Doxycycline
"I got bitten by a tick while training for a 100 miler endurance race. I developed the bulls eye textbook version of the rash within a week of the bite. I was placed on Doxy immediately. The first week was tough. It was hard getting out of bed since I felt very exhausted; I gained a whole lot of weight. After a month of taking Doxy, I started 'feeling better'. I have energy and although running is harder than ever, I am doing a lot more than when I first begin this medication. One thing I have battled is yeast infections throughout this month. I have one more month to go and I will update this thread."