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ABSTRACT: Background
In an initial study, we reported that topiramate reduced heavy drinking among individuals who sought to reduce their drinking and that the effect was moderated by a single nucleotide polymorphism (SNP; rs2832407) in GRIK1, which encodes the kainate GluK1 receptor subunit (Kranzler et al., 2014). In a subsequent study that prospectively randomized patients to medication group based on their rs2832407 genotype, we replicated the main effect of topiramate but not the moderating effect of the SNP (Kranzler et al., 2021). Given the similar design of the two studies, here we combined the findings to provide greater statistical power to test the pharmacogenetic effect.Material and methods
This secondary analysis of two 12-week, randomized controlled trials of topiramate included a total of 292 European-ancestry individuals (67.1 % male; topiramate: 48.3 %, placebo: 51.7 %) with problematic alcohol use. Using MANOVA, we examined changes in self-reported alcohol consumption, problems resulting from alcohol use, and quality of life, and the biomarker γ-glutamyltransferase. To test the pharmacogenetic hypothesis, all patients were genotyped for rs2832407.Results
There was a significant overall effect of topiramate on the alcohol-related outcomes (partial η2 = 0.134, p < 0.001), with follow-up analyses showing significant reductions in percent heavy drinking days (Cohen's d = 0.49), percent days abstinent (d = 0.23), drinks/day (d = 0.29) and alcohol-related problems (d = 0.45). Overall, the moderating effect of the SNP was non-significant (partial η² = 0.026, p = 0.37).Conclusions
Although topiramate is an efficacious medication for reducing drinking and alcohol-related problems among patients with problematic alcohol use, rs2832407 does not appear to moderate its therapeutic effects. www.clinicaltrials.gov registrations: NCT00626925 and NCT02371889.
SUBMITTER: Kranzler HR
PROVIDER: S-EPMC8282735 | biostudies-literature | 2021 Aug
REPOSITORIES: biostudies-literature
Kranzler Henry R HR Hartwell Emily E EE Feinn Richard R Pond Timothy T Witkiewitz Katie K Gelernter Joel J Crist Richard C RC
Drug and alcohol dependence 20210521
<h4>Background</h4>In an initial study, we reported that topiramate reduced heavy drinking among individuals who sought to reduce their drinking and that the effect was moderated by a single nucleotide polymorphism (SNP; rs2832407) in GRIK1, which encodes the kainate GluK1 receptor subunit (Kranzler et al., 2014). In a subsequent study that prospectively randomized patients to medication group based on their rs2832407 genotype, we replicated the main effect of topiramate but not the moderating e ...[more]