Compounds of the invention are useful in inhibiting thrombin and associated thrombotic occlusions having the following structure Formula (I): wherein u is CH or N; Q is 1)--N(R.sup.25)CH(R.sup.30)-- wherein the nitrogen atom is attached to R.sup.1, and R.sup.25 and R.sup.30 are independently selected from the group consisting of hydrogen, C.sub.3-6cycloalkyl, and C.sub.1-6alkyl, or 2) wherein the nitrogen atom is attached to R.sup.1, and m is 0, 1, or 2 ##STR00001##