I would imagine you would be ok? What gauge are you using now? Are you using a light gauge and are concerned that the larger diameter strings won't fit in the nut? I've never heard that being a problem before.
Going FROM Mediums, to Medium lights... I'm just worried about excessive slack, w the string sitting in the groove.
I see, I didn't realize that you said it originally. I really don't think you will have any problems at all. I switch from 40 to 45 and back again occasionally and I see no difference.