The bioavailability of oral methotrexate in children with inflammatory bowel disease

Therapeutic role of methotrexate in pediatric Crohn's disease

The main role of therapy in Crohn's disease (CD) is to achieve long-term clinical remission, and to allow for normal growth and development of children. The immunomodulatory drugs used for the maintenance of remission in CD include thiopurines (azathioprine and 6-mercaptopurine) and methotrexate (MTX). Development of hepatosplenic T-cell lymphoma in some patients with inflammatory bowel disease, treated with thiopurines only or in combination with anti-tumor necrosis factor agents, resulted in a growing interest in the therapeutic application of MTX in children suffering from CD. This review summarizes the literature on the therapeutic role of MTX in children with CD. MTX is often administered as a second-line immunomodulator, and 1-year clinical remission was reported in 25-69% of children with CD after excluding for the use of thiopurines. Initial data on MTX effectiveness in mucosal healing, and as a first-line immunomodulator in pediatric patients with CD, are promising. A definite conclusion, however, may only be made on the basis of additional research with a larger number of subjects.

Use of Methotrexate in the Treatment of Inflammatory Bowel Diseases

Low-dose methotrexate (MTX) therapy is a well-recognized therapy for many inflammatory conditions such as rheumatoid arthritis, psoriatic arthritis, and psoriasis. More than 20 years ago, the clinical efficacy of MTX was also established for steroid dependent Crohn's disease, but it was never broadly adapted as a treatment modality. More recently, MTX is being increasingly used in the pediatric population with Crohn's disease, both as a single agent as well as a concomitant therapy with anti-tumor necrosis factor-alpha treatment. This review outlines important pharmacological aspects for the therapeutic application of MTX and the current status of MTX as mono- or combination-therapy in both pediatric and adult patients with inflammatory bowel disease including new results of MTX monotherapy in steroid dependent ulcerative colitis.

Uncertainty and variability in human exposure limits - a chemical-specific approach for ciprofloxacin and methotrexate

Human exposure limits (HELs) for chemicals with a toxicological threshold are traditionally derived using default assessment factors that account for variations in exposure duration, species sensitivity and individual sensitivity. The present paper elaborates a probabilistic approach for human hazard characterization and the derivation of HELs. It extends the framework for evaluating and expressing uncertainty in hazard characterization recently proposed by WHO-IPCS, i.e. by the incorporation of chemical-specific data on human variability in toxicokinetics. The incorporation of human variability in toxicodynamics was based on the variation between adverse outcome pathways (AOPs). Furthermore, sources of interindividual variability and uncertainty are propagated separately throughout the derivation process. The outcome is a two-dimensional human dose distribution that quantifies the population fraction exceeding a pre-selected critical effect level with an estimate of the associated uncertainty. This enables policy makers to set separate standards for the fraction of the population to be protected and the confidence level of the assessment. The main sources of uncertainty in the human dose distribution can be identified in order to plan new research for reducing uncertainty. Additionally, the approach enables quantification of the relative risk for specific subpopulations. The approach is demonstrated for two pharmaceuticals, i.e. the antibiotic ciprofloxacin and the antineoplastic methotrexate. For both substances, the probabilistic HEL is mainly influenced by uncertainty originating from: (1) the point of departure (PoD), (2) extrapolation from sub-acute to chronic toxicity and (3) interspecies extrapolation. However, when assessing the tails of the two-dimensional human dose distributions, i.e. the section relevant for the derivation of human exposure limits, interindividual variability in toxicodynamics also becomes important.

Methotrexate for the Management of Crohn's Disease in Children

OBJECTIVE

To review the literature evaluating methotrexate as a treatment option for Crohn's disease (CD) in pediatric patients.

DATA SOURCES

A search of PubMed electronic database (1966 to August 2015) and secondary resources was performed using the terms methotrexate, Crohn's, and inflammatory bowel disease. Other relevant articles cited within identified articles were also utilized.

STUDY SELECTION AND DATA EXTRACTION

Data sources were limited to English-language studies that included children less than 18 years of age. In total, 10 clinical studies met the criteria.

DATA SYNTHESIS

Awareness of the risk of hepatosplenic T-cell lymphoma associated with anti-tumor necrosis factor and thiopurine therapies has renewed interest in methotrexate to treat CD in children. According to data from 10 predominantly retrospective studies, children treated with oral or subcutaneous methotrexate once weekly had remission rates of 25% to 53% at 1 year. Adverse effects most often included nausea and vomiting, elevated liver function tests, headache, and hematological toxicity. The evidence to support methotrexate is limited by inconsistent study design and poorly described dosage regimens. It has been most frequently evaluated in patients with prior thiopurine exposure and has not been thoroughly evaluated as first-line therapy.

