Research Activities, February 2014
Clozapine's superior effectiveness relative to other antipsychotic drugs is confirmed
The superior effectiveness of the antipsychotic drug clozapine in the treatment of schizophrenia, demonstrated in clinical trials, is not influenced by the patient's race or ethnicity, according to a new study. In a study of black, Latino, and white Florida residents with schizophrenia insured by Medicaid, of 20,122 persons prescribed an antipsychotic drug, the proportion of blacks and Latinos taking clozapine (2.3 percent and 2.1 percent, respectively) was lower than that of whites (5.9 percent).
Julie M. Donohue, Ph.D., of the University of Pittsburgh's Graduate School of Public Health, Marcela Horvitz-Lennon, of the RAND Corporation, and colleagues compared 749 propensity score-matched sets of clozapine users and users of other antipsychotics. They found that clozapine users, regardless of race or ethnicity, had a 55 percent lower risk of discontinuing their medication. Moroever, the time to discontinuation of antipsychotic medication was longer for clozapine users than users of other antipsychotic drugs, regardless of race or ethnicity (clozapine median days to discontinuation: 1,422 for blacks, 1,659 for Latinos, 1,228 for whites; other antipsychotics median days to discontinuation: 459 for blacks, 566 for Latinos, 639 for whites).
The researchers note that their findings highlight the need for efforts to boost clozapine use, particularly among minority groups. The study was funded in part by AHRQ (HS17695).
More details are in "The effect of race–ethnicity on the comparative effectiveness of clozapine among Medicaid beneficiaries," by Marcela Horvitz-Lennon, M.D., M.P.H., Dr. Donohue, Judith R. Lave, Ph.D., Margarita Alegria, Ph.D., and Sharon-Lise T. Normand, Ph.D., in Psychiatric Services 64(3), pp. 230-237, 2013.