Mechanisms of action of methotrexate.

As one of the most utilized disease-modifying anti-rheumatic drugs, methotrexate (MTX) has revolutionized the treatment of rheumatoid arthritis as well as many other non-rheumatic chronic inflammatory diseases. Far from a simple anti- proliferative agent as was once thought, our understanding of how it exerts its anti-inflammatory effects has grown over the years. The mechanisms of action of MTX are reviewed here, and we look at how this knowledge helps to explain some of its most common side effects.