Could any of these medications cause an elevated white blood cell count?

Medications That Can Cause Elevated WBC Count

Among this medication list, corticosteroids are the most common cause of leukocytosis, but none of these specific medications are present; however, cefepime (a beta-lactam antibiotic) paradoxically can cause leukocytosis as part of an inflammatory response, and albuterol (a beta-agonist) is a well-documented cause of elevated WBC counts. 1

Beta-Agonists and Leukocytosis

• Albuterol sulfate (beta-agonist) is a recognized cause of leukocytosis and should be considered as a potential contributor to elevated WBC counts 1
• Beta-agonists cause leukocytosis through demargination of white blood cells from the vascular endothelium, which can double the peripheral WBC count within hours 2
• This mechanism represents a benign, physiologic response rather than true bone marrow stimulation 2

Beta-Lactam Antibiotics

• Cefepime (a beta-lactam antibiotic) can paradoxically cause both neutropenia and reactive leukocytosis, depending on the clinical context 3
• Beta-lactam antibiotics more commonly cause neutropenia through immunologic mechanisms, but inflammatory responses to infection being treated can elevate WBC counts 3
• The patient is receiving cefepime for respiratory infection, and the infection itself is likely driving any leukocytosis rather than the antibiotic 1

Other Medications on This List

• Corticosteroids are the most common medication cause of leukocytosis, but none are present in this medication list 1
• Lithium is associated with leukocytosis, but the patient is not taking lithium 1
• Sertraline, mirtazapine, and buspirone (psychiatric medications on this list) are not documented causes of elevated WBC counts 1

Clinical Context for Interpretation

• Physical and emotional stress can elevate WBC counts independent of medications, including pain, anxiety, and acute illness 2, 1
• The patient is receiving fentanyl patches and lidocaine patches for chronic pain, suggesting an underlying condition that could contribute to stress-related leukocytosis 2
• Normal WBC range in hospitalized patients without infection extends up to 14.5 × 10⁹/L, higher than the traditional upper limit of 11 × 10⁹/L used for healthy outpatients 4

Common Pitfalls

• Do not assume leukocytosis is pathologic without considering the hospitalized patient's baseline, as 13.5% of hospitalized patients without infection have WBC counts between 11-14.5 × 10⁹/L 4
• Infection itself (for which cefepime is being given) is a far more likely cause of leukocytosis than the antibiotic 1
• Beta-agonist use (albuterol) should be documented as a potential contributor when evaluating leukocytosis, particularly if used frequently for wheezing 1