CPT® Code 80220

The CPT® Code 80220 refers to a laboratory test specifically designed to monitor therapeutic levels of hydroxychloroquine, which is classified as an aminoquinoline and immunosuppressive medication. Hydroxychloroquine is primarily utilized in the treatment and prevention of malaria, as well as in managing autoimmune conditions such as systemic lupus erythematosus and rheumatoid arthritis. Additionally, it has been employed for various off-label uses, including treatment for Q fever and potential applications in COVID-19 management. It is crucial to adhere to the recommended dosage guidelines, which stipulate that the daily intake should not exceed 5 mg per kilogram of body weight. This therapeutic drug assay is essential for measuring the concentration of hydroxychloroquine in the blood, allowing healthcare providers to determine whether toxicity levels are present and to evaluate the associated risk of retinal damage, a known side effect of the medication. The test requires a separately reportable venous blood sample, and while whole blood is traditionally used for testing due to its precision, serum or plasma may also be utilized. It is important to note that drug concentrations can vary significantly among individuals who are on the same dosage regimen, and these concentrations do not necessarily correlate with clinical effectiveness. Target therapeutic ranges for hydroxychloroquine differ depending on the specific condition being treated, with ocular toxicity being a critical concern at levels ranging from 1,177 to 3,503 ng/mL. Various factors, including renal filtration rates, body mass index, genetic differences, and patient adherence to prescribed regimens, can influence the concentration levels of the drug in the bloodstream. Most laboratories employ advanced testing methods such as liquid chromatography mass spectrometry (LC-MS) or liquid chromatography-high-resolution mass spectrometry (LC-HRMS) to ensure accurate measurement of hydroxychloroquine levels.