Yes, and tried both many times. Simple answer: They didn't work. Trust me, I've tried a couple dozen different medications and supplements over the years. Valcyte is the ONLY drug that consistently works for me. Hopefully Letermovir will change that fact.
That's very useful to know.
Regarding a trial of letermovir: it's possible substituting letermovir for Valcyte for might not do the job, if it is the immunomodulatory properties of Valcyte that result in the ME/CFS benefits.
As you may know, as well as being antiviral, Valcyte also has immunomodulatory effects. In Montoya's Valcyte studies, he states that he cannot be sure it is the antiviral action of Valcyte that led to improvements in ME/CFS, because Valcyte also have immunomodulatory properties. So Valcyte might also fight viruses by its immunomodulatory mechanism; or Valcyte's immunomodulation properties may help ME/CFS in way unconnected to viral infection, by altering immune function.
I guess the only way to know for sure if letermovir can substitute for Valcyte is by trying it.
The Supplement Genistein as Potent as Valcyte for Cytomegalovirus
By the way, I may have found a supplement,
genistein, that in very high doses appears to have equal antiviral potency to Valcyte, at least by my calculations (as surprising as that may seem).
I spent several months doing some pharmacokinetic analysis of various compounds (supplements or off-label drugs) with in vitro antiviral effects, to see if I could find compounds with useful antiviral effects in vivo. Most supplements turned out to be very poor antivirals in vivo, even if they have good in vitro antiviral effects. But genistein was an exception, with potent in vivo effect.
I calculated that the genistein in very high doses of around 12 grams daily has about the same in vivo antiviral potency for cytomegalovirus as 900 mg of Valcyte. The downside is that 12 grams of the supplement genistein will cost you around $20, which is actually more expensive than Valcyte, at least the generic Indian version of Valcyte, which costs $7 for 450 mg.
It is possible high dose genistein may be less toxic than Valcyte, although this is debatable:
one study gave 22 people around 12 grams of genistein daily for up to 24 months; over these two years there were several serious adverse events reported, as well as lots of less serious adverse events, which may or may not have been linked to the high dose genistein. You can read the full study on
Sci Hub.
But of course you do not have to use such a very high 12 gram daily dose, you could try something lower like say 1 or 2 grams a day, and that should lessen the risk of adverse effects.
One advantage of genistein is that its antiviral mechanism for cytomegalovirus looks promising from the point of view of curtailing abortive cytomegalovirus infection: genistein appears to work by preventing early and late cytomegalovirus gene expression (see the study
here), which means genistein will prevent CMV from making many of its proteins inside the cell, and this may be able to directly target any ongoing abortive cytomegalovirus infections in ME/CFS patients, reducing the viral proteins made by these abortive infections.
I have not put this pharmacokinetic info on the forum yet, as I am still double checking my figures. I have no background in biology, medicine or pharmacokinetics, so my calculations could easily be wrong, or my methods could be wrong, especially because it is hard to do maths when you have brain fog.
But I am going to be trying genistein myself, perhaps at 1 or 2 grams a day (2 grams of genistein will cost around $3 per day).
Just to give you some figures that I calculated for the in vivo potency:
- Valcyte 900 mg daily for CMV: Antiviral Potency Factor = 4,410
- Genistein 12,000 mg daily for CMV: Antiviral Potency Factor = 4,575
- Genistein 4,000 mg daily for CMV: Antiviral Potency Factor = 1,525
- Genistein 2,000 mg daily for CMV: Antiviral Potency Factor = 763
Note that even at a dose of 1 or 2 grams daily, given that genistein may more directly target abortive cytomegalovirus infections, even such lower doses might be effective for targeting the infections in ME/CFS.
In other words, even though 2 grams of genistein only has an antiviral Potency Factor of 763, compared to 4,500 for 900 mg of Valcyte, if genistein can directly target the abortive infections, that direct attack may well make up for its weaker antiviral effect at 2 grams.