<P> Pseudoleukopenia can develop upon the onset of infection . The leukocytes (predominately neutrophils, responding to injury first) start migrating toward the site of infection, where they can be scanned . Their migration causes bone marrow to produce more WBCs to combat infection as well as to restore the leukocytes in circulation, but as the blood sample is taken upon the onset of infection, it contains low amount of WBCs, which is why it is termed "pseudoleukopenia". </P> <P> Certain medications can alter the number and function of white blood cells . </P> <P> Medications that can cause leukopenia include clozapine, an antipsychotic medication with a rare adverse effect leading to the total absence of all granulocytes (neutrophils, basophils, eosinophils). The antidepressant and smoking addiction treatment drug bupropion HCl (Wellbutrin) can also cause leukopenia with long - term use . Minocycline, a commonly prescribed antibiotic, is another drug known to cause leukopenia . There are also reports of leukopenia caused by divalproex sodium or valproic acid (Depakote), a drug used for epilepsy (seizures), mania (with bipolar disorder) and migraine . </P> <P> The anticonvulsant drug, lamotrigine, has been associated with a decrease in white blood cell count . </P>

What medications cause low white blood cell count