I agree with the others - drink lots of fluids, take some healthy snacks, and watch the rate at which they are infusing it. If they increase the rate and you start to feel bad - light-headed, headache, whatever - then ask them to slow it down to a rate at which you don't feel those side effects. My personal preference is to take as long as necessary for the infusion to avoid the side effects. Don't be afraid to tell them you aren't feeling good and to please slow it down.

When I do it, they start really slow and bump it up every 30 minutes, essentially doubling it each time. But, I've found that I start to feel bad if we increase it too much at once (like doubling it from 60 to 120), so I get them to go from a rate of 60 to 100 and then to 120. I also rarely go over 120, even though the pharmacy instructions say that it can go up to a rate of 240 or something like that.