There are several known polymorphisms in this larger family of opioid receptors that may inform naltrexone pharmacogenetics beyond the A118G SNP of the OPRM1 gene. In fact, a clinical study of naltrexone found trend-level main effect for an OPRK1 marker (rs963549) on relapse rates despite not replicating the A118G SNP effect (Gelernter et al., 2007). Therefore, the goal of the present study was to extend the literature by testing for pharmacogenetic effects of kappa and delta opioid receptor SNPs on subjective responses to alcohol and alcohol craving while controlling for the pharmacogenetic effect of the A118G SNP of the OPRM1 gene. This was accomplished by conducting additional sequencing of tag SNPs (tSNPs) in the OPRD1 and OPRK1 genes and completing a re-analysis of a previously published placebo-controlled laboratory study of naltrexone (Ray and Hutchison, 2007). Given that there are no known functional polymorphisms in the OPRD1 and OPRK1 genes, a tSNP approach was used to provide coverage of the two genes of interest. Consistent with this data-driven approach and with the absence of functional data on these markers, no a-priori
