x -
World Journal of Gastroenterology Aug 2004Ulcerative colitis (UC) is an inflammatory destructive disease of the large intestine occurred usually in the rectum and lower part of the colon as well as the entire... (Review)
Review
Ulcerative colitis (UC) is an inflammatory destructive disease of the large intestine occurred usually in the rectum and lower part of the colon as well as the entire colon. Drug therapy is not the only choice for UC treatment and medical management should be as a comprehensive whole. Azulfidine, Asacol, Pentasa, Dipentum, and Rowasa all contain 5-aminosalicylic acid (5-ASA), which is the topical anti-inflammatory ingredient. Pentasa is more commonly used in treating Crohn's ileitis because Pentasa capsules release more 5-ASA into the small intestine than Asacol tablets. Pentasa can also be used for treating mild to moderate UC. Rowasa enemas are safe and effective in treating ulcerative proctitis and proctosigmoiditis. The sulfa-free 5-ASA agents (Asacol, Pentasa, Dipentum and Rowasa) have fewer side effects than sulfa-containing Azulfidine. In UC patients with moderate to severe disease and in patients who failed to respond to 5-ASA compounds, systemic (oral) corticosteroids should be used. Systemic corticosteroids (prednisone, prednisolone, cortisone, etc.) are potent and fast-acting drugs for treating UC, Crohn's ileitis and ileocolitis. Systemic corticosteroids are not effective in maintaining remission in patients with UC. Serious side effects can result from prolonged corticosteroid treatment. To minimize side effects, corticosteroids should be gradually reduced as soon as the disease remission is achieved. In patients with corticosteroid-dependent or unresponsive to corticosteroid treatment, surgery or immunomodulator is considered. Immunomodulators used for treating severe UC include azathioprine/6-MP, methotrexate, and cyclosporine. Integrated traditional Chinese and Western medicine is safe and effective in maintaining remission in patients with UC.
Topics: Adrenal Cortex Hormones; Anti-Inflammatory Agents, Non-Steroidal; Anti-Ulcer Agents; Colitis, Ulcerative; Cyclosporine; Humans; Immunosuppressive Agents; Medicine, Chinese Traditional; Mercaptopurine
PubMed: 15285010
DOI: 10.3748/wjg.v10.i16.2311 -
Drug Safety May 2021Inflammatory bowel disease (IBD) frequently requires chronic immunosuppressive treatment and active involvement from patients during treatment decision making....
INTRODUCTION
Inflammatory bowel disease (IBD) frequently requires chronic immunosuppressive treatment and active involvement from patients during treatment decision making. Information about the risk of developing adverse drug reactions (ADRs) to IBD therapies is required in this process.
OBJECTIVE
The aim of this study was to describe the ADRs reported in IBD patients from real-world data, using the Dutch nationwide IBDREAM registry, and compare the occurrence and cumulative incidences with the Summary of Product Characteristics (SmPC) of the associated drugs.
METHODS
In this retrospective multicentre study, ADRs related to IBD medication were assessed. Only reports associated with the use of drugs used for the maintenance treatment of IBD were included. All ADRs were verified by healthcare professionals and coded by trained pharmacovigilance assessors.
RESULTS
In total, 3080 ADRs were reported in 1179 patients. Twenty-three new drug-ADR associations related to the use of azathioprine, mercaptopurine, infliximab, oral mesalamine and thioguanine were reported in the IBDREAM registry that were not mentioned in the corresponding SmPCs. The most frequently reported new association was pyrexia for azathioprine (3.1%) and mercaptopurine (4.9%). In addition, there were seven ADRs with a higher cumulative incidence in IBDREAM compared with the SmPC, and included, among others, arthralgia during mercaptopurine use (2.5%), and diarrhoea (1.4%), alopecia (1.2%) and infections (1.6%) during azathioprine use.
CONCLUSIONS
Based on real-world data, ADR reporting demonstrated new ADRs and higher incidences of ADRs to IBD therapies. This information will contribute to drug safety by updating the SmPCs, allowing better risk assessment and communication towards patients.
Topics: Adverse Drug Reaction Reporting Systems; Azathioprine; Drug-Related Side Effects and Adverse Reactions; Humans; Inflammatory Bowel Diseases; Mercaptopurine; Pharmacovigilance; Registries; Retrospective Studies
PubMed: 33538994
DOI: 10.1007/s40264-021-01045-3 -
Current Drug Metabolism 2015Induced pluripotent stem cells (iPSC) can be produced from adult cells by transfecting them with a definite set of pluripotency-associated genes. Under adequate growth... (Review)
Review
Induced pluripotent stem cells (iPSC) can be produced from adult cells by transfecting them with a definite set of pluripotency-associated genes. Under adequate growth conditions and stimulation iPSC can differentiate to almost every somatic lineage in the body. Patients' derived iPSC are an innovative model to study mechanisms of adverse drug reactions in individual patients and in cell types that cannot be easily obtained from human subjects. Proof-of concept studies with known toxicants have been performed for liver, cardiovascular and central nervous system cells: neurons obtained from iPSC have been used to elucidate the mechanism of chemotherapy-induced peripheral neuropathy by evaluating the effects of neurotoxic drugs such as vincristine. However, no study has been performed yet on pancreatic tissue and drug induced pancreatitis. Thiopurines (azathioprine and mercaptopurine) are immunosuppressive antimetabolite drugs, commonly used to treat Crohn's disease. About 5% of Crohn's disease patients treated with thiopurines develop pancreatitis, a severe idiosyncratic adverse event; these patients have to stop thiopurine administration and may require medical treatment, with significant personal and social costs. Molecular mechanism of thiopurine induced pancreatitis (TIP) is currently unknown and no fully validated biomarker is available to assist clinicians in preventing this adverse event. Hence, in this review we have reflected upon the probable research applications of exocrine pancreatic cells generated from patient specific iPS cells. Such pancreatic cells can provide excellent insights into the molecular mechanism of TIP. In particular three hypotheses on the mechanism of TIP could be explored: drug biotransformation, innate immunity and adaptative immunity.
