From the Research
The recommended washout period for prednisone before testing inflammatory markers is at least 24 hours, as concentrations of most metabolites are lower than 30 ng/ml from 24 hours after oral administration, according to the study published in 2021 1. This timeframe allows the body to clear the medication and for inflammatory markers to return to their baseline levels.
- Prednisone and other corticosteroids powerfully suppress inflammation by inhibiting cytokine production and immune cell function, which directly lowers inflammatory markers like C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and interleukin-6.
- Testing while on prednisone or too soon after discontinuation can lead to falsely low readings that don't accurately reflect the underlying disease activity.
- The washout period may need to be longer in patients with renal impairment, the elderly, or those who have been on very high doses or prolonged therapy.
- If inflammatory marker testing is urgently needed and cannot wait for the full washout period, clinicians should interpret results with caution, understanding that values may be artificially suppressed by recent corticosteroid use, as shown in studies such as 2, 3, and 4. However, the most recent and highest quality study, 1, provides the most relevant information for determining the washout period. In clinical practice, the selection of inflammatory markers should be based on the clinical condition, with consideration of their dynamics and limitations, as discussed in 5.