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Comparison of the Effects of OPRM1 A118G Polymorphism Using Different Opioids: A Prospective Study

Miho Takemura1, Kazuyuki Niki1, Yoshiaki Okamoto2

  • 1Department of Clinical Pharmacy Research and Education (M.T., K.N., K.I.), Osaka University Graduate School of Pharmaceutical Sciences, Suita, Osaka, Japan; Department of Pharmacy (M.T., K.N., Y.O.), Ashiya Municipal Hospital, Ashiya, Hyogo, Japan.

Journal of Pain and Symptom Management
|September 27, 2023
PubMed
Abstract

Insights

The OPRM1 A118G polymorphism affects opioid efficacy. Tapentadol and methadone are more effective for G-allele carriers compared to hydromorphone, oxycodone, and fentanyl.

Area of Science:

  • Pharmacogenomics
  • Pain Management
  • Genetics

Background:

  • The μ-opioid receptor gene (OPRM1) A118G polymorphism (rs1799971) impacts μ-opioid receptor glycosylation.
  • G-allele carriers exhibit reduced response to morphine, but data on other opioids are limited.

Purpose of the Study:

  • To investigate the influence of the OPRM1 A118G polymorphism on the efficacy of various opioid analgesics in cancer pain management.

Main Methods:

  • A prospective cohort study included 222 cancer patients receiving tapentadol, methadone, hydromorphone, oxycodone, or transdermal fentanyl.
  • The change in Brief Pain Inventory-Short Form scores from baseline at days 3, 7, and 14 was compared across genotypes and opioid treatments.

Main Results:

  • No significant difference in pain score reduction was observed for tapentadol or methadone across OPRM1 A118G genotypes.
  • G-allele carriers showed significantly smaller pain reduction with hydromorphone, oxycodone, and fentanyl compared to AA homozygous patients.

Conclusions:

  • Tapentadol and methadone appear more suitable for G-allele carriers due to their dual mechanisms and lower susceptibility to OPRM1 A118G polymorphism effects.
  • Hydromorphone, oxycodone, and fentanyl efficacy may be compromised in G-allele carriers.
Keywords:
A118G polymorphismcancer painopioid receptor mu 1opioidspersonalized medicinepharmacogenetics

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