Sarcoidosis is a chronic inflammatory disease characterized by granulomas, tiny clumps of inflammatory cells that can affect various organs, most commonly the lungs. Methotrexate, an immunosuppressant, is frequently used to manage sarcoidosis. It helps control the immune system’s overactivity, reducing inflammation and symptoms by limiting granuloma formation.
Sarcoidosis and Methotrexate Basics
Sarcoidosis is a systemic disease where abnormal collections of inflammatory cells, known as granulomas, can develop in different tissues. While it often impacts the lungs, leading to symptoms like shortness of breath and a persistent cough, sarcoidosis can also affect the skin, eyes, joints, heart, and other organs.
Methotrexate is a medication classified as a disease-modifying anti-rheumatic drug (DMARD) that possesses both immunosuppressive and anti-inflammatory properties. Methotrexate works by interfering with cell division, particularly targeting fast-growing cells, which helps to modulate the immune response.
How Methotrexate Works for Sarcoidosis
Methotrexate manages sarcoidosis by modulating the immune system’s overactive response. It inhibits dihydrofolate reductase (DHFR), an enzyme necessary for DNA synthesis. By blocking DHFR, methotrexate slows the growth of rapidly dividing immune cells involved in sarcoidosis’s inflammatory process, reducing granuloma formation.
Its anti-inflammatory effects also reduce inflammation. Methotrexate is often a second-line treatment for sarcoidosis, particularly when corticosteroids are not sufficiently effective, cause severe side effects, or when a corticosteroid-sparing agent is desired. It can reduce dependency on corticosteroids or replace them.
Dosage, Administration, and Monitoring
Methotrexate is typically administered once weekly to minimize side effects. The usual dose ranges from 5 mg to 25 mg per week. Treatment often begins with a lower dose, which may be gradually increased until the desired therapeutic effect is achieved. Doses exceeding 25 mg per week are generally not recommended due to increased risk of side effects.
Methotrexate can be taken as oral tablets or via injection. Folic acid supplementation is often recommended to mitigate common side effects like nausea and mouth sores. Regular monitoring, including periodic blood tests for liver function, kidney function, and complete blood counts, is crucial to ensure safety and effectiveness.
Potential Side Effects and Safety Considerations
Methotrexate therapy can be associated with various side effects. Common, mild side effects include nausea, fatigue, and mouth sores. More serious, though less frequent, risks include liver damage, lung problems, and bone marrow suppression, which can lead to reduced blood cell counts and increased infection susceptibility.
Methotrexate can interact with other medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and certain antibiotics, potentially increasing methotrexate levels and side effect risk. It is contraindicated in pregnancy and in individuals with severe kidney or liver disease. Patients should promptly contact their healthcare provider if they experience signs of infection, persistent nausea, unusual fatigue, or other concerning symptoms.