title: Risperidone and corrected QT-interval prolongation in surface electrocardiogram.
abstract: Risperidone is an antipsychotic medication suspected of causing QT prolongation and several cases are reported in this regard. However, available information with respect to its effect on QT interval is limited especially from different settings. The aim of this study was to assess the effect of risperidone in lengthening QT interval among psychotic patients referred to a psychiatric ward in North West of Iran. A controlled cohort study was conducted on psychotic patients referred to Razi Hospital from April 2010-2011. The treatment cohort groups were 120 patients receiving risperidone for the first time during their treatment. The comparison cohort included 60 control patients who were not receiving risperidone. An electrocardiogram was obtained from all the study participants at admission time, one week afterwards and at discharge. Corrected QT interval (QTc) was determined using Bazett's formula. QTc dispersion was calculated as Max(QTc)-Min(QTc). Data were analyzed using SPSS statistical software package. The mean change in QTc measures over time was not statistically significant in control group. However, QTc increment was statistically significant over time in V1 and V3 leads in risperidone group. Multivariate longitudinal data analysis, using between-effects model, to manage multiple measurements over time found the overall QTc trend to be different between the groups (p < 0.01). Risperidone may have significant effects on QT interval and QT dispersion. Physicians and psychiatrists should be aware that prolonged QTc interval is a potential indicator of cardiovascular risk and should be cautious in prescribing potentially QT-prolonging medications, at least to certain patients.
authors.affiliation: Clinical Psychiatry Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: F
authors.initials: F
authors.lastname: Ranjbar
authors.forename: F
authors.initials: F
authors.lastname: Akbarzadeh
authors.forename: N M
authors.initials: NM
authors.lastname: Ahmadi
authors.forename: M
authors.initials: M
authors.lastname: Abbasnejhad
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000494:pharmacology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007492:Iran; D008133:Long QT Syndrome / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018967:Risperidone / Q000009:adverse effects / Q000494:pharmacology*
chemical_list: D014150:Antipsychotic Agents; D018967:Risperidone