Hi Julie.... When my daughter was 3, her presciption was accidentally changed by the pharmacy and we were given cortisone acetate instead of the cortef. We were still new to all this stuff, so we did not notice the switch at first. After three days of taking the cortisone acetate, my daughter became very weepy and irritable. I knew something was wrong and began checking the meds. The original pharmacist said the slight variation would not make a difference. On further investigation, another pharmacist did a bit more research and we were given another presciption for cortef (hydrocortisone). Within a day, my daughter was herself again. Apparently the cortisone acetate is absorbed in the body slightly differently. I know some people take the cortisone acetate with success, but obviously others don't.