Is Isotretinoin effective for rosacea?

After being on every antibiotic under the sun, my dermatologist has recommended 10/20mg of Isotretinoin twice a week. My problem is that I have tried it before, but only for a week or two; my symptoms worsened: extreme redness and flushing, greasy look, and spots everywhere. My question is, are these just temporary side effects and will the rosacea eventually improve? How long should I wait? I am really getting desperate- nothing else works for me, including lasers. Thanks