Compounds represented by Formula I: (wherein A, B, D, P, Q, R.sup.1, R.sup.2, R.sup.3, W and Y are described herein) or pharmaceutically acceptable salts thereof, are effective as NMDA/NR2B antagonists useful for treating neurological conditions such as, for example, pain, Parkinson's disease, Alzheimer's disease, epilepsy, depression, anxiety, ischemic brain injury including stroke, and other conditions.