Drugs That Can Cause Leukocytosis of 12.8
Corticosteroids are the most common medication cause of mild to moderate leukocytosis with WBC counts around 12.8 × 10^9/L, typically producing increases of 2.4-4.8 × 10^9/L within 48 hours of administration. 1
Common Medication Causes of Leukocytosis
Corticosteroids
- Prednisone and other corticosteroids can cause significant leukocytosis even at low doses 2
- The effect is dose-dependent with higher doses causing more pronounced leukocytosis 1, 2
- Peak effect typically occurs within 48 hours after administration 1
- Leukocytosis is predominantly due to increased neutrophils, often with concurrent monocytosis, eosinopenia, and variable lymphopenia 2
- Even small doses administered over prolonged periods can induce persistent leukocytosis 2
Other Common Medications
- Beta-agonists can cause mild to moderate leukocytosis 3
- Lithium therapy is associated with leukocytosis 3
- Carbamazepine has been reported to cause significant leukocytosis that resolves upon discontinuation 4
Distinguishing Medication-Induced from Pathologic Leukocytosis
Key Differentiating Features
- Medication-induced leukocytosis typically lacks a "left shift" (increased immature neutrophil forms) 2
- Toxic granulation in neutrophils is rare in medication-induced leukocytosis but common in infection 2
- In corticosteroid-induced leukocytosis, increases of up to 4.84 × 10^9/L within 48 hours are expected with high-dose therapy 1
- Larger increases, particularly after low-dose steroids, suggest other causes 1
When to Suspect Other Causes
- Extremely elevated white blood cell counts (>100 × 10^9/L) suggest hyperleukocytosis, which is a medical emergency requiring immediate intervention 3, 5
- Concurrent abnormalities in red blood cell or platelet counts may indicate a primary bone marrow disorder 3
- Presence of constitutional symptoms (weight loss), bleeding/bruising, or organomegaly (liver, spleen, lymph nodes) increases suspicion for malignancy 3
Management Considerations
For Medication-Induced Leukocytosis
- If the leukocytosis is determined to be medication-induced and the medication is necessary, monitoring without specific intervention is usually appropriate 1, 2
- In cases where the medication can be safely discontinued or substituted, the WBC count typically normalizes within days 4
For Hyperleukocytosis (WBC >100,000/μL)
- Requires immediate intervention due to risk of brain infarction and hemorrhage 3
- Aggressive intravenous hydration (2.5-3 liters/m²/day) 5
- Consider hydroxyurea (50-60 mg/kg/day) to rapidly reduce white blood cell counts 6, 5
- Monitor for and prevent tumor lysis syndrome 5
Special Considerations
- In patients with suspected leukemia and elevated WBC counts, prompt institution of definitive therapy is essential 7
- Avoid invasive procedures in patients with severe neutropenia due to risk of hemorrhagic complications 7
- For patients with acute leukemia, treatment should be directed at the underlying malignancy according to specific protocols 7