Methotrexate: new therapeutic approaches

Methotrexate for Drug Repurposing as an Anti-Aggregatory Agent to Mercuric Treated α-Chymotrypsinogen-A

Protein aggregation is related to numerous pathological conditions like Alzheimer's and Parkinson's disease. In our study, we have shown that an already existing FDA-approved drug; methotrexate (MTX) can be reprofiled on preformed α-chymotrypsinogen A (α-Cgn A) aggregates. The zymogen showed formation of aggregates upon interaction with mercuric ions, with increasing concentration of Hg2Cl2 (0-150 µM). The hike in ThT and ANS fluorescence concomitant with blue shift, bathochromic shift and the hyperchromic effect in the CR absorbance, RLS and turbidity measurements, substantiate the zymogen β-rich aggregate formation. The secondary structural alterations of α- Cgn A as analyzed by CD measurements, FTIR and Raman spectra showed the transformation of native β-barrel conformation to β-inter-molecular rich aggregates. The native α- Cgn A have about 30% α-helical content which was found to be about 3% in presence of mercuric ions suggesting the formation of aggregates. The amorphous aggregates were visualized by SEM. On incubation of Hg2Cl2 treated α- Cgn A with increasing concentration of the MTX resulted in reversing aggregates to the native-like structure. These results were supported by remarkable decrease in ThT and ANS fluorescence intensities and CR absorbance and also consistent with CD, FTIR, and Raman spectroscopy data. MTX was found to increase the α-helical content of the zymogen from 3 to 15% proposing that drug is efficient in disrupting the β-inter-molecular rich aggregates and reverting it to native like structure. The SEM images are in accordance with CD data showing the disintegration of aggregates. The most effective concentration of the drug was found to be 120 µM. Molecular docking analysis showed that MTX molecule was surrounded by the hydrophobic residues including Phe39, His40, Arg145, Tyr146, Thr151, Gly193, Ser195, and Gly216 and conventional hydrogen bonds, including Gln73 (bond length: 2.67Å), Gly142 (2.59Å), Thr144 (2.81Å), Asn150 (2.73Å), Asp153 (2.71Å), and Cys191 (2.53Å). This investigation will help to find the use of already existing drugs to cure protein misfolding-related abnormalities.

Risk factors associated with high-dose methotrexate induced toxicities

INTRODUCTION

High-dose methotrexate (HDMTX) therapy poses challenges in various neoplasms due to individualized pharmacokinetics and associated adverse effects. Our purpose is to identify early risk factors associated with HDMTX-induced toxicities, paving the way for personalized treatment.

AREAS COVERED

A systematic review of PubMed and Cochrane databases was conducted for articles from inception to July 2023. Eligible studies included reviews, clinical trials, and real-world analyses. Irrelevant studies were excluded, and manual searches and citation reviews were performed. Factors such as MTX exposure, drug interactions, demographics, serum albumin, urine pH, serum calcium, and genetic polymorphisms affecting MTX transport (e.g. SLCO1B1), intracellular folate metabolism (MTHFR), cell development (ARID5B), metabolic pathways (UGT1A1, PNPLA3), as well as epigenetics were identified.

EXPERT OPINION

This comprehensive review aids researchers and clinicians in early identification of HDMTX toxicity risk factors. By understanding the multifaceted risk factors associated with hematologic malignancies, personalized treatment approaches can be tailored to optimize therapeutic outcomes.

Whey protein concentrate ameliorates the methotrexate-induced liver and kidney damage

Methotrexate (MTX) is a cytotoxic immunosuppressant that is widely used in the treatment of tumours, rheumatoid arthritis and psoriasis. This study aims to evaluate the effects of whey proteins on MTX-induced liver and kidney damage by focusing on oxidant–antioxidant systems and eating habits. The study was conducted in four groups of thirty Sprague–Dawley rats (control, control + whey protein concentrate (WPC), MTX, MTX + WPC). A single dose of 20 mg/kg MTX was administered intraperitoneally to the MTX groups. Control and MTX groups were given 2 g/kg WPC by oral gavage every day for 10 d. At the end of day 10, blood samples were drawn and liver and kidney tissues were removed. MTX administration increased the lipid peroxidation level and decreased glutathione level, superoxide dismutase and glutathione-S-transferase activities in the liver and kidney. Administration of WPC significantly reduced the damage caused by MTX in the liver and kidney. While a decrease in serum urea level and an increase in serum creatinine level were detected in the MTX group, WPC administration reversed these results up to control group levels. Administration of WPC to the MTX group significantly reversed the histopathological damage scores of the liver and kidney. WPC administration ameliorated the MTX-induced oxidative damage in the liver and kidney tissues due to its antioxidant properties. Liver and kidney damage can be prevented by using whey proteins as a nutraceutical in MTX therapy. In conclusion, whey proteins demonstrated a protective effect against MTX-induced liver and kidney damage.

