My boyfriend has turned into an uncaring a-hole on Provigil/Modafinil

He used to be sweet, empathetic and humble, but since starting Provigil to help him stay awake at work due to a minor sleep disorder, all he talks about is how annoying his coworkers are and how he can’t stand listening to their personal problems and that he’s so much smarter and more productive than they are. This uncaring attitude is affecting our relationship as well. He no longer checks in with me to see how I’m doing. He doesn’t want to listen to any issues I may be dealing with in my life. He talks over me and is definitely not the caring guy I used to know. I’ve suggested that the meds may be affecting his personality in a negative way and he says he doesn’t care, that he needs them to be productive at work (I think he’s taking them on the weekends though too). Is it really safe for him to be taking these meds every day? I’m completely crushed that this change in him is wrecking our relationship and he doesn’t seem to care. Is there anything I can do to get back my sweet boyfriend?