Can any of my medications cause leukocytosis?

Medications That Can Cause Leukocytosis (High WBC Count)

Direct Answer

Among your medication list, corticosteroids (including Triamcinolone), Tacrolimus, and potentially Methotrexate are the most likely culprits for causing leukocytosis, while most of your other medications are not typically associated with elevated white blood cell counts. 1, 2

Medications Known to Cause Leukocytosis

Corticosteroids (Triamcinolone)

• Corticosteroids are among the most common medications causing leukocytosis, with dose-dependent effects on white blood cell counts 1, 2
• High-dose corticosteroids can increase WBC count by up to 4.84 × 10⁹/L within 48 hours of administration 2
• Medium-dose steroids typically cause a mean increase of 1.7 × 10⁹/L, while low-dose steroids cause approximately 0.3 × 10⁹/L increase 2
• The WBC response peaks at 48 hours after steroid administration, with a mean increase of 2.4 × 10⁹/L across all doses 2
• If you are using topical Triamcinolone at typical dermatologic doses, systemic absorption is usually minimal and unlikely to cause significant leukocytosis 1

Tacrolimus (Immunosuppressant)

• Tacrolimus itself does not directly cause leukocytosis; however, immunosuppression from Tacrolimus increases infection risk, which is a common cause of elevated WBC counts 3, 1
• Infections are the most common cause of leukocytosis in immunosuppressed patients, occurring in 53% of hospitalized patients with WBC ≥15,000 cells/mm³ 4
• Patients on immunosuppressants like Tacrolimus require monitoring for opportunistic infections that could manifest as leukocytosis 3

Methotrexate

• Methotrexate typically causes leukopenia (low WBC), not leukocytosis 3, 5
• However, if Methotrexate causes bone marrow suppression followed by rebound, or if it leads to infection due to immunosuppression, secondary leukocytosis could occur 3, 5
• Regular CBC monitoring is essential with Methotrexate to detect hematologic abnormalities early 3, 5

Medications Unlikely to Cause Leukocytosis

Medications That Cause Leukopenia (Opposite Effect)

• Methotrexate, Azathioprine (not on your list), and other immunosuppressants typically cause leukopenia, not leukocytosis 3, 6
• Trimethoprim-containing medications and Ganciclovir are associated with leukopenia 6

Medications With No Significant WBC Effect

• Gabapentin, Zetia (ezetimibe), Acetaminophen, Vitamin D3, Amlodipine, Atorvastatin, Multivitamins, Doxepin, Folic Acid, Famotidine, Loperamide, Aspirin, Cetirizine, Spironolactone, and Furosemide are not typically associated with leukocytosis 1, 7
• Anoro Ellipta (umeclidinium/vilanterol) contains a beta-agonist component (vilanterol), and beta-agonists can occasionally cause mild leukocytosis, though this is uncommon at therapeutic doses 1

Clinical Approach to Your Leukocytosis

Immediate Considerations

• First, determine if the leukocytosis is due to infection, which is the most common cause in patients on immunosuppression 1, 4
• Look for fever, localizing symptoms (cough, dysuria, diarrhea, wound changes), or signs of systemic infection 7, 4
• Consider Clostridium difficile infection if WBC >30,000 cells/mm³, as it accounts for 25% of cases with markedly elevated counts, even without diarrhea 4

Medication-Related Assessment

• If using topical Triamcinolone, systemic absorption is minimal unless applied to large body surface areas or under occlusion 1
• If recently started or increased dose of any corticosteroid, expect WBC elevation within 48 hours 2
• Review Tacrolimus levels and assess for signs of over-immunosuppression predisposing to infection 3

Other Common Causes to Exclude

• Physical or emotional stress can double WBC count within hours due to demargination of neutrophils from vessel walls 1, 7
• Recent surgery, trauma, exercise, or acute medical illness can cause reactive leukocytosis 1, 7
• Smoking and obesity are chronic causes of mild leukocytosis 7

Red Flags Requiring Urgent Evaluation

• WBC count >100,000 cells/mm³ represents a medical emergency due to risk of brain infarction and hemorrhage 1
• Concurrent abnormalities in red blood cells or platelets suggest primary bone marrow disorder 1, 7
• Constitutional symptoms (fever, weight loss, night sweats, bruising, fatigue) raise concern for hematologic malignancy 7, 8
• Lymphadenopathy, hepatosplenomegaly, or unexplained bleeding warrant hematology referral 1, 7

Monitoring Recommendations

• Obtain a complete blood count with differential to assess which WBC subtypes are elevated 7, 8
• Review peripheral blood smear for toxic granulations, immature cells, or abnormal cell morphology 7, 8
• If no clear infectious or stress-related cause is identified and leukocytosis persists, consider hematology consultation 7, 8
• For patients on Tacrolimus and Methotrexate, maintain regular CBC monitoring as per guideline recommendations 3, 5