Buspirone attenuated methotrexate-induced hippocampal toxicity in rats by regulating Nrf2/HO-1, PPAR-γ, NF-κB/nNOS, and ROS/NLRP3/caspase-1 signaling pathways

Methotrexate (MTX) is a chemotherapeutic agent widely used to treat a variety of tumors. Nonetheless, MTX-induced hippocampal neurotoxicity is a well-defined dose-limiting adverse effect that limits clinical utility. Proinflammatory cytokine production and oxidative stress are possible mechanisms for MTX-induced neurotoxicity. Buspirone (BSP), a partial agonist of the 5-HT1a receptor (5-HT1aR), has emerged as an anxiolytic drug. BSP has been shown to possess antioxidant and anti-inflammatory effects. The current study investigated BSP's potential anti-inflammatory and antioxidant effects in attenuating MTX-induced hippocampal toxicity. Rats received either BSP (1.5 mg/kg) orally for 10 days and MTX (20 mg/kg) i.p. on Day 5. BSP administration markedly protected hippocampal neurons from drastic degenerated neuronal changes induced by MTX. BSP significantly attenuated oxidative injury by downregulating Kelch-like ECH-associated protein 1 expression while potently elevating hippocampal Nrf2, heme oxygenase-1, and peroxisome proliferator-activated receptor expression. BSP dampened inflammation by reducing NO2 - , tumor necrosis factor-alpha, IL-6, and interleukin 1 beta levels mediated by downregulating NF-κB and neuronal nitric oxides synthase expression. Moreover, BSP potently counteracted hippocampal pyroptosis by downregulating NLRP3, ASC, and cleaved-caspase-1 proteins. Therefore, BSP may represent a promising approach to attenuate neurotoxicity in patients receiving MTX.

Manjari Medika Grape Seed Extract Protects Methotrexate-Induced Hepatic Inflammation: Involvement of NF-κB/NLRP3 and Nrf2/HO-1 Signaling System

Objective

Grape Seed Extract is a natural source of various polyphenols, which have been shown to possess potent antioxidant and free radical-scavenging activities. The earlier studies have reported that grape seed extract exhibits broad-spectrum pharmacological activities. Therefore, studying the hepatoprotective effects and elucidation of mechanisms of action of the Indian Variety, Manjari Medika grape seed extract (GSE), may give an insight into therapeutic benefits. Methotrexate (MTX) is the first-line pharmacological therapy for different rheumatic diseases. The major adverse events such as hepatotoxicity are evident even in the low doses used for the treatment. The present study investigated the role of MTX on hepatic damage in murine liver and the plausible protective effects of the Indian grape variety, Manjari Medika grape seed extract, in ameliorating it.

Methods and Results

To assess the hepatological modulation, mice were divided into eight groups to investigate the ameliorative potential of this GSE (75 and 125 mg/kg) and correlate the experimental findings. The active components of the extract were assessed through UPLC-(ESI)-QToF-MS analysis. On the other hand, various biochemical and immunological indices were carried out to correlate the experimental data. The result demonstrated that the prophylactic administration of GSE reduced MTX-induced hepatic toxicity indices, which subsequently restored the hepatic morphological architecture. Moreover, the application of GSE in a dual dosage (75 and 125 mg/kg) suppressed MTX-induced reactive oxygen species generation, followed by lipid peroxidation and cellular nitrite formation. MTX-induced inflammasome activation through the redox-assisted cascade of TLR4/NF-κB signaling was further reduced by applying the GSE. The results showed that the activation of cytoprotective transcription factor Nrf2 enhanced the level of endogenous antioxidants. Furthermore, through the regulation of TLR4/NF-κB and Nrf2/HO-1 axis, this extract could reduce the MTX-mediated hepatic damage.

Conclusion

Our findings suggest that Manjari Medika seed extract could be used as a therapeutic agent to relieve the side effects of MTX and other hepatic disorders.

