The clinical management of severe pain depends heavily on opioids acting through mu opioid receptors encoded by the Oprm1 gene, which undergoes extensive alternative splicing. In addition to generating a series of prototypic seven transmembrane domain (7TM) G protein-coupled receptors (GPCRs), Oprm1 also produces a set of truncated splice variants containing only six transmembrane domains (6TM)...

BACKGROUND It is well known that naltrexone, an FDA-approved medication for treatment of alcohol dependence, is effective for only a subset of individuals. Recent studies have examined the utility of a functional A118G single nucleotide polymorphism (SNP) of the mu-opioid receptor gene (OPRM1) as a predictor of naltrexone treatment response. Although the findings to date have generally been con...

Human mu opioid receptor gene polymorphisms and vulnerability to substance abuse. Sequence variations in the mu-opioid receptor gene (OPRM1) associated with human addiction to heroin. Sequence variability and candidate gene analysis in complex disease: association of mu opioid receptor gene variation with substance dependence. Mu opioid receptor gene variants: lack of association with alcohol d...

Opioid receptors and their endogenous peptide ligands play important roles in neurotransmission and neuromodulation in response to addictive drugs such as heroin, cocaine, and alcohol. In an earlier study, we reported that variation in the genes encoding the kappa-opioid receptor (OPRK1) and its peptide ligand (PDYN) were associated with the risk for alcoholism. We continued our investigation o...

Use of prescription opioids for cancer pain according to the World Health Organization analgesic ladder has been accepted in Japan. Although oxycodone and fentanyl are commonly used as first-line analgesics, a few clinical reports have been published on interindividual variations in their pharmacokinetics and clinical responses in cancer patients. (1) Some factors relating to CYP2D6, CYP3A, ATP...

Objective: Cytochrome P450 2B6 (CYP2B6) is involved in the metabolism of several therapeutically important drugs and abused intoxicants including methadone. The preferential binding target for methadone is the μ opioid receptor OPRM1. Various SNPs in CYP2B6 and OPRM1 may contribute to clinical outcomes in methadone maintenance therapy. The aim of the present study was to develop a consistent an...

BACKGROUND Research suggests that the COMT Val(158)Met, BDNF Val(66)Met and OPRM1 A(118)G polymorphisms moderate the experience of pain. In order to obtain experimental confirmation and extension of findings, cortical processing of experimentally-induced pain was used. METHOD A sample of 78 individuals with chronic low back pain complaints and 37 healthy controls underwent EEG registration. E...

Opioids, such as morphine, fentanyl and oxycodone, are important to treat cancer pain. Opioids also associated with adverse effects respiratory depression, constipation, nausea sedation. There significant variations between individuals in analgesic effects. Mechanisms underlying differences incompletely understood, likely multifactorial, include genetic environmental contributions. Ma...