What is the MOA for the immunologic effects of MTX at the doses currently used? MTX enters the cell via the reduced folate carrier (RFC) and leaves the cell via members of the ATP-binding cassette (ABC) protein family. Intracellular MTX undergoes polyglutamation by the enzyme folylpolyglutamate synthase (FPGS). Polyglutamation of MTX prevents intracellular MTX from …
When should a liver biopsy be performed on patients receiving MTX? Routine baseline or periodic liver biopsies in patients receiving MTX are not recommended. Usually when liver tests are persistently or significantly elevated in patients on MTX, the dose is reduced and reevaluation is performed. If the liver function tests continue to be significantly elevated, …
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Precautions and monitoring required for patients taking MTX Monitoring: before starting MTX, CBC with platelets, hepatitis B and C serologies, aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, and creatinine (CrCl) should be obtained. A chest x-ray should be performed if the patient has not had one in the past year. Monitor CBC, creatinine, and liver …
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What dose of MTX is used to treat Rheumatoid Arthritis and what toxicities are associated with its use? Dosage: 7.5 to 25 mg orally, subcutaneous, or intramuscular weekly. The absorption of oral and parenteral MTX is equivalent at doses <15 mg/week. At higher doses, parenteral MTX gives serum levels 30% higher than oral MTX. At …
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Role of MTX in Rheumatoid Arthritis MTX (Rheumatrex, Trexall) is considered the most effective DMARD for RA. Approximately 30% of patients will achieve low-disease activity on MTX monotherapy. MTX acts relatively quickly after being started, often within several weeks. In addition to its clinical efficacy, MTX retards new erosions in involved joints. Using other drugs (HCQ …
In what rheumatic diseases is SSZ used? • RA. • JIA. • Reactive arthritis (Reiter’s syndrome). • Psoriatic arthritis. • Ankylosing spondylitis (peripheral arthritis). • Enteropathic arthritis.
What is the metabolism and MOA of SSZ? Only 10% to 30% of SSZ is ultimately absorbed in the small intestine. Most SSZ is broken down by colonic bacteria to sulfapyridine, which is then 90% absorbed, and into 5-ASA, which mostly (90%) stays in the bowel. The sulfapyridine component is felt to be most effective …