Suggest Treatment For Red Rashes On Buttocks

Hi: I had an angioplasty on Tuesday and today (Sat.) I developed a red and bumpy rash on each buttock (on the round part, not the crack or private parts). I don't know if it is a result of my low or fluctuating blood pressure or if it might be a side effect from my new medications (Plavix, norvasc, benicar, coreg, simvastatin). Thanks for any help you can offer.