Safety and Tolerability of Subcutaneous Methotrexate in Routine Clinical Practice

Molecular mechanisms underlying methotrexate-induced intestinal injury and protective strategies

Methotrexate (MTX) is a folic acid reductase inhibitor that manages various malignancies as well as immune-mediated inflammatory chronic diseases. Despite being frequently prescribed, MTX's severe multiple toxicities can occasionally limit its therapeutic potential. Intestinal toxicity is a severe adverse effect associated with the administration of MTX, and patients are significantly burdened by MTX-provoked intestinal mucositis. However, the mechanism of such intestinal toxicity is not entirely understood, mechanistic studies demonstrated oxidative stress and inflammatory reactions as key factors that lead to the development of MTX-induced intestinal injury. Besides, MTX causes intestinal cells to express pro-inflammatory cytokines like interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), which activate nuclear factor-kappa B (NF-κB). This is followed by the activation of the Janus kinase/signal transducer and activator of the transcription3 (JAK/STAT3) signaling pathway. Moreover, because of its dual anti-inflammatory and antioxidative properties, nuclear factor erythroid-2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) has been considered a critical signaling pathway that counteracts oxidative stress in MTX-induced intestinal injury. Several agents have potential protective effects in counteracting MTX-provoked intestinal injury such as omega-3 polyunsaturated fatty acids, taurine, umbelliferone, vinpocetine, perindopril, rutin, hesperidin, lycopene, quercetin, apocynin, lactobacillus, berberine, zinc, and nifuroxazide. This review aims to summarize the potential redox molecular mechanisms of MTX-induced intestinal injury and how they can be alleviated. In conclusion, studying these molecular pathways might open the way for early alleviation of the intestinal damage and the development of various agent plans to attenuate MTX-mediated intestinal injury.

Oral Versus Subcutaneous Methotrexate in Immune-Mediated Inflammatory Disorders: an Update of the Current Literature

PURPOSE

This review aims to critically evaluate the potential benefit of either oral or subcutaneous administration of methotrexate (MTX) in various immune-mediated inflammatory disorders (IMIDs) through analysis of efficacy, toxicity, pharmacokinetics and pharmacodynamics of both administration routes.

RECENT FINDINGS

Recent studies comparing the efficacy of oral versus subcutaneous MTX administration in IMIDs have revealed contradicting results. Some reported higher efficacy with subcutaneous administration, while others found no significant difference. Regarding toxicity, some studies have challenged the notion that subcutaneous administration is better tolerated than oral administration, while others have supported this. Pharmacokinetic studies suggest higher plasma bioavailability and increased accumulation of MTX-polyglutamates (MTX-PGs) in red blood cells (RBCs) with subcutaneous administration during the initial treatment phase. However, after several months, similar intracellular drug levels are observed with both administration routes. There is no conclusive evidence supporting the superiority of either oral or subcutaneous MTX administration in terms of efficacy and adverse events in IMIDs. Subcutaneous administration leads to higher plasma bioavailability and initial accumulation of MTX-PGs in RBCs, but the difference seems to disappear over time. Given the variable findings, the choice of administration route may be based on shared decision-making, offering patients the option of either oral or subcutaneous administration of MTX based on individual preferences and tolerability. Further research is needed to better understand the impact of MTX-PGs in various blood cells and TDM on treatment response and adherence to MTX therapy.

Treatment of Discoid Lupus Erythematosus with Upadacitinib: A Case Report

Cutaneous lupus erythematosus (CLE) is a group of diseases within the spectrum of lupus that primarily manifests with skin lesions. Discoid lupus erythematosus (DLE) is the most common subtype of CLE. Currently, there is no specific medication available for the treatment of CLE. Here, we reported the efficacy and safety of upadacitinib, a JAK1 selective inhibitor, in treating one DLE patient for 28 weeks. Upadacitinib 15mg QD alone improved DLE lesions significantly, while reduction of the drug to 15mg QOD led to a relapse of the skin lesions. Upadacitinib showed favorable safety in this DLE patient in the 28-week period, except for acne, which was controlled by topical application of benzoyl peroxide gel. In this case, we observed rapid and sustained improvement of DLE lesions using upadacitinib with favorable safety, which provided the opportunity to use upadacitinib as an alternative therapy for DLE.

[Methotrexate treatment before use of biologics in rheumatoid arthritis : Analysis of guideline compliance]

BACKGROUND

With the introduction of biologics the treatment landscape for patients with rheumatoid arthritis (RA) has rapidly expanded; however, according to German and European treatment guidelines the use of biologic disease-modifying antirheumatic drugs (bDMARD) is only indicated after insufficient response under methotrexate (MTX) doses of at least 20 mg/week (first-line treatment). The aim of the study was to analyze the guideline compliance of MTX prescription in the outpatient sector prior to treatment with biologics.

MATERIAL AND METHODS

Claims data from the AOK Lower Saxony from 2013 to 2016 were provided for all insured patients with a diagnosis of RA and bDMARD prescription during the study period. Within a patient-specific observational period of 180 days prior to the first bDMARD prescription, the maximum prescribed MTX dosage was examined.

