Disclosed are compounds of Formula I, or salts or prodrugs thereof, complexed with a human urotensin II receptor as defined herein. Also disclosed are compounds of Formula II, or salts or prodrugs thereof, as defined herein. Also disclosed are methods of modulating the activity of a urotensin II receptor using a compound of Formula I, or a compound of Formula II, or salts or prodrugs thereof. In addition, methods of treating diseases related to the activity of urotensin II receptors are disclosed.