Disclosed is a synthetic peptide amide having the formula: Xaa1-Xaa2-Xaa3-(Xaa4)p-G or a pharmaceutically acceptable salt, hydrate, solvate, acid salt hydrate, N-oxide or isomorphic crystalline form thereof wherein: each Xaa1 is independently selected from the group consisting of (A)(A')D-Phe, (á-Me)D-Phe, D-Tyr, D-Tic, D-phenylglycine, D-neopentylglycine, D-phenylglycine, D-homophenylalanine, and â-(E)D-Ala, wherein each (A) and each (A') are phenyl ring substituents independently selected from the group consisting of-H, -F, -Cl, -NO2, -CH3, -CF3, -CN, -CONH2, and wherein each (E) is independently selected from the group consisting of cyclobutyl, cyclopentyl, cyclohexyl, pyridyl, thienyl and thiazolyl； each Xaa2 is independently selected from the group consisting of (A)(A')D-Phe, (á-Me)D-Phe, D-1Nal, D-2Nal, D-Tyr, (E)D-Ala, and D-Tip； each Xaa3 is independently selected from the group consisting of D-Nle, D-Phe, cyclopentyl-D-Ala, D-Leu, (á-Me)D-Leu, D-Hle, D-Val, and D-Met； each Xaa4 is independently selected from the group consisting of (B)2D-Arg, (B)2D-nArg, (B)2D-Har, æ-(B)D-Hlys, D-Dap, ?-(B)D-Lys, ?-(B)2-D-Lys, D-Amf, amidino- D-Amf, ã-(B)2D-Dbu, ä-(B)2á-(B)D-Oni, D-2-amino-3(4-piperidyl)propionic acid, D-2-amino-3(2-aminopyrrolidyl)propionic acid, D-á-amino-amidino-propionic acid, á -amino-4-piperidineacetic acid, cis- á,4-diaminocyclohexane acetic acid, trans- á,4-diaminocyclohexaneacetic acid, cis- á-amino-4-methyl-aminocyclo-hexane acetic acid, trans-a-amino-4-methylaminocyclohexane acetic acid, á -amino-l-amidino-4-piperidineacetic acid, cis-á-amino-4-guanidino-cyclohexane acetic acid, and trans-a-amino-4-guanidinocyclohexane acetic acid, wherein each (B) is independently selected from the group consisting of -H and C1-C4 alkyl, and (B') is -H or (á-Me), and p is zero or 1； and G is as defined in the specification.
