Instead of performing on stage, Miley Cyrus is lying in a hospital bed.

The singer has been laid up after suffering a severe allergic reaction to antibiotics. That forced her to canceled her Bangerz tour appearance scheduled for Tuesday at the Kansas City Sprint Center.

Miley tweeted, "Kansas I promise I'm as [heartbroken] as you are. I wanted so badly 2 b there 2night. Not being with y'all makes me feel [worse] than I already do."