The reason you shouldn't take it at night it because it can mess up your natural cortisol levels. <a target=_blank class=ftalternatingbarlinklarge href="http://www.skinsite.com/info_prednisone_cortisone_internal.htm">http://www.skinsite.com/info_p...cortisone_internal.htm</a> . I also have trouble sleeping from it at night. So unless your doctor prescribed at night, you should take it in the morning. But if it's a burst I'm not sure it will really do anything in the short term.