What Causes Chronic Fatigue Post Treatment For COPD?

76 yr old male with mod Copd. Finished 10 days on levofloxon and prednisone and fluticason fluorite and velanterol inhaler continues to be very weak and sleeps much of the time. No endurance . Has been on Prozac and trazolon for years and Celebrex .Don know why he has no energy