A pharmaceutical composition comprising a therapeutically effective amount of a compound having a structure represented by Formula Ia or Formula Ib for use in a method of treating tinnitus: wherein R 1 is OH or a phosphate containing group; R 3 is hydrogen, halogen, C 1 -C 6 alkyl halide, hydroxyl, C 1 -C 6 hydroxyalkyl, amino, C 1 -C 6 aminoalkyl, cyano, or nitro; R 4 is halogen, C 1 -C 6 alkyl halide, hydroxyl, C 1 -C 6 hydroxyalkyl, amino, C 1 -C 6 aminoalkyl, cyano, or nitro; R 8 is hydrogen, halogen, C 1 -C 6 alkyl halide, hydroxyl, C 1 -C 6 hydroxyalkyl, amino, C 1 -C 6 aminoalkyl, cyano, nitro, or a 5-7 membered heterocyclic moiety; R 2, R 5, R 6, R 7, R 9, and R 10 are, independently, hydrogen, halogen, C 1 -C 6 alkyl halide, hydroxyl, C 1 -C 6 hydroxyalkyl, amino, C 1 -C 6 aminoalkyl, C 1 -C 6 alkoxy, cyano, nitro, C 1 -C 6 alkyl, C 1 -C 6 alkenyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, or heteroaryl ring, or two of R 2, R 3, R 5, R 6, R 7, R 9, and R 10 combine to form a cycloalkenyl, heterocycloalkenyl, aryl, or heteroaryl ring; and ----- is a bond that is optionally present, A is a direct bond or -CH 2 O-; B is a direct bond or oxygen; D is -(CH 2) x - or -CH 2 CHOHCH 2 -, wherein x is an integer from 1 to 4; R is -NR a R b or -NR a R b R c X in which X is a counter anion; and R a, R b, and R c each are independently hydrogen or C 1-4 alkyl; or a nontoxic pharmaceutically acceptable salt or solvate thereof; a pharmaceutically acceptable excipient, wherein the composition provides sustained release of the compound represented by Formula Ia or Ib. R 1 is OH or a phosphate containing group; R 3 is hydrogen, halogen, C 1 -C 6 alkyl halide, hydroxyl, C 1 -C 6 hydroxyalkyl, amino, C 1 -C 6 aminoalkyl, cyano, or nitro; R 4 is halogen, C 1 -C 6 alkyl halide, hydroxyl, C 1 -C 6 hydroxyalkyl, amino, C 1 -C 6 aminoalkyl, cyano, or nitro; R 8 is hydrogen, halogen, C 1 -C 6 alkyl halide, hydroxyl, C 1 -C 6 hydroxyalkyl, amino, C 1 -C 6 aminoalkyl, cyano, nitro, or a 5-7 membered heterocyclic moiety; R 2, R 5, R 6, R 7, R 9, and R 10 are, independently, hydrogen, halogen, C 1 -C 6 alkyl halide, hydroxyl, C 1 -C 6 hydroxyalkyl, amino, C 1 -C 6 aminoalkyl, C 1 -C 6 alkoxy, cyano, nitro, C 1 -C 6 alkyl, C 1 -C 6 alkenyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, or heteroaryl ring, or two of R 2, R 3, R 5, R 6, R 7, R 9, and R 10 combine to form a cycloalkenyl, heterocycloalkenyl, aryl, or heteroaryl ring; and ----- is a bond that is optionally present, A is a direct bond or -CH 2 O-; B is a direct bond or oxygen; D is -(CH 2) x - or -CH 2 CHOHCH 2 -, wherein x is an integer from 1 to 4; R is -NR a R b or -NR a R b R c X in which X is a counter anion; and R a, R b, and R c each are independently hydrogen or C 1-4 alkyl; A is a direct bond or -CH 2 O-; B is a direct bond or oxygen; D is -(CH 2) x - or -CH 2 CHOHCH 2 -, wherein x is an integer from 1 to 4; R is -NR a R b or -NR a R b R c X in which X is a counter anion; and R a, R b, and R c each are independently hydrogen or C 1-4 alkyl; or a nontoxic pharmaceutically acceptable salt or solvate thereof; a pharmaceutically acceptable excipient, wherein the composition provides sustained release of the compound represented by Formula Ia or Ib.