A compound of the following formula: wherein: X is a residue of a ketone-containing opioid, wherein the hydrogen atom of the corresponding hydroxyl group of the enolic tautomer of the ketone is replaced by a covalent bond to -C -N[(A ring)-Y c]-(CR 1 R 2) a -NH-C -CH(R 5)-N(R 3)-[C -CH(R 6)-N(R 3)] b -R 7; the A ring is a heterocyclic 5 to 12-membered ring; each Y is independently selected from alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, and cyano; c is a number from zero to 3; each R 1 is independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, and cyano; each R 2 is independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, and cyano; or R 1 and R 2 together with the carbon to which they are attached can form a cycloalkyl or substituted cycloalkyl group, or two R 1 or R 2 groups on adjacent carbon atoms, together with the carbon atoms to which they are attached, can form a cycloalkyl or substituted cycloalkyl group; a is an integer from one to 8; provided that when a is one, the A ring is a heterocyclic 6 to 12-membered ring; and when the A ring is a heterocyclic 5-membered ring, then a is an integer from 2 to 8; each R 3 is independently hydrogen, alkyl, substituted alkyl, aryl or substituted aryl; R 5 is selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl, and substituted heteroarylalkyl; each R 6 is independently selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl, and substituted heteroarylalkyl; b is a number from zero to 100; and R 7 is selected from hydrogen, alkyl, substituted alkyl, acyl, substituted acyl, alkoxycarbonyl, substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl; or a salt, hydrate or solvate thereof. X is a residue of a ketone-containing opioid, wherein the hydrogen atom of the corresponding hydroxyl group of the enolic tautomer of the ketone is replaced by a covalent bond to -C -N[(A ring)-Y c]-(CR 1 R 2) a -NH-C -CH(R 5)-N(R 3)-[C -CH(R 6)-N(R 3)] b -R 7; the A ring is a heterocyclic 5 to 12-membered ring; each Y is independently selected from alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, and cyano; c is a number from zero to 3; each R 1 is independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, and cyano; each R 2 is independently selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, acyl, substituted acyl, carboxyl, alkoxycarbonyl, substituted alkoxycarbonyl, aminoacyl, substituted aminoacyl, amino, substituted amino, acylamino, substituted acylamino, and cyano; or R 1 and R 2 together with the carbon to which they are attached can form a cycloalkyl or substituted cycloalkyl group, or two R 1 or R 2 groups on adjacent carbon atoms, together with the carbon atoms to which they are attached, can form a cycloalkyl or substituted cycloalkyl group; a is an integer from one to 8; provided that when a is one, the A ring is a heterocyclic 6 to 12-membered ring; and when the A ring is a heterocyclic 5-membered ring, then a is an integer from 2 to 8; each R 3 is independently hydrogen, alkyl, substituted alkyl, aryl or substituted aryl; R 5 is selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl, and substituted heteroarylalkyl; each R 6 is independently selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, heteroalkyl, substituted heteroalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl, and substituted heteroarylalkyl; b is a number from zero to 100; and R 7 is selected from hydrogen, alkyl, substituted alkyl, acyl, substituted acyl, alkoxycarbonyl, substituted alkoxycarbonyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl; or a salt, hydrate or solvate thereof.