Does Lovenox (enoxaparin) cause leukocytosis (elevated white blood cell count)?

Does Lovenox Cause Elevated White Blood Cells?

No, Lovenox (enoxaparin) is not typically associated with causing leukocytosis (elevated white blood cell count). While Lovenox has several known side effects, an increase in white blood cell count is not among its commonly reported adverse reactions.

Evidence Regarding Lovenox and Blood Cell Effects

Known Hematologic Effects of Lovenox

Lovenox (enoxaparin) is a low molecular weight heparin (LMWH) used primarily for:

• Prevention and treatment of deep vein thrombosis (DVT)
• Prevention and treatment of pulmonary embolism (PE)
• Prevention of thromboembolic events in various clinical scenarios 1

The documented hematologic effects of Lovenox include:

1. Bleeding complications - The most common and significant side effect 2
2. Thrombocytopenia - A well-recognized adverse effect 2
3. Rare cases of reactive thrombocytosis - Isolated case reports have documented increased platelet counts following enoxaparin administration 3, 4

However, leukocytosis (elevated white blood cell count) is not listed among the known adverse effects in clinical guidelines or drug information.

Clinical Context for Elevated WBC Count

When evaluating elevated white blood cell counts in patients receiving Lovenox, clinicians should consider:

1. Underlying disease process - Many conditions requiring anticoagulation may themselves cause leukocytosis

   • Acute coronary syndromes
   • Infections
   • Inflammatory conditions
   • Cancer

2. Khorana risk model - This model actually uses elevated pre-chemotherapy leukocyte count (>11 × 10^9/L) as a risk factor for VTE in cancer patients, not as an effect of anticoagulation 2

3. Other medications - Consider other drugs the patient may be taking that could cause leukocytosis

Monitoring Recommendations

For patients on Lovenox therapy:

• Regular monitoring of complete blood counts is recommended, particularly in the first 2-3 days of therapy and then every 2 weeks thereafter 2
• Focus monitoring on:
  • Hemoglobin and hematocrit (for bleeding)
  • Platelet count (for thrombocytopenia)
  • Signs of bleeding or bruising

Alternative Explanations for Leukocytosis

If a patient on Lovenox develops leukocytosis, consider these more likely explanations:

1. Infection - The most common cause of leukocytosis
2. Inflammatory response to the underlying condition
3. Stress response - Particularly in hospitalized patients
4. Other medications - Steroids, epinephrine, lithium, and others can cause leukocytosis
5. Hematologic disorders - Primary bone marrow disorders

Conclusion

Based on the available evidence, Lovenox is not known to cause elevated white blood cell counts. If leukocytosis is observed in a patient receiving Lovenox, clinicians should investigate other causes rather than attributing it to the medication itself. The primary hematologic concerns with Lovenox remain bleeding risk and the potential for thrombocytopenia.