Compounds of Formula I: ##STR00001## and Formula II: ##STR00002## (where variables R.sup.1, R.sup.2, R.sup.3, R.sup.4, A, B, D, G, J, Q, T, W, X and Y are as defined herein) useful as antagonists of CGRP receptors and useful in the treatment or prevention of diseases in which the CGRP is involved, pharmaceutical compositions comprising these compounds, use of these compounds and compositions to prevent or treat diseases involving CGRP.