kelatorphan

Kelatorphan is a potent, broad-spectrum inhibitor of enkephalin-degrading enzymes, including neutral endopeptidase (NEP), dipeptidyl peptidase III (DPP3), aminopeptidase N (APN), and angiotensin-converting enzyme (ACE)[1][4][6]. By inhibiting these enzymes, kelatorphan prevents the breakdown of endogenous enkephalins—neuropeptides involved in pain modulation—thereby potentiating their analgesic effects. In animal studies, intracerebroventricular administration of kelatorphan dramatically increased the analgesic potency of exogenous [Met]enkephalin by up to 50,000 times[1][4]. Kelatorphan itself also exhibits strong antinociceptive properties without causing respiratory depression; at high doses it may even increase respiration[1]. Due to its inability to cross the blood-brain barrier, central administration is required for efficacy in preclinical models[1]. Kelatorphan has been primarily used as a research tool and does not have an assigned ATC code or known clinical development status.

Other names

[(R)-3-(N-hydroxy)-carboxamido-2-benzylpropanoyl]-L-alanine