@Treeman, I believe that you are mixing up Valtrex and Valcyte. It has been 12 years, but as I remember the dosage for Valcyte patients is 450 mg twice a day. Dr. Lerner used both drugs as conditions warranted.
Valcyte is a very expensive drug, Walmart will sell you a months worth, 60 tablets, for $ 1,432.31. This is much less expensive than it was when I took it, and it should be used only with a doctors supervision, as regular blood tests should be a part of your usage.
Valtrex is much less expensive and could probably be used without a doctors supervision. There are several other antivirals that could possibly help, more information is available at
https://hhv-6foundation.org/category/antiviral-treatments.
The decision on which drug to take should involve testing to determine which viruses are present. The testing is very controversial and all testing labs are not created equal.
When I started on Valcyte it was a relatively new drug. I attended the HHV-6 conference in Baltimore in 2008 and met Dr. Montoya's wife. We got to talking and she said that she was wheelchair bound before she started taking Valcyte. At the conference she was very active and didn't seem visibly impaired. Valcyte has definitely worked for some.
Please understand that I have no medical training and am just going by my experience. Finding a doctor that understands the use of antivirals to treat ME/CFS can be a very difficult task. I went to the Mayo Clinic in Rochester, MN in the hopes of finding a knowledgeable doctor. They are very good at finding out what is not wrong with you, which is how they diagnose ME/CFS, if they can't find anything else, then you have ME/CFS. After many trips I began doing my own research and found enough information to convince the doctor to prescribe Valcyte. It took me 25 trips to finalize things there. I was able to convince him to let me use the drug for 10 months. At the time, I had no idea of how long a person should take it, as there wasn't much in the way of experience with the drug and ME/CFS. There is a lot more information on the HHV-6 website today than there was 12 years ago. Today I would stay on the drug for as long as possible, or as long as the insurance company would keep paying for it.