From the Guidelines
Mabtera, also known as methotrexate, is a medication that should be prescribed at a dose of 7.5 to 25 mg weekly, with the goal of reaching 25 mg per week as the optimal dose, and with folate supplementation to minimize adverse effects, as recommended by the most recent guidelines 1. The dosing and scheduling of methotrexate are crucial to its effectiveness and safety.
- Methotrexate is usually given as a single weekly dose, with a dose range of 7.5 to 25 mg weekly for patients with atopic dermatitis or psoriasis 1.
- The average time to maximum effect is around 10 weeks, with minimal to no further efficacy after 12 to 16 weeks with further dose escalation 1.
- Folate supplementation is recommended to reduce the incidence of adverse effects, such as gastrointestinal side effects, elevated liver function tests, and drug discontinuation 1.
- Patients should be monitored regularly for potential complications, including liver toxicity, bone marrow suppression, and hematological effects 1.
- Methotrexate has been shown to be effective in treating psoriatic arthritis, with a similar efficacy to biologic agents such as etanercept 1.
- The medication should be prescribed with caution, taking into account the patient's medical history, concomitant medications, and potential drug interactions 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Mabtera (Methotrexate) Overview
- Methotrexate is a medication used to treat various disorders, including psoriasis, rheumatoid arthritis, and certain types of cancer 2, 3.
- The use of methotrexate has been limited by concerns regarding its adverse effects, including hepatotoxicity 2.
Hepatotoxicity and Liver Disease Risk
- Patients with psoriatic disease may be more susceptible to methotrexate hepatotoxicity than those with rheumatoid arthritis 4.
- The incidence rate of liver disease was found to be greatest for patients with psoriasis, followed by psoriatic arthritis, and lowest for rheumatoid arthritis 4.
- Elevated liver enzyme tests were found in 22% of patients with rheumatoid arthritis receiving methotrexate, and 31% of patients receiving a combination of methotrexate and leflunomide 5.
Toxicity and Side Effects
- Methotrexate can produce toxicity and side effects such as bone marrow suppression, pulmonary toxicity, nephrotoxicity, hematologic toxicity, and an increased risk of infections 3.
- High-dose methotrexate (HD-MTX) can be more beneficial but also increases the risk of toxicity and side effects 3.
- Leucovorin is highly beneficial in preventing myelosuppression, gastric toxicity, and neurotoxic effects after HD-MTX therapy 3.
Monitoring and Treatment
- Monitoring for potential hepatotoxicity is essential in patients receiving methotrexate, particularly in those with psoriatic disease 4, 5.
- Treatment of severe methotrexate toxicity has three main goals: clearance of methotrexate from the bloodstream, folinic acid therapy, and organ treatment 3.
- Glucarpidase has been licensed for the treatment of high plasma methotrexate levels in patients with compromised renal function 3.