I have just started on sulphasalazine a couple of weeks ago, and since then I have had a couple of instants of dizziness. I was told one of the side effects was a feeling of light headedness but this feels like a sugar low (or what I imagine one would feel like). I did eat some chocolate afterwards and started to feel OK.
the only thing I remember when I started sulfasalazine was bad headaches, which went away after drinking more water. Hope it doesn't last too long for you.