Started Valtrex last Thurs and all of a sudden today, I am having similar symptoms as on acyclovir. It's crazy. My EBV is very high and HHV6 is also. Tonight, I feel like I have stabbing pains in my feet. Everything hurts. Muscles are twitching like crazy. Is this common with antivirals? I am determined to stick it out because my doctor said that it helped another patient with her intercostal neuralgia which has been out of control for me. I've been sick for 25 years and I'm pretty sure that my Epstein-Barr virus is still the biggest culprit. That's what started this whole thing-the Epstein-Barr virus. I am only taking 500 mg once a day. That's not a lot! Could someone give me some tips or help me out with if this is a common side effect, or symptom, or die off? My main side effect is pain. This is definitely not for a sissy!