I began Famvir 7 months ago. I quickly was able to work up to 2500 mg daily (2x 500mg tabs am & pm+1x 500mg tab at lunch) I haven't been able to tolerate a higher dose than that without horrible headaches and dizziness. I'm treating EBV, HHV-1, HHV-6 and Coxsackie B3. Before Famvir, my viral titres of EBV and HHV-1 were higher than the lab measures and HHV-6 was 1:320. NK cell functional assay was 26. I just got labs back and my viral titres haven't budged and my NK cell functional assay fell to 11. Since receiving this disheartening news, I have added in inositol 500mg twice daily and Equilibrant twice daily over the past few weeks (I started slowly and worked up). I'm scheduled for a followup visit with Dr. Kogelnik at the end of the month and considering switching to Valcyte. I have been very concerned about the Valcyte toxicity and chose Famvir because of it. Fortunately my liver and kidney panels have remained in the normal range throughout the Famvir treatment. I don't have health insurance so I have been paying for generic Famvir out of pocket. I'm so frustrated that I have spent so much time and money and still feel awful.