Sentence:  In May 1959 , prednisone , 30 mg. daily , replaced the <WSD>dexamethasone</WSD> . 
Meaning of the word marked with <WSD> tags:  a corticosteroid drug (trade names Decadron or Dexamethasone Intensol or Dexone or Hexadrol or Oradexon) used to treat allergies or inflammation