Prednisone Concentration in Plasma (Quantitative)

Why This Test Is Done

Your healthcare provider may order this test if you’re taking prednisone for conditions like inflammation, autoimmune diseases, or allergies. It helps check whether your dose is working as intended and adjusts it if needed to avoid side effects like high blood pressure or weakened immunity.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if your lab uses a specific method, but this is rare for prednisone testing. Bring a list of all medications, including over-the-counter drugs and supplements, to share with your provider.

What the Test Involves

A healthcare professional will draw blood from a vein in your arm. The blood sample is then sent to a lab for analysis. The test measures prednisone concentration in your plasma, which reflects your current medication levels in your body.

What the Results Mean

Results are typically reported in micrograms per deciliter (µg/dL) or nanograms per milliliter (ng/mL). Your provider will compare these results to your target range based on your treatment plan. Low levels may indicate your dose needs adjustment, while high levels could signal side effects or improper dosing.