i did reuse them, however my car had like 3000 miles when i put them on, i'm now over 40k and the could use replaced. I tightened them down with a quick trigger pull of an impact.
If its on the passenger side, and you went "really" low like i know is possible, your axle might be hitting the frame rail, or the tie rod end is hitting, or you might need to adjust the sway bar endlink to clear the swaybar from those items as well.