Navigating methotrexate toxicity: Examining the therapeutic roles of folinic acid and glucarpidase.

Methotrexate (MTX) toxicity varies depending on factors such as dosing frequency (acute or repeated), dosage (low or high) and the administration route (oral, parenteral or intrathecal). Renal impairment can trigger or exacerbate MTX toxicity. Acute oral low-dose MTX (LDMTX) overdoses seldom lead to toxicity due to the saturable maximal bioavailable dose, but toxicity risks increase with repeated low doses (>3 days), high-dose MTX (HDMTX) or intrathecal poisoning. Folinic acid shares MTX transporters in the gut and cells and bypasses the MTX-induced dihydrofolate reductase inhibition. The required folinic acid dosage differs for low-dose and high-dose MTX toxicities. Acute LDMTX poisoning rarely requires folinic acid, while chronic LDMTX poisoning needs low-dose folinic acid until cellular function is restored. In HDMTX toxicities, early intravenous folinic acid administration is recommended, with dose and duration being guided by MTX concentrations and clinical improvement. In intrathecal MTX poisoning, folinic acid should be administered intravenously. Glucarpidase, a recombinant bacterial enzyme, has a high affinity for MTX and folate analogues in the intravascular or intrathecal systems. It decreases serum MTX concentrations by 90%-95% within 15 min. Its primary indication is for intrathecal MTX poisoning. It is rarely indicated in HDMTX toxicity unless patients have renal injury. However, there is no literature evidence supporting its use in HDMTX poisoning. Its use is limited by its significant cost and lack of availability. Haemodialysis can be potentially useful for MTX removal in cases where glucarpidase is not available. Additionally, fluid hydration, renal support and urine alkalinization are important adjunctive therapies for managing MTX toxicities.

A Case of Palmoplantar Keratoderma in the Constellation of Connective Tissue Diseases.

Overlap syndrome is a clinical challenge and brings together a wide range of treatment options for the treating physician. Addressing each and every complaint of the patient is crucial. A 50-year-old female patient presented with skin thickening, blackening, and hyperkeratosis; dysphagia; joint pain; features of myopathy; Raynaud's phenomenon; and dry mouth. Inflammatory markers were raised along with a positive antinuclear antibody (ANA) with Golgi apparatus pattern, anti-Sjögren's-syndrome-related antigen A (anti-SSA)/Ro60 3+, anti-SSA/Ro52 3+, and anti-PM/Scl 2+ antibodies that suggested overlap syndrome. Although the patient had no respiratory complaints, a unique interstitial lung disease (ILD) pattern was noted during the evaluation. Skin manifestations were puzzling, but the histopathology analyses of skin biopsies taken from two different sites revealed distinguishing features of cutaneous lupus and dermatomyositis. Treatment with hydroxychloroquine, pilocarpine, nifedipine, methotrexate, and topical tacrolimus produced a dramatic improvement in the clinical features. This case highlights subtle and florid features of different autoimmune diseases. The hyperkeratotic skin changes were the most striking feature, but the whole evaluation process unveiled many rare presentations of known autoimmune conditions that can open doors to new areas of our understanding toward connective tissue diseases (CTDs). Our case report demonstrates significant heterogeneity in the ANA patterns, ILD patterns, clinical manifestations, and treatment approaches.

Coronary Flow Reserve, Inflammation, and Myocardial Strain: The CIRT-CFR Trial.

Inflammation is a key determinant of cardiovascular outcomes, but its role in heart failure is uncertain. In patients with cardiometabolic disease enrolled in the prospective, multicenter ancillary study of CIRT (Cardiovascular Inflammation Reduction Trial), CIRT-CFR (Coronary Flow Reserve to Assess Cardiovascular Inflammation), impaired coronary flow reserve was independently associated with increased inflammation and myocardial strain despite well-controlled lipid, glycemic, and hemodynamic profiles. Inflammation modified the relationship between CFR and myocardial strain, disrupting the association between cardiac blood flow and function. Future studies are needed to investigate whether an early inflammation-mediated reduction in CFR capturing microvascular ischemia may lead to heart failure in patients with cardiometabolic disease. (Cardiovascular Inflammation Reduction Trial [CIRT]; NCT01594333; Coronary Flow Reserve to Assess Cardiovascular Inflammation [CIRT-CFR]; NCT02786134).

