Antagonists of cholecystokinin-B (CCK-B) receptors have been shown to alleviate CC&- induced panic attacks in humans and to potentiate opioid effects in animals. The clinical use of these compounds is critically dependent on their ability to cross the blood-brain barrier. In order to improve this property, new, peptoid-derived CCK-B antagonists, endowed with high affinity, selectivity, and increased lipophilicity have been developed. The affinity and ...