HLA-C Genotyping Reveals Haplotype C*07 as a Potential Biomarker of Late Psoriasis Onset in Moroccan Patients

Psoriasis still has an unknown etiology. Genetic predisposition shows the association between HLA-Cw6 allele and psoriasis. Although biotherapies have been proven effective in psoriasis treatment, methotrexate (MTX) is still used as a first-line systemic therapy due to its efficacy/affordability, but the differential response to MTX is mostly related to interindividual genetic variability and remains an issue. Our study aimed to analyze HLA-C allele frequencies in a sample of Moroccan psoriatic patients and assess the therapeutic response to MTX. Whole blood of 54 Moroccan psoriatic patients was collected and DNA was extracted. Patients' HLA-C locus was genotyped by PCR-SSO. Results were analyzed with Luminex xMAP Technology and Match-it DNA Evolution 3.4. HLA-C typing results of 77 sex- and age-matched unrelated non-psoriatic healthy subjects were included. We observed no difference in the allelic distribution of HLA-C between patients and healthy controls, suggesting that none of the HLA-C alleles were significantly associated with psoriasis. Moreover, the HLA-C*07 allele was associated with a late age at disease onset (>30 years old) (p = 0.007). No statistically significant association was found between HLA-C allele expression and response to MTX, despite a higher frequency of HLA-C*06 in responders compared to non-responders. Thus, HLA-C*07 could be a biomarker of late psoriasis onset in the Moroccan population.

Punicalagin Protects against the Development of Methotrexate-Induced Hepatotoxicity in Mice via Activating Nrf2 Signaling and Decreasing Oxidative Stress, Inflammation, and Cell Death

Despite its effectiveness in treating inflammatory diseases and various malignancies, methotrexate (MTX) is well known to cause hepatotoxicity, which involves increased oxidative stress and inflammation, limiting its clinical use. Herein, we looked into the effect of punicalagin (PU), a polyphenolic molecule having a variety of health-promoting attributes, on MTX-induced hepatotoxicity in mice. PU (25 and 50 mg/kg/day) was given orally to the mice for 10 days, while a single dose of MTX (20 mg/kg) was injected intraperitoneally (i.p.) at day 7. The MTX-induced liver damage was demonstrated by remarkably higher transaminases (ALT and AST), ALP, and LDH, as well as significant histological alterations in hepatic tissues. MTX-injected mice also demonstrated increases in hepatic oxidative stress markers, including malondialdehyde (MDA) and nitric oxide (NO), with a concordant drop in glutathione (GSH) content and superoxide dismutase (SOD) and catalase (CAT) activities. PU significantly attenuated the MTX-induced serum transaminases, ALP and LDH elevations, and hepatic oxidative stress measures and boosted antioxidant defenses in the liver. Moreover, the liver of MTX-treated mice showed increases in NF-κB p65 expression, pro-inflammatory cytokine (IL-6 and TNF-α) levels, and pro-apoptotic protein (caspase-3 and Bax) expression, whereas Bcl-2 and Nrf2 expressions were reduced, which were all attenuated by PU treatment. Collectively, PU inhibits oxidative damage, inflammation, and apoptosis and upregulates Nrf2 in the liver of MTX-induced mice. Thus, these findings suggest that PU may have great therapeutic potential for the prevention of MTX-induced hepatotoxicity, pending further exploration in upcoming studies.

Combination of Methotrexate and Leflunomide Is Efficient and Safe for 60 Patients with Rheumatoid Arthritis

The present work is aimed at exploring the clinical efficacy and safety of methotrexate (MTX) and leflunomide (LEF) combination therapy for rheumatoid arthritis. From June 2019 to June 2021, a total of 120 individuals with rheumatoid arthritis received a diagnosis. Sixty patients each were randomly assigned to the control and observation groups. The observation group received MTX and LEF combo medication while the control group only received MTX treatment. Clinical efficacy, complication incidence, and the alleviation of inflammatory markers, joint pain, and clinical symptoms were compared between the 2 groups. Posttreatment, the observation group had overall response rate of 96.66%, while the control group had 86.67%, with significant differences. Compared with pretreatment, both control and observation group patients showed decreasing trends of IL-1 levels and increasing trends of IL-10 levels posttreatment, with significant differences ( $P<0.05$ ). Compared with the control group, patients in the observation group had lower IL-1 and TNF-α levels with significant differences ( $P<0.05$ ) and higher levels of IL-10 with significant difference ( $P<0.05$ ). In both groups, the pain score and the number of painful joints were much lower than they were prior to treatment. Following treatment, the observation group displayed significantly lower levels of erythrocyte sedimentation rate, rheumatoid factor, and C-reactive protein than the control group ( $P<0.05$ ). Clinical measures in the observation group were all lower than those in the control group with statistically significant differences ( $P<0.05$ ). Moreover, the incidence rate of adverse reactions showed no significant difference between these 2 groups ( $P>0.05$ ). In conclusion, the combination therapy of MTX and LEF is efficacious for rheumatic arthritis.