Predicting Hepatotoxicity Associated with Low-Dose Methotrexate Using Machine Learning.

An accurate prediction of the hepatotoxicity associated with low-dose methotrexate can provide evidence for a reasonable treatment choice. This study aimed to develop a machine learning-based prediction model to predict hepatotoxicity associated with low-dose methotrexate and explore the associated risk factors. Eligible patients with immune system disorders, who received low-dose methotrexate at West China Hospital between 1 January 2018, and 31 December 2019, were enrolled. A retrospective review of the included patients was conducted. Risk factors were selected from multiple patient characteristics, including demographics, admissions, and treatments. Eight algorithms, including eXtreme Gradient Boosting (XGBoost), AdaBoost, CatBoost, Gradient Boosting Decision Tree (GBDT), Light Gradient Boosting Machine (LightGBM), Tree-based Pipeline Optimization Tool (TPOT), Random Forest (RF), and Artificial Neural Network (ANN), were used to establish the prediction model. A total of 782 patients were included, and hepatotoxicity was detected in 35.68% (279/782) of the patients. The Random Forest model with the best predictive capacity was chosen to establish the prediction model (receiver operating characteristic curve 0.97, accuracy 64.33%, precision 50.00%, recall 32.14%, and F1 39.13%). Among the 15 risk factors, the highest score was a body mass index of 0.237, followed by age (0.198), the number of drugs (0.151), and the number of comorbidities (0.144). These factors demonstrated their importance in predicting hepatotoxicity associated with low-dose methotrexate. Using machine learning, this novel study established a predictive model for low-dose methotrexate-related hepatotoxicity. The model can improve medication safety in patients taking methotrexate in clinical practice.

Genetics are not likely to offer clinically useful predictions for elevated liver enzyme levels in patients using low dose methotrexate.

OBJECTIVE: To examine genetic influence on the risk of elevations in liver function tests (AST and ALT) among patients using low-dose methotrexate (LD-MTX). METHODS: We examined data from the LD-MTX arm of a randomized double-blind placebo-controlled trial conducted among subjects without rheumatic disease. Genome wide association studies (GWAS) were performed in subjects of European ancestry to test the association between single nucleotide polymorphisms (SNPs) and the log transformed maximum values of AST, ALT, and dichotomized outcome with AST or ALT > 2 times upper limit of normal (ULN). The association between variants in MTX metabolism candidate genes and the outcomes was also tested. Furthermore, associations between a drug induced liver injury (DILI) weighted genetic risk score (wGRS) and the outcomes were tested, combining 10 SNPs and 11 classical HLA alleles associated with DILI. RESULTS: In genome-wide genetic analyses among 1,429 subjects of European ancestry who were randomized to receive LD-MTX, two SNPs reached genome wide significance for association with log transformed maximum ALT. We observed associations between established candidate genes in MTX pharmacogenetics and log transformed maximum AST and ALT, as well as in dichotomized outcome with AST or ALT > 2 x ULN. There was no association between DILI wGRS or candidate variants and AST, ALT, or DILI response. CONCLUSIONS: Modest evidence was observed that common variants affected AST and ALT levels in subjects of European ancestry on LD-MTX, but this genetic effect is not useful as a clinical predictor of MTX toxicity.

Pancytopenia Due to Possible Drug-Drug Interactions Between Low-Dose Methotrexate and Proton Pump Inhibitors.

