A side effect of the magnesium is that it ups your blood sugar so now Nikki's on insulin too. In addition to the magnesium, insulin, and steroids, they're also giving Elena (through Nikki) penicillin because of the UTI that Nikki had a couple of weeks ago. It's a precaution just in case she does go into labor because as Nikki said it can be dangerous if she passes it along to Elena during labor.
Just talked to Nikki a little while ago, and aside from being totally bored from having to lay flat on her side with not-so-much interest in TV and having a hard time finding a comfortable position for reading, she sounds like she's handling the situation much better than I would be able to. She's on true bed rest... none of that "just sit still" crap. She's flat on her side with strict orders not to move. She's very groggy from the magnesium, but fortunately, everything seems to be doing it's job since the contractions are practically gone.
Nik will definitely be in the hospital for at least 48 hours so that they can monitor everything and continue to give her the necessary medications. Keep Nikki, Elena, Halle, and Mr. Mom Jason in your thoughts and prayers!