Towards Personalized Medicine in Psoriasis: Current Progress

Although innovative targeted therapies have positively revolutionized psoriasis treatment shifting treatment goals to complete or almost complete skin clearance, primary or secondary lack of efficacy is still possible. Hence, identifying robust biomarkers that reflect the various clinical psoriasis phenotypes would allow stratify patients in subgroups or endotypes, and tailor treatments according to the characteristics of each individual (precision medicine). To sum up the current progress in personalized medicine for psoriasis, we performed a review on the available evidence on biomarkers predictive of response to psoriasis treatments, with focus on phototherapy and systemic agents. Relevant literature published in English was searched for using the following databases from the last five years up to March 20, 2022: PubMed, Embase, Google Scholar, EBSCO, MEDLINE, and the Cochrane library. Currently, more evidence exists towards biologicals, as justified by the huge health care costs as compared to phototherapy or conventional systemic drugs. Among them, most of the studies focused on anti-TNF and IL12/23, with still few on IL17 (mainly secukinumab). The most discussed biomarker gene is the HLA-C*02:06 status that has been shown to be associated with psoriasis, and also differential response to biologicals. Although its positivity is associated with great response to MTX, debatable results were retrieved concerning both anti-TNF and IL12/23 while it seems not to affect secukinumab response. Personalized treatment in psoriasis would provide excellent outcome minimizing the risk of side effects. To date, although several candidates were proposed and assessed, the scarcity and heterogeneity of the results do not allow the identification of the gold-standard biomarker per each treatment. Anyway, the creation of a more comprehensive panel would be more reliable for the treatment decision process.

Febrile neutropenia following with single-low-dose methotrexate for the treatment of ectopic pregnancy: a case report

Methotrexate (MTX) is an effective, economical and safe drug used in the treatment of ectopic pregnancy. Complications are very rare. Herein, we reported a case of febrile neutropenia following single low-dose methotrexate for the treatment of ectopic pregnancy. Febrile neutropenia developed on day 4 of single-dose methotrexate administered intramuscularly. Although methotrexate single-dose regimen is quite effective and safe in ectopic pregnancy, febrile neutropenia can occur very rarely.

Predictive factors of treatment success in two-dose methotrexate regimen in ectopic tubal pregnancy: A retrospective study

Objectives

To investigate the predictive factors of success or failure in treating ectopic tubal pregnancies with two-dose methotrexate (MTX).

Methods

The records of patients treated for tubal EP with two-dose MTX were retrospectively reviewed. Patients were divided into two groups; the Group-I (failure) consisted of patients who did not respond to MTX therapy and the Group-II (success) included patients who were successfully treated with MTX. Parameters, including the week of gestation, presence or absence of fetal cardiac activity, gestational sac size, serum β-hCG levels, and adverse effects were compared.

Results

Fifty patients were included in this study, 8 (16%) were in Group-I and 42 (84%) were in Group-II. Patients in Group-I required surgery after a mean duration of 6.7±3 days after administering the initial dose of MTX. There was no difference between the groups in terms of the week of gestation, presence or absence of fetal cardiac activity, gestational sac size, serum β-hCG levels, and adverse effects. The average time to β-hCG negativization was 31 days in Group-II.

Conclusions

The two-dose MTX protocol has a reasonable success rate, which seems to be dependent on serum β-hCG levels.

