I know that you are aware of this paper:
Anton, R.F., Oroszi, G., O'Malley, S.S., Couper, D.J., Swift, R., Pettinati, H.M. &
Goldman, D. An evaluation of μ-opioid receptor (OPRM1) as a predictor of naltrexone
response in the treatment of alcohol dependence: Results from the combined
pharmacotherapies and behavioral interventions for alcohol dependence (COMBINE)
study. Archives of General Psychiatry 65(2):135-144, 2008. PMCID: PMC2666924

My question is do these patients that respond poorly to naltrexone treament (the ones with the Asn40/Asn40 genotype or the "AA" allele) experience the FDE (first drink effect), the endorphin rush while drinking on Naltrexone? Along the same lines, does naltrexone not adequately cover their opioid receptors?