Shalane,
I would strongly recommend that you speak with your doctor about this matter. Although I doubt that vitamin B12 and multivitamins (that do not contain vitamin A) will have any contradictions with taking
Accutane, the appetite suppressants may, depending on what they are. Your doctor would be the only one who can answer this question for you and give you advice that is safe. But when you do call your doctor and find out the answers please let me know because I am curious myself about this.