RESULTS

Data from 90 incident and 315 prevalent RA patients were analyzed. A maximum MTX prescription of < 20 mg/week was observed in 60.0% of incident patients and in 67.0% of prevalent patients. Men had a higher mean MTX maximum dose (17.1 ± 4.8 mg) than women (14.9 ± 5.0 mg; p < 0.0001). Of the study population 29.6% received oral only prescriptions during the observational period. In 12.4% of patients a switch to parenteral administration was made.

DISCUSSION

Targeted use of the full spectrum of therapies provided prior to initiation of bDMARD treatment may contribute to cost-effective RA care. This study showed indications for potential deficits in outpatient MTX prescription practice and can raise awareness for efficient treatment.

Researchers in rheumatology should avoid categorization of continuous predictor variables

BACKGROUND

Rheumatology researchers often categorize continuous predictor variables. We aimed to show how this practice may alter results from observational studies in rheumatology.

METHODS

We conducted and compared the results of two analyses of the association between our predictor variable (percentage change in body mass index [BMI] from baseline to four years) and two outcome variable domains of structure and pain in knee and hip osteoarthritis. These two outcome variable domains covered 26 different outcomes for knee and hip combined. In the first analysis (categorical analysis), percentage change in BMI was categorized as ≥ 5% decrease in BMI, < 5% change in BMI, and ≥ 5% increase in BMI, while in the second analysis (continuous analysis), it was left as a continuous variable. In both analyses (categorical and continuous), we used generalized estimating equations with a logistic link function to investigate the association between the percentage change in BMI and the outcomes.

RESULTS

For eight of the 26 investigated outcomes (31%), the results from the categorical analyses were different from the results from the continuous analyses. These differences were of three types: 1) for six of these eight outcomes, while the continuous analyses revealed associations in both directions (i.e., a decrease in BMI had one effect, while an increase in BMI had the opposite effect), the categorical analyses showed associations only in one direction of BMI change, not both; 2) for another one of these eight outcomes, the categorical analyses suggested an association with change in BMI, while this association was not shown in the continuous analyses (this is potentially a false positive association); 3) for the last of the eight outcomes, the continuous analyses suggested an association of change in BMI, while this association was not shown in the categorical analyses (this is potentially a false negative association).

CONCLUSIONS

Categorization of continuous predictor variables alters the results of analyses and could lead to different conclusions; therefore, researchers in rheumatology should avoid it.

The Safety of Antirheumatic Drugs

Background

Drug therapy for rheumatic diseases has changed fundamentally in recent decades with the introduction of many new agents. As these drugs may have to be taken for many years, and many of them are of similar efficacy, the safety profiles of the individual substances play an important role in therapeutic decision-making.

Method

This review is based on pertinent literature retrieved by a selective search on the safety profiles of selected antirheumatic drugs.

Results

Non-steroidal antirheumatic drugs, glucocorticoids, conventional disease-modifying drugs such as methotrexate, biological agents, and janus kinase (JAK) inhibitors are all used to treat rheumatic diseases. Register and trial data show that antirheumatic treatments are relatively safe. Infections, in particular, are much less common than initially expected. Cortisone administration is an exception because of its severe long-term sequelae. Biological agents are associated with severe infectious events at a rate of 4–5 events per 100 patient years. Screening before treatment with biological agents has been shown to lower the rate of tuberculosis from 564 to 95 cases per 100 000 patient years. JAK inhibitors have a good safety profile, with respect to infections as well, but there is evidence of their association with cardiovascular problems, malignancies, and thrombosis.

Conclusion

A suitable, safe antirheumatic drug can be chosen for each patient in consideration of individual risk profiles. Regular monitoring enables the early detection of adverse effects. The risk profile of JAK inhibitors, in particular, will be studied in further trials.

Pharmacomicrobiology of Methotrexate in Rheumatoid Arthritis: Gut Microbiome as Predictor of Therapeutic Response

Rheumatoid arthritis (RA) is a disabling autoimmune disease with invasive arthritis as the main manifestation and synovitis as the basic pathological change, which can cause progressive destruction of articular cartilage and bone, ultimately leading to joint deformity and loss of function. Since its introduction in the 1980s and its widespread use in the treatment of RA, low-dose methotrexate (MTX) therapy has dramatically changed the course and outcome of RA treatment. The clinical use of this drug will be more rational with a better understanding of the pharmacology, anti-inflammatory mechanisms of action and adverse reaction about it. At present, the current clinical status of newly diagnosed RA is that MTX is initiated first regardless of the patients’ suitability. But up to 50% of patients could not reach adequate clinical efficacy or have severe adverse events. Prior to drug initiation, a prognostic tool for treatment response is lacking, which is thought to be the most important cause of the situation. A growing body of studies have shown that differences in microbial metagenomes (including bacterial strains, genes, enzymes, proteins and/or metabolites) in the gastrointestinal tract of RA patients may at least partially determine their bioavailability and/or subsequent response to MTX. Based on this, some researchers established a random forest model to predict whether different RA patients (with different gut microbiome) would respond to MTX. Of course, MTX, in turn, alters the gut microbiome in a dose-dependent manner. The interaction between drugs and microorganisms is called pharmacomicrobiology. Then, the concept of precision medicine has been raised. In this view, we summarize the characteristics and anti-inflammatory mechanisms of MTX and highlight the interaction between gut microbiome and MTX aiming to find the optimal treatment for patients according to individual differences and discuss the application and prospect of precision medicine.