Sentence:  In May 1959 , <WSD>prednisone</WSD> , 30 mg. daily , replaced the dexamethasone . 
Meaning of the word marked with <WSD> tags:  a dehydrogenated analogue of cortisol (trade names Orasone or Deltasone or Liquid Pred or Meticorten); used as an anti-inflammatory drug in the treatment of arthritis and as an immunosuppressant