Methotrexate (MTX) has been widely used with a wide range of doses in the treatment of certain neoplastic diseases, severe psoriasis, and rheumatoid arthritis. At higher dose, monitoring of serum MTX elimination is performed because delayed elimination can result in serious and potentially life-threatening toxicities. A number of medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), salicylates, phenylbutazone, phenytoin, sulfonamides, and some oral antibiotics, are known to interact with MTX therapy through various mechanisms. Accumulating evidence suggests that concomitant use of MTX (primarily at high doses) and proton pump inhibitors (PPIs) such as omeprazole, esomeprazole, and pantoprazole may decrease MTX clearance. The majority of the reported cases occurred with the administration of high-dose MTX in patients receiving doses of 300 mg/m2 to 12 g/m2. However, there were also cases of patients taking PPI and experiencing toxicity at doses as low as 10 mg of MTX per week. Although the dosage of MTX is small, the presence of side effect may be delayed and still dangerous. After literature review, it was found that common toxicities associated with low-dose MTX used for inflammatory arthritis include gastrointestinal adverse effects (>10%; ie nausea, stomatitis) and central nervous system toxicity (~20%; ie fatigue, malaise, dizziness, impaired cognition) with weekly administration. Bone marrow suppression (<3%; ie leukopenia, neutropenia, thrombocytopenia) and hepatotoxicity (~15%; ie reversible elevations in transaminases) are less common, and rarely MTX can also cause pulmonary (<1%) and other toxicities. Here, we report two cases who presented with severe pancytopenia 8 and 13 days after taking low-dose MTX and PPI. We highlight that in absence of risk/benefit ratio correctly set, an assessment of appropriateness of PPI prescription before MTX therapy can limit an iatrogenic risk.

Disease activity and therapeutic drug monitoring of polyglutamates of methotrexate after daily or weekly administration of low-dose methotrexate in patients recently diagnosed with rheumatoid arthritis.

Low-dose methotrexate can be challenging to treat rheumatoid arthritis due to side effects, lack of adherence and risk of medication errors. The aim of this study was to explore the safety and efficacy of low-dose methotrexate administered daily or weekly in patients with rheumatoid arthritis. Patients were randomized according to a total oral dose of 12.5 mg of methotrexate administered: (A) divided in 5 days/week and (B) once per week. Patients were assessed along 24 weeks after starting treatment. Polyglutamates of methotrexate were quantified by ultrahigh-performance liquid chromatography coupled to tandem mass spectrometer. Patients from groups A and B showed a good response to methotrexate treatment in 29% and 25.5%, respectively, and a global frequency of adverse events of 37%. Methotrexate polyglutamate 3 concentrations were higher in normal weight (body mass index 18.5-24.9 kg/m2 ) than in obese (body mass index 30 kg/m2 ) patients with a median (interquartile range) of 28 (17.95-45.15) and 10.35 (5.22-30.88) nM without differences between dosage groups. Daily dosage regimen represents a therapeutic alternative without compromising the efficacy and safety of methotrexate treatment and with similar adherence patterns than weekly dosage regimen; further, methotrexate polyglutamate 3 concentrations could be a useful tool for therapeutic drug monitoring purposes.

Low-Dose Methotrexate Toxicity Presenting as Pancytopenia.

High-dose methotrexate (MTX, 5 g/week) is typically used for the treatment of different malignancies and may be associated with serious side effects, such as acute kidney injury, myelosuppression, and hepatotoxicity. On the other hand, low-dose MTX (10-25 mg/week) is considered to be a safe and effective treatment for autoimmune arthropathies. Toxicity due to low-dose MTX is rare but can present with serious complications, such as pancytopenia. In this report, we present the case of an 82-year-old woman who presented with low-dose, MTX-induced severe pancytopenia and was treated with leucovorin rescue therapy with granulocyte colony-stimulating factor (G-CSF) therapy.

Potential contributors to low dose methotrexate toxicity in a patient with rheumatoid arthritis and pernicious anemia: case report.

BACKGROUND: Low dose methotrexate toxicity rarely occurs, but may present with severe complications, such as pancytopenia, hepatotoxicity, mucositis, and pneumonitis. Known risk factors for methotrexate toxicity include dosing errors, metabolic syndrome, hypoalbuminemia, renal dysfunction, lack of folate supplementation, and the concomitant use of drugs that interfere with methotrexate metabolism. Vitamin B12 deficiency leads to megaloblastic anemia and may cause pancytopenia, but its role in methotrexate toxicity has not been described. CASE PRESENTATION: We present a case of a patient with rheumatoid arthritis who was admitted with febrile neutropenia, pancytopenia, and severe mucositis, likely secondary to low dose methotrexate toxicity. She had multiple factors that potentially contributed to the development of toxicity, including concurrent sulfasalazine use for rheumatoid arthritis. An evaluation of the patient's macrocytic anemia revealed pernicious anemia. The patient's illness resolved with cessation of methotrexate and sulfasalazine, leucovorin treatment and vitamin B12 repletion. CONCLUSIONS: This case illustrates the multiple factors that may potentially contribute to low dose methotrexate toxicity and highlights the importance of testing for vitamin B12 deficiency in rheumatoid arthritis patients with macrocytic anemia. Addressing all the modifiable factors that potentially contribute to low dose methotrexate toxicity may improve outcomes.

