I Took One Bactria DS Around 1:30pm Today , After

I took one Bactria DS around 1:30pm today , after a bladder test ,and now the bottom of my right foot is itchy and swollen and red. The last time I took this the same thing happened in the same place same way. After the swelling goes down then the foot pills off the very spot that blisters up about the size of a fifty scent piece. What can I do and is this a side effect?