Alvimopan (S5935-GRP)

Alvimopan (LY 246736, ADL 8-2698) is a potent, relatively nonselective opioid antagonist with Ki values of 0.77, 4.4, and 40 nM for the μ, δ, and κ opioid receptors, respectively, displaying >100-fold selectivity over other aminergic G-protein-coupled receptors.