CONCLUSIONS

Based on results of retrospective studies, methotrexate is useful in the treatment of pediatric CD in those who fail thiopurine therapy. Remission rates with methotrexate are similar to those for thiopurine therapy, although no studies directly compare these agents. Although preliminary results are promising, prospective studies are needed to assess the use of methotrexate as initial first-line therapy in the pediatric CD population.

[Reccomendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on the use of methotrexate in inflammatory bowel disease]

Methotrexate is an immunosuppressant that may be useful in several clinical scenarios in inflammatory bowel disease. In this article, we review the available evidence in Crohn's disease and ulcerative colitis and establish general recommendations for its use in clinical practice. Although the available data are limited, it is very likely that methotrexate is underused because its effectiveness is underestimated and its toxicity is overestimated. Both in induction therapy and in maintenance of remission, methotrexate is useful in Crohn's disease. When prescribed in combination with biologic agents, immunogenicity is less frequent and consequently long-term response could potentially be improved. There are few published studies, but several data suggest that methotrexate could also be useful in ulcerative colitis. Although myelotoxicity and liver toxicity are well known risks, methotrexate is a drug that is well tolerated in many patients, even in the long term.

Retrospective cohort study of methotrexate use in the treatment of pediatric Crohn's disease

BACKGROUND

Methotrexate (MTX) use as an alternative to thiopurines in the treatment of Crohn's disease (CD) in children is increasing. This study was undertaken to assess safety and efficacy of MTX in children with CD.

METHODS

Patients treated with MTX with a minimum of 1-year follow-up were identified in the Pediatric IBD Collaborative Research Group Registry, a prospective inception cohort study started in 2002. The clinical efficacy and safety of MTX were analyzed retrospectively.

RESULTS

Two hundred ninety patients treated with MTX were identified. One hundred seventy-two patients received at least 3 months of MTX without thiopurine or biologicals and had ≥1 year of follow-up. Eighty-one of 172 patients (47%) received MTX as first immunomodulator (IMM), of which 22 (27%) achieved ≥12 months of sustained clinical remission without surgery, thiopurine, biologicals, or corticosteroids. Those receiving MTX as second IMM achieved similar remission rate (35%, P = not significant). Fourteen percent received MTX as first IMM in 2002 and 60% in 2010 (P = 0.005). Disease location did not affect outcomes. MTX doses were equivalent in both groups. Fifteen percent of patients developed an alanine aminotransferase >60 international units/liter and 12% developed a white blood cell <4000 cells per microliter while on MTX. Only 4% of these discontinued MTX completely. A small group of 6 centers, which contributed only about one-third of patients with CD in the registry, contributed nearly two-thirds of the patients receiving MTX (P < 0.001).

CONCLUSIONS

MTX use as first choice IMM is increasing in pediatric CD. MTX provided sustained clinical remission in nearly one-third of patients with minimal toxicity. There is large center-to-center variability in its use.

Hepatotoxicity caused by methotrexate therapy in children with inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

Methotrexate (MTX) is an immunomodulator used in pediatric inflammatory bowel disease (IBD) maintenance regimens. However, MTX use is associated with liver toxicity. We aimed to systematically review and meta-analyze the incidence of hepatotoxicity with MTX use among children with IBD.

METHODS

We searched MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases from 1946 to April 2013 for cohort studies and collected information about the study design, IBD treatment results, and hepatotoxicity. Pooled proportions of toxicity with 95% confidence interval (CI) were estimated using a random-effects model.

RESULTS

Twelve high-quality studies were included in this review. Fifty-seven of 457 patients treated with MTX developed varied degrees of abnormal liver biochemistry. The pooled proportion of patients with abnormal liver biochemistry was 10.2% (95% CI 5.4%-18.5%) across all studies included in the meta-analysis. Due to hepatotoxicity, dose reductions were required in 6.4% (95% CI 4.3%-9.5%), whereas 4.5% (95% CI 2.8%-7.2%) of patients required discontinuation.

CONCLUSIONS

Hepatotoxicity after the use of MTX among IBD patients was a relatively common event. Monitoring for hepatotoxicity is strongly recommended, as discontinuation of MTX may be necessary in a significant proportion of children.

Pharmacokinetic profiles for oral and subcutaneous methotrexate in patients with Crohn's disease

BACKGROUND

Methotrexate (MTX) is administered subcutaneously to Crohn's Disease (CD) patients. There are very few studies evaluating the use of oral (PO) MTX in CD. A drug and its pharmaceutical alternative are equivalent (bioequivalence) when the bioavailability of the alternative falls within 80-125% of the bioavailability of the standard (US Food and Drug Administration - FDA).

