WordNet (r) 3.0 (2006):

metoprolol
    n 1: beta blocker (trade name Lopressor) used in treating
         hypertension and angina and arrhythmia and acute myocardial
         infarction; has adverse side effects (depression and
         exacerbation of congestive heart failure etc.) [syn:
         metoprolol, Lopressor]