Subscribe Now/Learn More
PsychiatryOnline subscription options offer access to the
DSM-5 library, books,
journals, CME, and patient resources. This all-in-one virtual library provides psychiatrists
and mental health professionals with key resources for diagnosis, treatment, research,
and professional development.
Need more help? PsychiatryOnline Customer Service may be reached by emailing PsychiatryOnline@psych.org
or by calling 800-368-5777 (in the U.S.) or 703-907-7322 (outside the U.S.).
white blood cell (WBC) count must be greater than 3,500/mm3,
and absolute neutrophil count (ANC) must be greater than 2,000/mm3.
WBC count and ANC are required for the first 6 months of treatment
and for 4 weeks after discontinuation of clozapine. After 6 months, monitoring
is required every 2 weeks; and after 12 months, monitoring is required
every 4 weeks.
WBC count is 2,000–3,000/mm3 or
ANC is 1,000–1,500/mm3,
interrupt therapy and monitor for signs of infection. Perform WBC
and differential counts daily. If no symptoms of infection are seen,
if WBC count returns to greater than 3,000/mm3,
and if ANC is greater than 1,500/mm3,
resume clozapine therapy with twice-weekly WBC and differential
counts until total WBC count returns to more than 3,500/mm3 and ANC
is greater than 2,000/mm3.
WBC count is less than 2,000/mm3 or
ANC is less than 1,000/mm3,
discontinue clozapine and do not rechallenge. Perform WBC and differential
counts daily until WBC count is greater than 3,000/mm3 and ANC
is greater than 1,500/mm3.
Then monitor twice weekly until WBC count returns to more than 3,500/mm3 and
ANC is greater than 2,000/mm3.
Then monitor weekly for 4 weeks. Treat any infection with antibiotics.
Consider bone marrow aspiration to ascertain granulopoietic status.
If granulopoiesis is deficient, consider protective isolation.
from Marangell LB, Martinez JM: Concise Guide to
Psychopharmacology, 2nd Edition. Arlington, VA, American
Psychiatric Publishing, 2006, p. 112. Used with permission.