Targeting multiple opioid receptors - improved analgesics with reduced side effects?

Area of Science:

• Pharmacology
• Medicinal Chemistry
• Neuroscience

Background:

• Classical opioids like morphine act on the μ-opioid receptor, causing side effects such as constipation and respiratory depression.
• Opioid receptor family includes μ, κ, δ, and nociceptin/orphanin FQ peptide (NOP) receptors, each contributing to analgesia and side effects.
• Developing novel analgesics that target multiple opioid receptors simultaneously offers a strategy to improve efficacy and reduce adverse events.

Purpose of the Study:

• To review the paradigm of single chemical entities designed to target multiple opioid receptors.
• To discuss the biological actions of multi-opioid receptor ligands.
• To explore the potential of multi-target opioid ligands in pain management.

Main Methods:

• Literature review of recent research on multi-opioid receptor ligands.
• Analysis of the biological actions of specific multi-target compounds.
• Discussion of the rationale behind developing single molecules that interact with multiple opioid receptors.

Main Results:

• Several novel multi-opioid receptor ligands are under investigation, including bifunctional μ/NOP receptor agonists (e.g., cebranopadol, SR16835, SR14150).
• Ornivol BU08028, an analogue of buprenorphine, and nalfurafine, a κ receptor-focused ligand used for pruritus, represent different multi-target approaches.
• Dihydroetorphine is a potent ligand acting on μ, κ, and δ receptors, exemplifying a true multi-receptor opioid ligand.

Conclusions:

• Multi-opioid receptor ligands represent a promising new generation of analgesics.
• Targeting multiple opioid receptors with a single molecule may lead to improved analgesic effects and a better side effect profile.
• Further research into the biological actions of these ligands is crucial for their clinical development.