A Biased View of μ-Opioid Receptors?

Research output: Contribution to journalArticle (Academic Journal)peer-review

73 Citations (Scopus)
2 Downloads (Pure)


The field of biased agonism has grown substantially in recent years and the μ-opioid receptor has been one of the most intensively studied receptor targets for developing biased agonists. Yet, despite extensive research efforts, the development of analgesics with reduced adverse effects remains a significant challenge. In this review we discuss the evidence to support the prevailing hypothesis that a G protein-biased agonist at the μ-opioid receptor would be an effective analgesic without the accompanying adverse effects associated with conventional μ-opioid agonists. We also assess the current status of established and novel μ-opioid-receptor ligands that are proposed to be biased ligands. 

SIGNIFICANCE STATEMENT: The idea that biased agonists at the μ-opioid receptor might provide a therapeutic advantage in terms of producing effective analgesia with fewer adverse effects has driven the design of novel G protein-biased agonists. However, is the desirability of G protein-biased agonists at μ-opioid receptor substantiated by what we know of the physiology and pharmacology of the receptor? Also, do any of the novel biased agonists live up to their initial promise? Here we address these issues by critically examining the evidence that G protein bias really is desirable and also by discussing whether the ligands so far developed are clearly biased in vitro and whether this produces responses in vivo that might be commensurate with such bias.

Original languageEnglish
Pages (from-to)542-549
Number of pages8
JournalMolecular Pharmacology
Issue number5
Early online date30 Sept 2019
Publication statusPublished - 1 Nov 2019


Dive into the research topics of 'A Biased View of μ-Opioid Receptors?'. Together they form a unique fingerprint.

Cite this