AIM

To compare the pharmacokinetic (PK) profiles of PO and subcutaneous (SC) MTX in CD patients to determine the bioequivalence of these two routes.

METHODS

Eleven patients received a PO and an SC MTX dose (25 mg) separated by one week over a two-week interval. Blood samples were collected at specified times over a 24-h period for each patient on two separate days. MTX plasma levels were obtained using sensitive mass spectrometry. Areas under the curve (AUC) were compared between the two routes.

RESULTS

The mean AUC values were 3375 ng/mL × h (PO MTX) and 3985 ng/mL × h (SC MTX). The mean AUC ratio (PO/SC) was 0.86 (0.62-1.08). This correlates with a relative PO bioavailability of 86% in comparison to SC. The 90% confidence interval for the mean AUC (PO/SC) ratio is (0.785, 0.929). There were no adverse events.

CONCLUSIONS

The mean MTX AUC (PO/SC) in these patients falls outside the 90% confidence interval for the bioequivalence limit. SC MTX is more bioavailable than PO MTX; however, the mean relative MTX bioavailability (PO/SC) nearly met the FDA bioequivalence standard and PO MTX could be proposed in responders who would prefer this route.

Concomitant therapy with methotrexate and anti-TNF-α in pediatric patients with refractory crohn's colitis: a case series

BACKGROUND

Crohn's colitis refractory to anti-tumor necrosis factor alpha (TNF-α) therapy is commonly seen in tertiary care centers for pediatric inflammatory bowel disease (IBD). We report our experience in managing pediatric refractory Crohn's colitis with concomitant use of methotrexate and anti-TNF-α therapy.

METHODS

We reviewed records from 2007 to 2010 at the Mayo Clinic pediatric IBD center. We included all patients with Crohn's disease (CD) failing anti-TNF-α therapy who then received concomitant methotrexate. The primary endpoint was clinical remission, defined as inactive disease in accordance with the short pediatric CD activity index (PCDAI). The secondary endpoint was last day of follow-up.

RESULTS

Fourteen patients with CD received concomitant methotrexate and anti-TNF-α treatment (age, mean [range], 15.7 [6-20] years; standard deviation [SD], 3.4 years). Mean age at diagnosis was 12.5 years (range, 3-17 years; SD, 3.83 years). The male-to-female ratio was 10:4. All patients had moderate to severe disease activity using the short PCDAI and had predominately Crohn's colitis. Twelve patients were previously treated with thiopurines (85.7%). Seven patients (50%) were in clinical remission within an average of 6 weeks postmethotrexate induction. Five patients (35.7%) experienced adverse events including nausea and headache, yet only one discontinued therapy due to adverse events. Infection with Clostridium difficile was common, complicating therapy in four patients (28.6%).

CONCLUSIONS

Concomitant use of methotrexate and anti-TNF-α therapy is a promising option for children with refractory Crohn's colitis.

A single-center experience with methotrexate after thiopurine therapy in pediatric Crohn disease

BACKGROUND AND AIM

Thiopurines are a common, effective means of maintaining remission in pediatric Crohn disease (CD). Methotrexate (MTX) may be considered for those intolerant of or unresponsive to thiopurines. The purpose of this study was to examine the effectiveness of MTX as maintenance therapy in patients previously treated with thiopurines.

PATIENTS AND METHODS

All of the patients at Nationwide Children's Hospital from 1998 to 2007 with an International Classification of Diseases code indicative of CD were identified. Patients with a diagnosis of CD, a history of prior thiopurine use, no current infliximab therapy, and at least 6 months of follow-up after MTX initiation were included. The primary outcome was defined as steroid-/infliximab-free remission determined by the physician global assessment at 6 and 12 months. Secondary outcomes included subsequent treatment with infliximab and/or corticosteroids, rate of discontinuation of MTX, and adverse events (AEs).

RESULTS

Twenty-seven patients (17 boys, 63%) with a mean age at diagnosis of 12.3 ± 0.7 years and mean disease duration of 1.49 ± 0.3 years were identified. Indications for MTX included nonresponse to thiopurines, AE, and poor adherence to thiopurines. At 6 and 12 months, 13 of 27 patients (48.1%) and 9 of 27 patients (33.3%), respectively, were in steroid-/infliximab-free remission. A total of 10 patients (37.0%) required infliximab therapy during the 12-month period and 5 patients discontinued MTX. Nausea was the most commonly reported AE. Transient transaminase elevation occurred in 4 patients and transient leukopenia in 2 patients.

