CPT® Code 80204

The CPT® Code 80204 refers to a laboratory test specifically designed to monitor therapeutic levels of methotrexate, which is a medication utilized in chemotherapy and immunosuppressive therapy. Methotrexate is commonly prescribed for various conditions, including different types of cancer such as breast, bone, blood, lung, head, and neck cancers. Additionally, it is employed in the treatment of autoimmune disorders like rheumatoid arthritis (RA) and psoriasis. The drug functions by inhibiting the growth of cancer cells, suppressing the immune response, and slowing the production of new skin cells, which is particularly beneficial in managing inflammatory arthritis. Regular monitoring through this laboratory test is crucial, especially after administering high doses of methotrexate, as it helps in detecting and tracking blood concentration levels to identify potential toxic effects that may impact vital organs such as the liver, kidneys, lungs, or bone marrow. The testing process involves drawing a venous blood sample, which is then analyzed using an enzyme immunoassay technique. The results obtained from this test are compared against established reference values indicative of healthy individuals, with particular attention given to serum concentrations that may indicate clinical toxicity, specifically when levels exceed 10 umol/L at 24 hours, 1 umol/L at 48 hours, and 0.1 umol/L at 72 hours post-administration.