Does methylprednisolone (Solumedrol) affect cortisol level testing?

From the Guidelines

Yes, Solumedrol (methylprednisolone) significantly affects cortisol level testing, and patients should postpone testing until at least after the treatment course is completed, considering the dose and duration of treatment. The impact of methylprednisolone on cortisol testing is multifaceted, involving both direct interference with laboratory measurements and suppression of the body's natural cortisol production through the hypothalamic-pituitary-adrenal axis 1. This suppression can occur with daily glucocorticoid doses equivalent to prednisolone ≥ 5 mg for longer than 1 month, affecting a proportion of adults by representing an adrenal suppressive dose 1.

Given the variability in patient response and the potential for significant suppression, it's crucial to consider the dose, duration, and individual patient factors when assessing the need for cortisol testing in patients on Solumedrol. Some studies suggest that approximately one third to a half of patients on 5 mg or more of prednisolone daily may not achieve target cortisol concentrations, highlighting the potential for inadequate adrenal cortisol reserve in a significant number of patients 1.

Key considerations for clinicians include:

• The dose and duration of Solumedrol treatment
• The individual patient's condition and physiological stress level
• The potential for cross-reactivity with cortisol assays and suppression of natural cortisol production
• The need for specialized testing methods if accurate cortisol assessment is crucial while the patient is on Solumedrol

In clinical practice, if cortisol testing is urgently needed for a patient on Solumedrol, it's essential to note this on the laboratory requisition and interpret results with caution, understanding that values will likely be affected by the treatment 1. The guidance from recent studies supports balanced, individualized glucocorticoid supplementation during periods of physiological stress, considering the risks of inadequate glucocorticoid response and the lack of long-term harm from short-term supplementation 1.

From the Research

Methylprednisolone and Cortisol Level Testing

• Methylprednisolone, also known as Solumedrol, is a corticosteroid that can affect cortisol levels in the body 2.
• Studies have shown that high-dose intravenous Solumedrol treatment can improve 28-day survival in patients with sepsis who have a blunted cortisol response to adrenocorticotropic hormone (ACTH) stimulation 2.
• However, the use of Solumedrol can also suppress the hypothalamic-pituitary-adrenal (HPA) axis, leading to adrenal insufficiency 3.
• The adrenocorticotropic hormone stimulation test (ACTH-ST) is commonly used to diagnose adrenal insufficiency, but its effectiveness can be compromised by high-dose glucocorticoid therapy 3.
• Research suggests that the ACTH-ST can still be used to diagnose adrenal insufficiency within the first 3 days after initiation of empiric glucocorticoid therapy, but the results should be interpreted with caution 3.

Cortisol Level Testing and Adrenal Insufficiency

• Morning serum cortisol (MSC) has been proposed as a screening test for adrenal insufficiency, with a cutoff value of 234.2 mmol/L showing high sensitivity and specificity 4.
• However, the accuracy of MSC as a screening test can be affected by various factors, including the use of glucocorticoids such as Solumedrol 4.
• The diagnosis of adrenal insufficiency is complex and requires careful interpretation of laboratory results, including the ACTH-ST and MSC 5, 6.
• Further studies are needed to confirm the optimal cutoff values for MSC and to evaluate the effectiveness of MSC as a screening test for adrenal insufficiency in different populations 4.

Limitations and Considerations

• The studies reviewed had limitations, including small sample sizes and variability in study design and population 2, 5, 6, 3, 4.
• The results of these studies should be interpreted with caution, and further research is needed to fully understand the effects of Solumedrol on cortisol level testing and adrenal insufficiency diagnosis 2, 5, 6, 3, 4.