Dexamethasone‑Induced Leukocytosis: Clinical Impact and Management

Dose‑Dependent Lymphopenia

Dexamethasone exerts a markedly stronger lymphocyte‑suppressing effect than hydrocortisone, being roughly ten times more potent in inducing lymphopenia, and this effect intensifies with higher cumulative doses. 1

According to the National Comprehensive Cancer Network (NCCN) guidelines, high‑dose dexamethasone regimens are associated with greater toxicity than low‑dose regimens, leading to inferior survival partly because of a higher incidence of pneumonia (approximately 16 % vs 9 % with low‑dose therapy). 2
NCCN guidance notes that dexamethasone‑induced leukocytosis does not reflect enhanced immune competence; instead, it signifies immunosuppression and an elevated risk of infections, particularly pneumonia. 2

Grade ≥ 3 lymphopenia occurs in roughly 25 %–63 % of patients receiving dexamethasone‑containing cancer regimens, underscoring the need for regular complete blood count monitoring. 1
Clinical recommendations advise using the lowest effective dexamethasone dose, as low‑dose regimens have been shown to provide superior overall survival despite achieving lower tumor response rates. 1