Initial evidence suggests that a five-marker genotype panel can effectively predict which patients will have a more favorable treatment response with an experimental drug for alcohol addiction, according to a study published in theAmerican Journal of Psychiatry. While additional validation is needed, the authors say that the identification of these genetic variants represents a step forward toward personalized pharmacogenomic treatment of addiction. The researchers had previously identified that the SLC6A4-LL/TT genotypes in the 5-HTT serotonin transporter gene predicted a significantly greater effectiveness of the experimental drug ondansetron. Without patient stratification by genotype, there was no difference between treatment effect in the ondansetron and placebo groups. Since the drug works by blocking certain serotonin receptors (as opposed to binding with the transporter molecules regulated by the 5-HTT gene), the scientists speculated that additional genetic variations affecting the binding receptor might further determine the effectiveness of ondansetron. In the current study, genotyping was performed on one rare and 18 common single-nucleotide polymorphisms in HTR3A, HTR3B, and SLC6A4 genes utilizing samples from the same cohort previously studied. The 283 patients were participating in a randomized, double-blind, 11-week clinical trial in which they received oral ondansetron or placebo along with weekly counseling. The researchers […]