title: QTc prolongation and antipsychotic medications in a sample of 1017 patients with schizophrenia.
abstract: Many antipsychotic drugs cause QT prolongation, although the effect differs based on the particular drug. We sought to determine the potential for antipsychotic drugs to prolong the QTc interval (>470 ms in men and >480 ms in women) using the Bazett formula in a "real-world" setting by analyzing the electrocardiograms of 1017 patients suffering from schizophrenia. Using logistic regression analysis to calculate the adjusted relative risk (RR), we found that chlorpromazine (RR for 100 mg=1.37, 95% confidence interval (CI)=1.14 to 1.64; p<.005), intravenous haloperidol (RR for 2 mg=1.29, 95% CI=1.18 to 1.43; p<.001), and sultopride (RR for 200 mg=1.45, 95% CI=1.28 to 1.63; p<.001) were associated with an increased risk of QTc prolongation. Levomepromazine also significantly lengthened the QTc interval. The second-generation antipsychotic drugs (i.e., olanzapine, quetiapine, risperidone, and zotepine), mood stabilizers, benzodiazepines, and antiparkinsonian drugs did not prolong the QTc interval. Our results suggest that second-generation antipsychotic drugs are generally less likely than first-generation antipsychotic drugs to produce QTc interval prolongation, which may be of use in clinical decision making concerning the choice of antipsychotic medication.
authors.affiliation: Department of Psychiatry, Dokkyo University School of Medicine, 880 Kitakobayashi, Mibu, 321-0293, Japan. ozeki@dokkyomed.ac.jp
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ozeki
authors.forename: Kumiko
authors.initials: K
authors.lastname: Fujii
authors.forename: Naoki
authors.initials: N
authors.lastname: Kurimoto
authors.forename: Naoto
authors.initials: N
authors.lastname: Yamada
authors.forename: Masako
authors.initials: M
authors.lastname: Okawa
authors.forename: Takesuke
authors.initials: T
authors.lastname: Aoki
authors.forename: Jun
authors.initials: J
authors.lastname: Takahashi
authors.forename: Nobuya
authors.initials: N
authors.lastname: Ishida
authors.forename: Minoru
authors.initials: M
authors.lastname: Horie
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kunugi
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D016001:Confidence Intervals; D004562:Electrocardiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008133:Long QT Syndrome / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012559:Schizophrenia / Q000188:drug therapy*
chemical_list: D014150:Antipsychotic Agents