Risk of neuroleptic malignant syndrome in patients with bipolar disorder: a retrospective, population-based case-control study.
BACKGROUND
Current data regarding risk factors of neuroleptic malignant syndrome (NMS) are limited. This study aims to examine factors associated with increased risk of NMS in patients with bipolar disorder.


METHODS
A retrospective, population-based, case-control study was performed using a medical claims database covering January 1998 to December 2002. Fifty cases with a diagnosis of NMS were identified and matched with 800 controls. Conditional logistic regression analysis was used to estimate crude and adjusted odds ratios (ORs) of risk of NMS.


RESULTS
Antipsychotic use was associated with an increased risk of NMS after controlling for other pharmacologic and clinical factors (OR = 2.36, 95% CI = 1.08-5.19). Other factors associated with an increased risk of NMS included being male (OR = 2.07, 95% CI = 1.07-4.02), confusion (OR = 2.91, 95% CI = 1.17-7.28), dehydration (OR = 3.99, 95% CI = 1.50-10.57), delirium (OR = 4.93, 95% CI = 2.07-11.72), and extrapyramidal symptoms (OR = 3.50, 95% CI = 1.10-11.09).


CONCLUSIONS
Given the widespread use of antipsychotics for the treatment of bipolar disorder, clinicians should be vigilant of the potential pharmacologic and clinical factors associated with increased risk of NMS in patients with bipolar disorder.
Chen
Yan
Y
Department of Pharmacy Practice and Administrative Sciences, School of Pharmacy, University of Cincinnati Medical Center, Ohio 45267-0004, USA. yance@email.uc.edu
Guo
Jeff J
JJ
Steinbuch
Michael
M
Buckley
Peter F
PF
Patel
Nick C
NC
D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000453:epidemiology*; D016022:Case-Control Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008329:Managed Care Programs / Q000706:statistics & numerical data; D008875:Middle Aged; D009459:Neuroleptic Malignant Syndrome / Q000175:diagnosis* / Q000453:epidemiology*; D012189:Retrospective Studies; D012306:Risk; D014481:United States
D014150:Antipsychotic Agents