Clindamycin
"This has worked great on my MRSA but the side effects have been HORRIBLE.  I have felt like I've had the flu but worse, fever, nauseous, but the worst has been the itching! I'm not breaking out in hives but it's a deep internal itch that I can't stop!  Benadryl helps but makes me sleepy!  I'm not sure if it's an allergic reaction but in all the reviews I have read, no one mentions this."