CONCLUSIONS

MTX can be effective as maintenance therapy for patients with pediatric CD previously intolerant of or unresponsive to thiopurines; however, greater than one third of this cohort required escalation to antitumor necrosis factor therapy within 12 months following MTX initiation. MTX was well tolerated.

Methotrexate treatment in pediatric Crohn disease patients intolerant or resistant to purine analogues

BACKGROUND

Immunomodulatory drugs play a major role in maintaining remission and steroid sparing in children with Crohn disease. Although thiopurine agents are commonly used, unresponsiveness or intolerance to these drugs is common. The efficacy of methotrexate in maintenance of remission has been shown in adult Crohn disease; however, pediatric data are limited. Our goal was to evaluate the efficacy and safety of methotrexate in induction and maintenance of clinical remission in children with active Crohn disease who failed thiopurine treatment.

PATIENTS AND METHODS

In a retrospective multicenter study, efficacy of methotrexate in inducing and maintaining remission or response was assessed by Harvey-Bradshaw activity index, paediatric Crohn disease activity index and steroid use, in 25 children with Crohn disease, refractory or intolerant to thiopurine analogues.

RESULTS

Crohn disease was diagnosed at a mean age of 11.1 +/- 3.1 years and methotrexate was initiated at age 14.5 +/- 3.1 years. The median methotrexate dose was 12.5 mg/m2. Remission was achieved in 16 patients (64%), and response in 6 patients (24%). Out of 18 patients treated for longer than 6 months, 83% were in remission or response after 12 months of treatment. The mean duration of remission and response was 10.8 +/- 8.8 months. Steroid withdrawal was possible in 12/16 patients (75%) receiving steroids at methotrexate introduction. Adverse effects were observed in 6 patients (24%) including nausea and vomiting in 3, elevation of liver enzymes in 2 and pancreatitis in 1 patient.

CONCLUSIONS

Methotrexate is beneficial in maintaining remission and steroid-sparing treatment in children with Crohn disease following failure of thiopurine therapy.

Successful implementation of a nurse-led teaching programme to independently administer subcutaneous methotrexate in the community setting to children with Crohn's disease

BACKGROUND

Methotrexate is increasingly used as a third line immunosuppression agent in children with Crohn's disease (CD). Methotrexate is traditionally administered in the hospital setting.

AIM

To set up a nurse-led education programme to teach children/their parents to administer subcutaneous methotrexate in the community.

METHODS

All patients were given methotrexate over a 16-month period. Patient demographics including previous treatments were collected. A competency based teaching package was implemented by the inflammatory bowel disease nurse. Distances and travel times together with costings were calculated.

RESULTS

Thirty two patients (19 male; 13 female) with a median treatment age of 11.96 years (IQR 10.67-13.92) were studied. Thirty of 32 (17 children, 13 parents) were independently administering methotrexate. The median return journey distance to hospital was 23 miles (IQR 14.4-42.4) taking a median time of 52 min (IQR 41.0-73.5) for each injection. The total patient travel saving was £10,537 (average £730 per patient) and nursing time saving was £12,808 with home administration (total saving £23,345).

CONCLUSIONS

This paediatric study demonstrates that methotrexate injections can be given successfully in the majority (94%) of patients with CD independently in the community, resulting in significant time and money savings for patients and health professionals alike.

Specific considerations in the treatment of pediatric inflammatory bowel disease

Inflammatory bowel disease is one of the most prevalent chronic inflammatory disorders and commonly presents during childhood or adolescence. Occurring during a critical period of growth and development, pediatric Crohn's disease and ulcerative colitis require special consideration. Children often experience growth failure, malnutrition, pubertal delay and bone demineralization. Medical treatment must be optimized to promote clinical improvement and reverse growth failure with minimal toxicity. In addition to pharmacologic and surgical interventions, nutritional therapies play a vital role in the management of pediatric inflammatory bowel disease. This review will outline the epidemiology and clinical complications that are unique to pediatric inflammatory bowel disease, current trends, and recent advances in nutritional and pharmacologic treatment, and projected future therapeutic direction.

Special issues in pediatric inflammatory bowel disease

The incidence of pediatric inflammatory bowel disease (IBD) is rising and recent advances in diagnostics and therapeutics have improved the care provided to these children. There are distinguishing features worth noting between early onset and adult onset IBD. Physical and psychosocial development remains a critical target for the comprehensive management of pediatric IBD. Children are not just little adults and consideration must be given to the stages of development and how these stages impact disease presentation and management. The final stage will be the transition from pediatric care to that of adult oriented care and special consideration must be given to make this a successful process. This review highlights special considerations in the management of the child with IBD.