Methotrexate Triglutamate as a Determinant of Clinical Response in Mexican Patients With Rheumatoid Arthritis: Pharmacokinetics and Dose Recommendation.

Methotrexate is the gold standard treatment in rheumatoid arthritis. Once absorbed, it is internalized in cells, where glutamate residues are added to produce polyglutamated forms, which are responsible for the effect of methotrexate. The aim of the current study is to determine the relationship between methotrexate triglutamate concentrations and the clinical evolution in rheumatoid arthritis patients, as well as to characterize the variability in both features to propose strategies for low-dose methotrexate optimization. The quantification of methotrexate triglutamate concentration in red blood cells was performed through ultra-performance liquid chromatography coupled with mass spectrometry. Polymorphisms of genes involved in the formation of polyglutamates were determined by real-time polymerase chain reaction. A multivariate regression was performed to determine the covariates involved in the variability of methotrexate triglutamate concentrations and a population pharmacokinetics model was developed through nonlinear mixed-effects modeling. Disease activity score changed according to methotrexate triglutamate concentrations; patients with good response to treatment had higher concentrations than moderate or nonresponding patients. The methotrexate triglutamate concentrations were related to time under treatment, dose, red blood cells, and body mass index. A 1-compartment open model was selected to estimate the pharmacokinetic parameters; the typical total clearance (L/day) was determined as 1.45 * (body mass index/28 kg/m2 ) * (red blood cells/4.6 × 106 cells/µL) and the volume of distribution was 52.4 L, with an absorption rate of 0.0346/day and a fraction metabolized of 1.03%. Through the application of the model, the initial dose of methotrexate is proposed on the basis of stochastic simulations and considering methotrexate triglutamate concentrations found in responders patients.

Low-dose Methotrexate Treatment for Solitary or Localized Primary Cutaneous Anaplastic Large Cell Lymphoma: A Long-term Follow-up Study.

Although low-dose methotrexate (MTX) has been used widely in treatment of a variety of dermatological diseases, including multifocal primary cutaneous anaplastic large cell lymphoma (PCALCL), it has not been established for use in the treatment guidelines for solitary or localized PCALCL. Furthermore, there has been no report of long-term follow-up data in Asian patients with PCALCL treated with low-dose MTX. To investigate the effectiveness and clinical outcome of treatment with low-dose MTX, clinical and long-term follow-up data of 7 patients with solitary or localized PCALCL were analysed retrospectively. Of the 7 patients, 6 (85.7%) showed a complete response and 1 (14.3%) showed partial remission. During follow-up, mean duration of 92.1 months, 5 patients developed one or more cutaneous relapses. At the last follow-up, all of the patients with PCALCL were alive without disease. These results indicate that low-dose MTX is a highly effective and safe treatment for solitary or localized PCALCL as well as multiple relapsed lesions.

Methotrexate Cutaneous Toxicity following a Single Dose of 10 mg in a Case of Chronic Plaque Psoriasis: A Possible Idiosyncratic Reaction.

Low-dose methotrexate is a well-tolerated and inexpensive systemic immunosuppressive agent used commonly in dermatology. However, several adverse events such as pancytopenia, pneumonitis, mucositis, and cutaneous ulcerations may develop during acute toxicity with dose-dependent or idiosyncratic mechanisms. Risk factors for methotrexate toxicity include advanced age, hypoalbuminemia, renal dysfunction, and concomitant drugs increasing the level of methotrexate in the body. We present a case of methotrexate toxicity presenting with classical features along with mucocutaneous side-effects, such as ulceration of psoriatic plaques and acral erythema, following a single dose of methotrexate.

