Person (65 years old) suffers from sever cough and difficult in breath . doctors said its pulmonary fibrosis? please what's drug or treatment to him?

Depends on the cause: There is no good treatment to reverse pulmonary fibrosis but the progression may be thwarted if one knows the trigger mechanism. I presume that this person is under the care of a board certified pulmonologist who may prescribe oxygen for the condition.

Very little: There is no therapy for pulmonary fibrosis. Symptomatic relief may be helped with oxygen , Imuran (azathioprine) and possible steroids, progressive dis may be treated with lung transplant.