Suggest Alternate Medicine For Omnacortil

i hav arthritis...doctors say that not RA.....as stated in my prescription it is unifferentiated CID with cutaneous vasculities...i do not really understand it....a doctor suggested me omnacortail-10 mg....due to which i thnk i am gaining weight constantly....can u suggest me ,how can i prevent this constant weight gain...apart from this am having many other mediciens...help!