I started taking Macrobid (Nitrofurantoin Mono-MCR) 100 mg Friday, March 3. I took 2 doses on Friday. Saturday morning I awoke with a severly sore tendon in my neck, back, and right shoulder. It is not gotten better despite two visits to the chiropractor this week, hot tub, ibuprofen, rest, etc. I have two doses left to take. Could it be the Macrobid that has caused this pain? Should I take the last two doses? I m in a lot of pain, and never has my neck/back been out or hurt like this. I have done nothing otherwise to injure myself. I m on the meds for a UTI.