Naltriben

Naltriben is a potent and selective antagonist for the delta opioid receptor, which is used in scientific research. It has similar effects to the more widely used δ antagonist naltrindole, but with different binding affinity for the δ₁ and δ₂ subtypes, which makes it useful for distinguishing the subtype selectivity of drugs acting at the δ receptors. It also acts as a κ-opioid agonist at high doses.