Methotrexate is a systemic anti-cancer drug that can reduce the overproduction of cells, which is helpful in the treatment of psoriasis. However, it has conflicting research concerning its effectiveness despite its use during the last three decades. The long-term adverse effects of methotrexate are well known. The most frequent adverse effects that occur during methotrexate therapy are abnormal liver function test results, nausea, and gastric complaints. The most feared adverse effects are liver damage and the suppression of bone marrow activity. However, liver problems associated with methotrexate are related to a high cumulative dose. This means that rotating types of therapy, or using methotrexate intermittently instead of continuously, can reduce the risk. Most people tolerate low-dose methotrexate therapy relatively well, provided they work closely with their physician and watch carefully for adverse effects and drug interactions during treatment. (Sources: Clinical Rheumatology, 2001, volume 20, issue 6, pages 406-410; and American Journal of Clinical Dermatology, January-February 2000, pages 27-39.)
In the area of new options for psoriasis, methotrexate has been shown to be less beneficial than adalimumab, etanercept, efalizumab, and infliximab, but because it the least expensive it can still be a good option to start with if systemic therapy is being considered. (Sources: British Journal of Dermatology, 2008, www. BJD. org; and Clinical Experimental Dermatology, August 2008, pages 551-554.)