Pharmacogenetics of Naltrexone for Stimulant Abuse

A recent meta-analysis concluded that the OPRM1 A118G SNP (rs1799971) significantly moderates the treatment efficacy of Naltrexone (NTX) in treating alcohol abuse, increasing the treatment efficacy by over 2-fold among G-allele carriers (AG/GG). The proposed application would be the first to investigate the moderating effect of this genotype in the efficacy of NTX to treat stimulant abuse. More specifically, the study team proposes to investigate the interaction between NTX and intranasal (IN) methamphetamine (30mg/70kg). Participants who meet DSM criteria for mild-to-severe stimulant use disorder (N=up to 70) will complete 4 testing sessions where drug effects are tested following pretreatment with NTX (0, 50 mg). Naltrexone pretreatment effects upon the abuse liability of IN methamphetamine will be assessed using self-report measurements of positive subjective effects and drug self-administration. Medication effects on these validated predictors of abuse potential will be compared between A118G A allele homozygotes (AA) and G-allele carriers (AG/GG; an anticipated 25% of the total sample), in order to assess genetic moderation of treatment outcome.