The present invention relates to new CGRP-antagonists of general formula I wherein U, V, X, Y, R1, R2, R3 and R4 are defined as in the description, the tautomers, the isomers, the diastereomers, the enantiomers, the hydrates, the mixtures thereof and the salts thereof and the hydrates of the salts, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, medicaments containing these compounds, their use and processes for preparing them.