Evaluation of G protein bias and β-arrestin 2 signaling in opioid-induced respiratory depression

Respiratory depression is a potentially fatal side effect of opioid analgesics and a major limitation to their use. G protein-biased opioid agonists have been proposed as safer analgesics with less respiratory depression. These agonists are biased to activate G proteins rather than beta-arrestin signaling. Respiratory depression has been shown to correlate with both G protein bias and intrinsic efficacy, and recent work has refuted the role of beta-arrestin signaling in opioid-induced respiratory depression. In addition, there is substantial evidence that G proteins do, in fact, mediate respiratory depression by actions in respiratory-controlling brainstem neurons. Based on these studies, we provide the perspective that protection from respiratory depression displayed by newly developed G protein-biased agonists is due to factors other than G protein versus arrestin bias.

Automated summary

G protein-biased opioid agonists are proposed as safer analgesics with less respiratory depression. Studies have linked respiratory depression to G protein bias and intrinsic efficacy, refuting the role of beta-arrestin signaling in opioid-induced respiratory depression.