What dose of folic acid to use with methotrexate in rheumatoid arthritis?

Methotrexate for the neurologist

The use of methotrexate in clinical practice has expanded significantly in recent years, as an effective chemotherapeutic agent as well as disease-modifying treatment for conditions such as rheumatoid arthritis, psoriasis and Crohn's disease. It is also used as a steroid-sparing agent for a range of inflammatory diseases of the central and peripheral nervous systems. Clinical neurologists must, therefore, know how to start and uptitrate methotrexate, its monitoring requirements and its potential toxicities. This review aims first to explore the evidence base for using methotrexate in various neurological diseases and second to discuss important practicalities around its use, ensuring its safe application and appropriate monitoring.

Mechanisms underlying dose-limiting toxicities of conventional chemotherapeutic agents

Dose-limiting toxicities (DLTs) are severe adverse effects that define the maximum tolerated dose of a cancer drug. In addition to the specific mechanisms of each drug, common contributing factors include inflammation, apoptosis, ion imbalances, and tissue-specific enzyme deficiencies. Among various DLTs are bleomycin-induced pulmonary fibrosis, doxorubicin-induced cardiomyopathy, cisplatin-induced nephrotoxicity, methotrexate-induced hepatotoxicity, vincristine-induced neurotoxicity, paclitaxel-induced peripheral neuropathy, and irinotecan, which elicits severe diarrhea. Currently, specific treatments beyond dose reduction are lacking for most toxicities. Further research on cellular and molecular pathways is imperative to improve their management. This review synthesizes preclinical and clinical data on the pharmacological mechanisms underlying DLTs and explores possible treatment approaches. A comprehensive perspective reveals knowledge gaps and emphasizes the need for future studies to develop more targeted strategies for mitigating these dose-dependent adverse effects. This could allow the safer administration of fully efficacious doses to maximize patient survival.

Nutritional Aspects of Juvenile Idiopathic Arthritis: An A to Z for Dietitians

Juvenile idiopathic arthritis (JIA) represents a chronic, autoimmune, rheumatic musculoskeletal disease with a diagnosis before 16 years of age. Chronic arthritis is a common manifestation in all JIA subtypes. The nature of JIA, in combination to its therapy often results in the development of nutrition-, gastrointestinal (GI)- or metabolic-related issues. The most-common therapy-related nutritional issues involve methotrexate (MTX) and glucocorticosteroids (GCC) adverse events. MTX is a folic acid antagonist, thus supplementation with folic acid in required for improving GI side effects and correcting low serum levels. On the other hand, long-term GCC administration is often associated with hyperglycemia, insulin resistance and growth delay. This relationship is further aggravated when more joints are affected and greater doses of GCC are being administered. Apart from stature, body mass index z-scores are also suboptimal in JIA. Other signs of malnutrition include decreased phase angle and muscle mass, especially among patients with polyarthritis JIA. Evidence also points to the existence of an inverse relationship between disease activity and overweight/obesity. Specific dietary patterns, including the anti-inflammatory diet, might confer improvements in selected JIA outcomes, but the level of available research is yet insufficient to draw safe conclusions. The majority of patients exhibit suboptimal vitamin D status; hence, supplementation is recommended. Collectively, the evidence indicates that, due to the age of onset and the complexity of the disease, along with its pharmacotherapy, children with JIA are prone to the development of several nutritional problems, warranting expert monitoring. Vitamin deficiencies, oral and GI-problems limiting dietary intake, faltering growth, overweight and obesity, physical inactivity, or impaired bone health are among the many nutritional issues in JIA requiring dietitian support.

Methotrexate in inflammatory bowel disease: A primer for gastroenterologists

Methotrexate is an antineoplastic agent that is also used at lower doses for anti-inflammatory properties. Along with thiopurines (azathioprine and 6-mercaptopurine), it has historically been an important part of pharmacological treatment for patients with inflammatory bowel disease. Despite an increase in therapeutic options, these immunomodulators continue to play important roles in the management of inflammatory bowel disease, used either as a monotherapy in mild to moderate cases or in combination with monoclonal antibodies to prevent immunogenicity and maintain efficacy. In light of data linking the use of thiopurines with the risk of malignancies, methotrexate has regained attention as a potential alternative. In this article, we review data on the pharmacology, safety, and efficacy of methotrexate and discuss options for the positioning of methotrexate alone, or in combination, in therapeutic algorithms for Crohn's disease and ulcerative colitis.