What Causes Suicidal Thoughts While On Prozac?

Well so my boyfriend has recently been diagnosed with anorexia and depression and has been taking fluoxetine (prozac?) for about a month now. For the last couple of weeks he s been convincing me that the drugs are working and he s feeling better, he also sleeps a lot more than he used to. But last night I was talking to him on the phone (we re long-distance because of uni) and he admitted that his suicidal thoughts have gotten a lot worse and real (I m not sure what he meant by that exactly). I m scared he s lying to me about his disorders (says he doesn t want to worry me ) and also he had an appointment with his psychiatrist last week and he told me he hadn t mentioned the suicidal thoughts to him either. The thing is that as I mentioned we re long distance and he s completely alone in a city far away from all his friends and family. I m extremely worried he might do something bad and wouldn t tell me (or anyone, for that matter). What should I do? Also about the sleeping thing, he says the thoughts get worse at night. Tonight I saw that he was online on Facebook (accidentally, didn t plan to be a stalker) long after he had said he was going to bed but when I asked him in the morning about the night he said it was good and slept throughout the whole night. I don t want to confront him about this but I m scared he might be lying... Is there anything I could/should do?