Racial differences in medication switching and concomitant prescriptions in the treatment of bipolar disorder.
OBJECTIVE
This study examined whether the practices of switching between classes of medications and prescription of concomitant medications differed between black and non-black patients with bipolar disorders.


METHODS
In a retrospective cohort design, data from 1998 to 2004 for patients with diagnoses of bipolar disorders were obtained from a large claims database. Information was obtained on the number of prescriptions for four classes of medications (anticonvulsants, mood stabilizers, and first- and second-generation antipsychotics) as well as on medication switching (between drug classes), concomitant prescriptions, resource use, and outcomes (an emergency department visit or a hospitalization). Logistic models assessed the relationship between outcomes and switching or concomitant prescriptions.


RESULTS
The study population consisted of 1,113 adults who received at least one prescription from the four drug classes. Medication switching or concomitant prescriptions were documented for more than one-third of patients (36.6 percent). A significantly greater proportion of black patients received two or more medications from different drug classes (41.1 compared with 34.7 percent). The number of prescriptions was lower for black patients than for non-black patients. Patients for whom switching or concomitant prescriptions were documented were significantly more likely to have an emergency department visit or a hospitalization, and race was a significant predictor of these outcomes.


CONCLUSIONS
The prevalence of polypharmacy-medication switching and concomitant prescriptions-was high among patients with bipolar disorder, with a higher prevalence among black patients. Patients who experienced switching or concomitant prescriptions were more likely to visit the emergency department or to be hospitalized.
Garver
David
D
University of Louisville in Kentucky450 Park Ave South, 12th Floor, New York, New York 10016, USA. lkatz@analyticaintl.com
Lazarus
Arthur
A
Rajagopalan
Kitty
K
Lamerato
Lois
L
Katz
Laura M
LM
Stern
Lee S
LS
Dolgitser
Margarita
M
Doyle
John J
JJ