Occurrence of thrombocytopenia in psychiatric patients taking valproate.
OBJECTIVE
Few studies, with conflicting results, have examined the occurrence of thrombocytopenia with valproate administration. This study assessed whether the platelet-lowering effects of valproate are increased among elderly psychiatric patients.


METHODS
The charts of 39 psychiatric inpatients taking valproate were reviewed. Information on hematologic function and on doses and serum levels of valproate at sequential intervals over a 12-month period was abstracted. Data for subjects age <60 years (nonelderly subjects) and those age >/=60 years (elderly subjects) were compared.


RESULTS
More than half (53.8%) of the elderly patients but only 13.0% of the nonelderly patients had at least one episode of thrombocytopenia. This difference corresponded to a significantly greater lowering of platelet counts among elderly patients than among nonelderly patients.


CONCLUSIONS
The high rate of thrombocytopenia in our study suggests the need for routine monitoring of platelet counts among patients taking valproate, particularly among elderly patients.
Trannel
T J
TJ
Hawaii State Psychiatric Hospital, Kaneohe, Hawaii, USA. ttrannel@gundluth.org
Ahmed
I
I
Goebert
D
D
D000367:Age Factors; D000368:Aged; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use; D016903:Drug Monitoring; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000188:drug therapy* / Q000523:psychology; D008875:Middle Aged; D010976:Platelet Count; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced*; D014635:Valproic Acid / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use
D000927:Anticonvulsants; D014635:Valproic Acid