Methotrexate following unsuccessful thiopurine therapy in pediatric Crohn's disease

BACKGROUND

The thiopurines, azathioprine and 6-mercaptopurine, are traditional first-line immunomodulatory agents in adult and pediatric Crohn's disease, but the comparative efficacy and safety of methotrexate have seldom been examined. We report outcomes with methotrexate treatment in pediatric patients previously refractory to or intolerant of thiopurines.

METHODS

In a four-center, retrospective cohort study, efficacy of methotrexate in maintaining remission was assessed by PCDAI measurements, steroid use, and height velocity. Patients served as their own historical controls. Multivariable analysis controlled for route of methotrexate administration, reason for thiopurine discontinuation, baseline disease activity, and disease duration.

RESULTS

Forty-two percent of 60 children treated with methotrexate were in clinical remission without steroids at both 6 and 12 months. A strong steroid sparing effect was observed compared with the year prior to methotrexate (P<0.001). Success rates were similar in previously thiopurine-intolerant and refractory patients. Height velocity increased from -1.9 SDS to -0.14 SDS (P=0.004) in the year following therapy. In a median 3-yr follow-up, a third of the patients did not require escalation of therapy; the others required step-up therapy with infliximab or surgery. Eight children (13%) stopped methotrexate due to adverse events, including, most commonly, elevated liver enzymes, and one serious episode of sepsis.

CONCLUSION

Methotrexate appears effective in maintaining remission in pediatric Crohn's disease, when thiopurines have failed. Consideration should be given to its use earlier in pediatric treatment algorithms.

Role of methotrexate in the management of Crohn disease

BACKGROUND

The majority of children with Crohn disease (CD) are likely to need some form of immunomodulatory therapy to maintain remission and to avoid long-term corticosteroid usage. Although thiopurine agents are commonly used, some children are unresponsive or intolerant to these drugs. Biological agents like infliximab are being increasingly used in these circumstances, but long-term safety has yet to be established. Methotrexate has been shown to induce and maintain remission in CD in many adult studies, but pediatric data are limited. The present report describes our experience of using methotrexate in CD in children.

PATIENTS AND METHODS

All children with CD treated with methotrexate were identified by the departmental database. Case records were reviewed for site of disease, Pediatric Crohn Disease Activity Index, medications, time to achieve remission, duration of remission, and complications.

RESULTS

A total of 10 children received methotrexate, 7 of whom were female and 3 of whom were male. All of the children had colonic involvement and had active disease despite previous standard medical treatments. Seven children exhibited remission with methotrexate treatment. Median time to achieve remission was 12 weeks and median duration of remission was 21 months to the point of assessment. One child had transient increase of alanine aminotransferase levels and another developed neutropenia, which remitted with dose reduction. None needed discontinuation of methotrexate treatment.

CONCLUSIONS

Methotrexate is effective and well tolerated in children with CD. It should be considered in those patients who do not experience a remission with standard medications because it may avoid the use of biological agents and their potential uncertain long-term side effects.

Medical therapy for refractory pediatric Crohn's disease

Crohn's disease is a common indication for referral to pediatric gastroenterology. While most patients with Crohn's disease respond to standard induction therapy, steroid-refractory or steroid-dependent disease is a frequently encountered problem. This review discusses the data existing in both the adult and pediatric literature for medical therapy of refractory pediatric Crohn's disease.

Managing complicated Crohn's disease in children and adolescents

The natural history of Crohn's disease is characterized by recurrent exacerbations. A small, but significant, number of pediatric patients with Crohn's disease are resistant to standard medical therapies. The goal of therapy in pediatric patients is not only to achieve and maintain clinical remission, but also to promote growth, development and improve quality of life. All of this needs to be achieved within a relatively short window of opportunity, before growth and development deficiencies become permanent. The standard therapy for pediatric patients with Crohn's disease consists of 5-aminosalicylic-acid compounds, antibiotics and enteral nutrition. Enteral nutrition has an excellent adverse-effect profile and, in addition to its therapeutic effect, positively impacts growth and nutritional status. Immunomodulating medications, such as azathioprine, 6-mercaptopurine and methotrexate, are frequently used to maintain remission, and to treat corticosteroid-dependent and perianal disease. Recently, biologic treatment with the anti-tumor-necrosis-factor-alpha antibody infliximab has dramatically changed the therapeutic approach. The long-term safety of this therapy still needs to be established. Limited data are available on other biologic therapies, which, at this point in time, are considered experimental and are only available through clinical trials.