Inky, I hope you have a sense of humor. When I read the title of your thread I read Doctors and Viagra. So here I am reading along and the doctor gives you Viagra? For headaches and pain. It took a good 5 seconds for me to see the word vicodin. About peed laughing at myself. As for the rash, yes, usually not serious. I would ask the pharmacist. Put in a call to doc as well. Take care of youself Inky.