How should we manage low-dose methotrexate-induced pancytopenia in patients with rheumatoid arthritis?

Low-dose methotrexate (ld-MTX) that is administered during rheumatoid arthritis (RA) treatment has hematological adverse effects such as pancytopenia, although rare. Although well-established and widely used for hematological adverse effects caused by high-dose MTX, leucovorin (folinic acid) treatment does not have an agreed-upon administration for ld-MTX-induced pancytopenia. Here, we aimed to figure out whether there was any difference in response time between the regimens with and without folinic acid prescribed to our patients who developed pancytopenia while on MTX therapy, and to identify risk factors for its development. Our cases were collectively assessed together with other rare cases available in the literature that were reported in a similar manner with an explicitly indicated response time, in days. Thereupon, we looked for any difference in response time between the regimens with and without folinic acid. In total, ten of our patients experienced pancytopenia while on ld-MTX treatment. Mean day on which hematological response was achieved was as follows: 7 days in one patient on folic acid monotherapy, 6 days in three patients on granulocyte-colony stimulating factor (G-CSF) monotherapy, 4.5 days in two patients on leucovorin monotherapy, and 4 days in the remaining three patients who were treated with G-CSF + folinic acid/leucovorin. When we collectively evaluated our patients and the patients with an explicitly stated response duration in the literature (15 patients) and compared regimens including folinic acid to those without folinic acid, duration until response/recovery from pancytopenia was significantly shorter in folinic acid group than that in the group without folinic acid (5.47 ± 2.9 days vs 10 ± 3.77 days, p = 0.002). Treatment modalities including folinic acid (leucovorin) either with or without G-CSF result in a shorter recovery/response time compared to other agents. Leucovorin should definitely be considered and applied in rescue therapy for ld-MTX-associated side effects.

Can etanercept treatment failure in moderate-to-severe psoriasis be overcome by addition of low-dose methotrexate? A single-center experience.

BACKGROUND: Loss of efficacy is a major anticipated shortcoming of utilizing etanercept and other biologic agents for treating moderate-to-severe psoriasis. PURPOSE: To investigate the addition of low-dose methotrexate as a means to increase etanercept drug survival. METHODS: Eleven patients with severe psoriasis were switched to a combination of etanercept with low-dose methotrexate therapy, after a primary or secondary failure with etanercept treatment as a monotherapy. Time period for cessation of combined treatment and side effects were documented. The effect of previous methotrexate treatment was investigated. RESULTS: Six men and five women were included in the study. The patients had moderate-to-severe psoriasis with a mean baseline Psoriasis Area and Severity Index (PASI) of 29 (median 25). Median duration of etanercept monotherapy was 12 months. Median duration of combined treatment was 13 months. Combined treatment was discontinued in three patients due to side effects. Previous failure of methotrexate monotherapy did not alter the duration of the combined treatment. CONCLUSION: Addition of low-dose methotrexate may rescue etanercept therapy after failure of etanercept monotherapy in patients with moderate-to-severe psoriasis.

Landmark papers on the discovery of methotrexate for the treatment of rheumatoid arthritis and other systemic inflammatory rheumatic diseases: a fascinating story.

This review highlights the story of how methotrexate (MTX), a drug discovered for the treatment of childhood leukemia, became the mainstay of treatment and the standard-of-care for rheumatoid arthritis (RA) and was also found useful for several additional related rheumatological diseases. As against several synthetic disease-modifying antirheumatic drugs (csDMARDs) for treating RA that were discovered serendipitously, the use of low-dose MTX (LD-MTX) was based on sound reasoning and astute observations made in the 1940s and 1950s. The difference between high-dose MTX (HD-MTX) used in the treatment of childhood leukaemia and other malignancies as against LD-MTX used in rheumatology is emphasized.

Treatment of rheumatoid arthritis (RA) in India-how and by whom: results from a speciality clinic-use of low-dose methotrexate (MTX) was inexplicably suboptimal.