One-Carbon Metabolism Associated Vulnerabilities in Glioblastoma: A Review

Simple Summary

Glioblastoma tumours are the most malignant and common type of central nervous system tumours. Despite aggressive treatment measures, disease recurrence in patients with glioblastoma is inevitable and survival rates remain low. Glioblastoma cells, like other cancer cells, can leverage metabolic pathways to increase their rate of proliferation, maintain self-renewal, and develop treatment resistance. Furthermore, many of the metabolic strategies employed by cancer cells are similar to those employed by stem cells in order to maintain self-renewal and proliferation. One-carbon metabolism and de novo purine synthesis are metabolic pathways that are essential for biosynthesis of macromolecules and have been found to be essential for tumourigenesis. In this review, we summarize the evidence showing the significance of 1-C-mediated de novo purine synthesis in glioblastoma cell proliferation and tumourigenesis, as well as evidence suggesting the effectiveness of targeting this metabolic pathway as a therapeutic modality.

Abstract

Altered cell metabolism is a hallmark of cancer cell biology, and the adaptive metabolic strategies of cancer cells have been of recent interest to many groups. Metabolic reprogramming has been identified as a critical step in glial cell transformation, and the use of antimetabolites against glioblastoma has been investigated. One-carbon (1-C) metabolism and its associated biosynthetic pathways, particularly purine nucleotide synthesis, are critical for rapid proliferation and are altered in many cancers. Purine metabolism has also been identified as essential for glioma tumourigenesis. Additionally, alterations of 1-C-mediated purine synthesis have been identified as commonly present in brain tumour initiating cells (BTICs) and could serve as a phenotypic marker of cells responsible for tumour recurrence. Further research is required to elucidate mechanisms through which metabolic vulnerabilities may arise in BTICs and potential ways to therapeutically target these metabolic processes. This review aims to summarize the role of 1-C metabolism-associated vulnerabilities in glioblastoma tumourigenesis and progression and investigate the therapeutic potential of targeting this pathway in conjunction with other treatment strategies.

Effects of vitamin B12 on methotrexate hepatotoxicity: evaluation of receptor-interacting protein (RIP) kinase

In the study, we aimed to show the effects of vitamin B12 on the necrosis caused by methotrexate (MTX), a folic acid antagonist. Thirty-two rats were randomly assigned to four groups of eight rats per group. Control (n = 8), Vit B12 (n = 8) 3 μg/kg/ip B12 (15 days) per day throughout the experiment, MTX (n = 8) injected with a single dose of 20 mg/kg/ip MTX on 8th day of experiment, MTX + Vit B12 (n = 8) injected with a single dose of 20 mg/kg ip methotrexate on 8th day of experiment + 3 μg/kg/ip Vit B12 (15 days) per day throughout the experiment. Oxidant (TOS)/antioxidant (TAS) system, TNF-α and TGF-β levels, AST and ALT, serum vitamin B12 levels were determined in the tissue. Cyclooxygenase-2 (Cox-2), receptor-interacting protein kinase 1 (RIP1) and 3 (RIP3) immunohistochemistry were applied to the liver tissue. TOS increased; TAS decreased; TNF-α and TGF-β levels increased; AST and ALT levels changed after MTX hepatotoxicity. Vit B12 decreased significantly. COX-2, RIP1, and RIP3 immunoreactivity increased. Vit B12 showed improvement in all of the negative results. Vit B12 is an important supplement to be used against necrosis in tissue after MTX hepatotoxicity.

A Review of Clinical Applications and Side Effects of Methotrexate in Ophthalmology

Methotrexate (MTX) is a folate analog widely used against a range of diseases including malignancies and autoimmune disorders. Its high effectiveness-price ratio also won extensive application in ophthalmology. On the other hand, although MTX has an excellent pharmacological efficacy, MTX associated side effects in clinical use, which vary from patient to patient, are nonnegligible. There is no comparatively systematic review on MTX associated side effects and its risk factors. This review aimed to reveal novel clinical approaches of MTX and its adverse effects in order to provide a reference for ophthalmic scholars in clinical application of MTX.

