The Collaborative International Dictionary of English v.0.48:

Impatiently \Im*pa"tient*ly\, adv.
   In an impatient manner.
   [1913 Webster]

WordNet (r) 3.0 (2006):

impatiently
    adv 1: with impatience; in an impatient manner; "he answered her
           impatiently" [ant: patiently]

Moby Thesaurus II by Grady Ward, 1.0:

22 Moby Thesaurus words for "impatiently":
   animatedly, anxiously, avidly, breathlessly, eagerly,
   enthusiastically, fretfully, intolerantly, keenly, promptly,
   quickly, readily, restively, restlessly, uneasily, vivaciously,
   with alacrity, with gusto, with open arms, with relish, with zest,
   zestfully