This study was conducted in order to study (a) seropositive RA patients for their prior caregivers, diagnosis makers, drugs and doses taken and (b) the disease status at the first visit and the last visit, from the standpoint of whether they received optimum or suboptimum DMARD treatment. Prospectively entered data were extracted from a rheumatology-specific electronic health record for demography, diagnostic delay, prior caregivers, diagnosis makers, intake of DMARDs and glucocorticoids and disease activity state at first presentation and at the last visit using structured query language. Among 316 patients, prior caregivers were orthopaedicians (73.4 %), alternative systems of medicine practitioners (62 %), internists (38 %), rheumatologists (35.8 %), general practitioners (17 %) and others (12 %). The diagnosis of RA was made by rheumatologists (55.6 %), orthopaedicians (21 %), internists (12.6 %), physiotherapists (3.5 %), homeopaths (2.8 %), general practitioner (2.1 %), neurologists (1.4 %) and Ayurvedic physicians (0.7 %). The mean and the median diagnostic delay among 142 patients where information was available were 18 and 8.5 months, respectively (SD +23.2). Thirty-two percent of the patients had early disease, 48 % established disease and 20 % late disease at presentation. Sixty-six percent of the patients had taken DMARDs-methotrexate (56 %), hydroxychloroquine (46.2 %), leflunomide (18.7 %) and sulfasalazine (20.6 %)-and often in combinations. Different preparations, doses and schedules of glucocorticoids were taken orally or parentally by 51 %. Only one (0.3 %) patient had taken biological DMARDs prior to visiting this clinic. High or moderate disease activity was present in 84 % at the first clinic visit that fell to 14 % at the last clinic visit. The majority of patients with RA were treated by orthopaedicians and practitioners of alternative systems of medicine with only a third by rheumatologists. In 80 % of patients, the diagnosis was made 18 months at the onset, yet in 84 %, the disease control was poor. Non-use or suboptimal use of methotrexate appeared to be the main reason.

No evidence for an increased risk of adverse pregnancy outcome after paternal low-dose methotrexate: an observational cohort study.

OBJECTIVE: There is increasing awareness of the potential impact of paternal exposures on pregnancy outcome. In particular this applies to MTX, which is used in low doses for the treatment of RA and other inflammatory diseases. MTX is associated with a specific pattern of malformations in fetuses of exposed women, but there is uncertainty concerning the risk of paternal low-dose MTX. The aim of this study was to investigate whether paternal low-dose MTX therapy around conception has an unfavourable effect on pregnancy outcome. METHODS: We performed a prospective observational cohort study involving pregnancies fathered by men who were treated with low-dose MTX around conception. Pregnancies were identified through our Teratology Information Service. Pregnancy outcomes were compared with a cohort neither exposed to MTX nor to other teratogens. Outcomes evaluated were major birth defects, spontaneous abortion (SAB), elective termination of pregnancy, gestational age at delivery, and birth weight. RESULTS: A total of 113 pregnancies with paternal low-dose MTX treatment were compared with 412 non-exposed pregnancies. Neither the rate of major birth defects [odds ratio (OR) 1.02, 95% CI 0.05, 7.0) nor the risk of SAB (hazard ratio 1.19, 95% CI 0.65, 2.17) was increased. Gestational age at delivery and birth weights did not differ significantly between groups. The rate of electively terminated pregnancies was increased in the MTX-exposed patients compared with controls. CONCLUSION: Our study does not confirm an increased risk of adverse pregnancy outcome after paternal low-dose MTX therapy. The reassuring findings do not support the necessity of a 3-month MTX-free interval until conception. In the case of unavoidable paternal MTX therapy, it seems reasonable not to postpone family planning.

Scleredema diabeticorum partially treated with low-dose methotrexate: a report of five cases.

Scleredema is a rare connective tissue disorder that belongs to a group of scleroderma-like disorders. Although no known curative therapy exists, various specific treatments have been proposed in the literature. In this report, we describe five cases of scleredema partially treated with low-dose methotrexate therapy. All patients have diabetes mellitus type II. All patients were started on methotrexate 15 mg subcutaneously once weekly for 3 months. Biopsy specimens were taken from all patients and were examinated histologically before the treatment and after 3 months of treatment. All cases partially responded to low-dose methotrexate therapy. We believe that methotrexate therapy may be an alternative therapeutic options in scleredema in view of its efficacy.