Topics: Adaptive Immunity; Animals; Azathioprine; Humans; Immunosuppressive Agents; Induced Pluripotent Stem Cells; Mercaptopurine; Pancreatitis; Predictive Value of Tests; Risk Factors
PubMed: 26526832
DOI: 10.2174/1389200216666151103120220 -
Journal of Gastroenterology Feb 2018The thiopurine drugs 6-mercaptopurine (6-MP) and azathiopurine (AZA) are widely used to treat inflammatory bowel disease. However, the incidence of adverse reactions is... (Review)
Review
The thiopurine drugs 6-mercaptopurine (6-MP) and azathiopurine (AZA) are widely used to treat inflammatory bowel disease. However, the incidence of adverse reactions is high, particularly in Asia, and the mechanisms of toxicity in Asian populations remain unclear. Thiopurine S-methyltransferase (TPMT) is a well-known enzyme that inactivates AZA or 6-MP through methylation and is one of the few pharmacogenetic predictors used in clinical settings in Western countries. Individuals carrying TPMT-deficient genetic variants require reduced drug doses, but this treatment modification is are not applicable to East Asian populations. Several genes code thiopurine-metabolizing enzymes, including TPMT, multidrug-resistance protein 4, and inosine triphosphatase. These genes have been studied as candidate pharmacogenetic markers; however, it remains unclear why Asian populations seem to be more intolerant than other ethnic groups to a full dose of thiopurines. A genome-wide association approach to identify Asian-specific pharmacogenetic markers in Korean patients with Crohn's disease revealed that a non-synonymous single nucelotide polymorphism in nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15) which causes p.Arg139Cys was strongly associated with thiopurine-induced early leukopenia. Six common haplotypes of NUDT15 were reported, and five variants showed medium-to-low enzyme activities, compared with the wild haplotype. NUDT15 hydrolyzes the thiopurine active metabolites 6-thio-GTP and 6-thio-dGTP; variants of NUDT15 had lower enzyme activities, causing higher levels of thiopurine active metabolites, resulting in thiopurine-induced leukopenia. In clinical application, NUDT15 genotyping is a good candidate for predicting thiopurine toxicity in East Asian populations. However, the association of NUDT15 diplotypes with thiopurine toxicity remains unclear. Further analyses with large cohorts to confirm the clinical effects of each haplotype are planned.
Topics: Asian People; Gastrointestinal Agents; Genotype; Humans; Inflammatory Bowel Diseases; Mercaptopurine; Pyrophosphatases
PubMed: 29192347
DOI: 10.1007/s00535-017-1416-0 -
World Journal of Gastroenterology Aug 2011Misconceptions are common in the care of patients with inflammatory bowel disease (IBD). In this paper, we state the most commonly found misconceptions in clinical...
Misconceptions are common in the care of patients with inflammatory bowel disease (IBD). In this paper, we state the most commonly found misconceptions in clinical practice and deal with the use of 5-aminosalicylates and thiopurines, to review the related scientific evidence, and make appropriate recommendations. Prevention of errors needs knowledge to avoid making such errors through ignorance. However, the amount of knowledge is increasing so quickly that one new danger is an overabundance of information. IBD is a model of a very complex disease and our goal with this review is to summarize the key evidence for the most common daily clinical problems. With regard to the use of 5-aminosalicylates, the best practice may to be consider abandoning the use of these drugs in patients with small bowel Crohn' s disease. The combined approach with oral plus topical 5-aminosalicylates should be the first-line therapy in patients with active ulcerative colitis; once-daily treatment should be offered as a first choice regimen due to its better compliance and higher efficacy. With regard to thiopurines, they seem to be as effective in ulcerative colitis as in Crohn' s disease. Underdosing of thiopurines is a form of undertreatment. Thiopurines should probably be continued indefinitely because their withdrawal is associated with a high risk of relapse. Mercaptopurine is a safe alternative in patients with digestive intolerance or hepatotoxicity due to azathioprine. Finally, thiopurine methyltransferase (TPMT) screening cannot substitute for regular monitoring because the majority of cases of myelotoxicity are not TPMT-related.
Topics: Anti-Inflammatory Agents, Non-Steroidal; Azathioprine; Humans; Immunosuppressive Agents; Inflammatory Bowel Diseases; Mercaptopurine; Mesalamine
PubMed: 21941413
DOI: 10.3748/wjg.v17.i30.3467