Update on subcutaneous methotrexate for inflammatory arthritis and psoriasis

Methotrexate (MTX) is one of the mainstays of treatment for several immune-mediated inflammatory joint and skin diseases, especially rheumatoid arthritis (RA) and moderate-to-severe psoriasis. Oral MTX has been used for the treatment of such diseases for decades for many reasons. There is, however, a relevant interpatient variability of clinical and safety outcomes that can also be related to differences in patients’ individual pharmacogenomic profile. Orally administered MTX has been found to have a saturable intestinal absorption and nonlinear pharmacokinetics, with significant consequences on drug bioavailability and clinical efficacy. The current evidence shows that parenterally administered MTX results in rapid and complete absorption, higher serum levels, and less variable exposure than oral dosing. The use of parenteral MTX, particularly when administered as a subcutaneous (SC) injection, has recently raised great interest in order to overcome the limitations of oral MTX. The effectiveness and safety of SC MTX have mostly been assessed in rheumatological settings, especially in patients with RA. There are only a limited number of data on SC MTX in juvenile idiopathic arthritis and even fewer in psoriatic disease. Various clinical experiences have suggested that SC MTX is more effective than oral MTX and may provide significant benefit even in patients in whom oral MTX proved to be inadequate. The increased efficacy of SC MTX resulting from higher drug exposure compared with oral MTX has been associated with a similar safety profile and in various reports even with a lower frequency of gastrointestinal complaints. The aim of this article was to review the available literature data on SC MTX treatment of inflammatory arthritis, with special emphasis on RA and psoriasis, examining differences with oral MTX treatment. A brief mention of pharmacokinetics, pharmacodynamic features and pharmacoeconomic considerations is also given.

Practical Management of Immunosuppressants in Dermatology

The treatment of inflammatory and autoimmune diseases is challenging because of their frequency and complexity. Treatment of these diseases is based on the suppression of the patient's immune system using corticosteroids, corticosteroid-sparing immunosuppressive agents, and biologic drugs, making an understanding of the management of immunosuppressive therapy essential. Before an immunosuppressive agent is prescribed, a study must be carried out to identify contraindications, detect latent infections, and determine the most appropriate dose. During treatment, regular monitoring is required to detect adverse effects. The clinician must be familiar with the time lag between start of treatment and onset of the immunosuppressive effect as well as the maximum recommended duration of treatment and cumulative dose for each drug. As dermatologists we are accustomed to using these immunosuppressive agents, but we should have a good knowledge of the guidelines for their use and the monitoring required in each case if we are to reduce variability and avoid potentially serious adverse effects.

Subcutaneous methotrexate for symptomatic control of severe recalcitrant psoriasis: safety, efficacy, and patient acceptability

Background

Although oral methotrexate is an effective first-line traditional systemic therapy for psoriasis, the use of the subcutaneous form of methotrexate for the treatment of psoriasis has not been fully established.

Objective

This study is a literature review of the research related to the safety, efficacy, and patient acceptability of subcutaneous methotrexate for its application in the treatment of severe recalcitrant psoriasis.

Methods

Systematic literature searches were conducted of the PubMed, Ovid, and ClinicalTrials.gov databases.

Results

Only three relevant sources of literature were found studying subcutaneous methotrexate specifically in the context of psoriasis. Of these, only one clinical trial was found to directly study the use of subcutaneous methotrexate in psoriasis patients; however, results of this study have not been published. The other two literature sources involved a cost-effectiveness analysis and a literature review for subcutaneous methotrexate. Otrexup™ and Rasuvo™ are two particular single-use auto-injector modalities of subcutaneous methotrexate that are approved by the US Food and Drug Administration. The equivalents of Rasuvo available in countries outside of the USA are advertised as Metoject^® or Metex^®. Much more research has been conducted on the use of subcutaneous methotrexate in rheumatoid arthritis patients.

Conclusion

There is a lack of original evidence-based studies evaluating the use of subcutaneous methotrexate specifically for the treatment of psoriasis. Based on the more extensively researched data on the safety, efficacy, and patient acceptability of subcutaneous methotrexate in rheumatoid arthritis patients, its application for the treatment of moderate-to-severe psoriasis is promising. More evidence-based studies on psoriasis subjects are needed to explore the practical application of subcutaneous methotrexate as a treatment option for severe recalcitrant psoriasis.

Systemic methotrexate for the treatment of psoriasis

In the era of biologic therapies, methotrexate (MTX), a classic immunomodulator, is still the cornerstone of systemic treatment of psoriasis. MTX has been used for many years, achieving good responses with a good safety profile. However, only a few randomized clinical trials have been performed involving MTX, and most of the current evidence comes from pivotal studies of biologic drugs. The aim of this article is to make an extensive review of the MTX mechanism of action, pharmacokinetics, efficacy, safety and tolerability, especially focusing on the future perspective of this old drug and recent advances in the field of pharmacogenetics.