Leukopenia Associated with Paroxetine Use

Abstract

Objective:

To report a case of leukopenia associated with paroxetine treatment.

Case Summary:

A 44-year-old white female with a history of anemia secondary to heavy menses, anxiety, depression, and current tobacco dependence presented with general symptoms of fatigue and blurred vision. The patient's medications at the time of the initial visit were ferrous sulfate 325 mg twice a day and paroxetine 20 mg/day. Three years prior to the initiation of paroxetine, the patient's documented white blood cell (WBC) count was 7.4 × 10³/μL with normal differential and hemoglobin was 10.5 g/dL; on presentation, laboratory test results were WBC count 1.3 × 10³/μL, red blood cell count 1.78 × 10⁶/μL, hemoglobin 4.5 g/dL, hematocrit 15.1%, and platelets 248 × 10³/μL. Three months after discontinuation of paroxetine, the patient's WBC count was 4.4 × 10³/μL.

Discussion:

Paroxetine and other antidepressants have not been known to cause adverse hematologic effects that can be seen with other antipsychotics, namely, clozapine. The use of the Naranjo probability scale indicated a probable relationship between leukopenia and paroxetine therapy in this patient. Based on a MEDLINE search (February 12, 2007), there are limited data on leukopenia as an adverse event of paroxetine. We found this to be a unique case of leukopenia suspected to be secondary to extended use of low-dose paroxetine.

Conclusions:

Although leukopenia caused by paroxetine and other medications with serotonergic effects appears to be uncommon, physicians and pharmacists should be aware of this rare but potentially serious adverse event.