Antivirals as ME/CFS or Long Covid treatments (e.g. valacyclovir, valgancyclovir, amantadine)

Lidia Thompson

Senior Member (Voting Rights)
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Mail Online: Why many of those struck by Long Covid may be suffering from glandular fever: Blood tests on some patients are coming back positive for ‘


Here is a link from ME-pedia on the use use of valaciclovir.

The study that is mentioned on this page showed that, " Improvement occurred over the course of 3-5 months with 85% percent of the patients responding by 3 months, and 92% by 5 months. Symptoms of fatigue, exertion induced malaise, excessive sleep, napping, unrefreshing sleep, headaches, cognitive symptoms, and emotional symptoms all resolved."

Anyone have any thoughts on this?

https://me-pedia.org/wiki/Valaciclovir

And here's a link to an article mentioned on that page:
https://www.psychiatryadvisor.com/h...tiviral-therapy-in-chronic-fatigue-treatment/

As someone who's sickness (probably) started with glandular fever, I would be most interested to know what folk here know about this.
 
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Gosh ... I know I'm treading on thin ice here ... (believe me I know!) ... BUT ... would there be any harm from taking 3 months worth of valaciclovir (which is normally given for genital herpes) and seeing what happens?
What are your thoughts?
 
Gosh ... I know I'm treading on thin ice here ... (believe me I know!) ... BUT ... would there be any harm from taking 3 months worth of valaciclovir (which is normally given for genital herpes) and seeing what happens?
What are your thoughts?

You might get Stevens Johnson syndrome and go blind, or die of agranulocytosis or whatever. Drugs can have nasty effects so are best saved for when they are likely to be helpful.

I suspect that changes in EBV antibody titres after Covid19 are partly just coincidence and partly what is called an anamnestic response - when the immune system is stimulated by a new antigen it often produces a bit more antibody to everything it remembers from before. It looks to me as if Dr Prusty is talking through his hat.
 
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You might get Stevens Johnson syndrome and go blind, or die of agranulocytosis or whatever. Drugs can have nasty effects so are best saved for when they are likely to be helpful.

I suspect that changes in EBV antibody titres after Covid19 are partly just coincidence and partly what is called an anamnestic response - when the immune system is stimulated by a new antigen it often produces a bit more antibody to everything it remembers from before. It looks to me as if Dr Prusty is talking through his hat.

Thanks for this Jonathan.
This is the sort of feedback that I need to hear.

Valaciclovir can be fairly easily bought online (even in the UK).
I therefore assumed it was not particularly dangerous/potent ... not quite at the level of taking paracetamol (at the correct dose) but thereabouts. If this is not the case, I need to stop toying with the idea!

I'm wondering what you think of this article in that case? Could it just be someone trying to make a name for himself by making big claims in the media? (It's not as if we haven't seen this type of behaviour before.)
https://www.psychiatryadvisor.com/h...tiviral-therapy-in-chronic-fatigue-treatment/
 
Personal anecdote about taking valacyclovir, raised in this thread (I have ME/CFS and long covid):

I have been taking valacyclovir for 6 years now. (I had an initial EBV onset when I was a teenager but became much more ill later in my mid 20s, and have been sick for the past 13 years, don't know the subsequent triggering virus. I had shingles as a child.) After a few years an ME/CFS doctor recommended trying the valacyclovir as I still had v high antibody levels to EBV. (This was the rationale, as I recall). (I don't think it was "reactivated"; I am not sure what this means really.)

It appeared to help me re: PEM from physical exercise, so I kept taking it. (It is the second of two medications that really seemed to help me, the other being piracetam for cognitive stuff and PEM after mental tasks, etc) I improved to the point of walking in the park again. I have tried to come off it but I developed hearing loss (I don't know why) which gets worse when I stop taking it. My ENT prescribed courses of acyclovir for this; the first course really cleared up quite a lot of hearing loss - I was very surprised. He said after the event that I'd had a 1 in 5 chance of positive response from antivirals. It was just a week-long course. When it became muffled again months later he suggested more short courses. I now have to continue with a maintenance dose of valacyclovir all the time. My ENT prescribes it now as I don't have a doctor for ME/CFS. (I have been getting my kidney function monitored regularly throughout this time; no change) I hope it's not dangerous but would not want a recurrence of what happened with my hearing when I went off it altogether.

I didn't want to go into a big essay but that is my experience; I am not recommending anything or saying this is a good idea in any way. As it was raised in the thread I thought I'd relate this anecdote.

I had suspected covid last March. I now cannot go out anymore due to PEM. I had a huge deterioration. I doubled the valacyclovir dose to see if it would help me with LC symptoms. I got a bit more energy, but I think that would have happened anyway if I increased my dose. It didn't do anything different.

I have not had any further EBV related antibody tests post long covid. On the one occasion I had repeat testing during the past 6 years, the antibodies still measured above the scale of the test ranges, as they had the first time, so we did not know if there was a change in the level.

I have no idea what it's doing - the medication - and try to take as little as possible. I have wondered whether it may help a subset of patients. I hope it's not too dangerous. :( xx
 
Anecdotally, plenty of people on the longcovid subreddits are reporting reactivated EBV.

Gosh ... I know I'm treading on thin ice here ... (believe me I know!) ... BUT ... would there be any harm from taking 3 months worth of valaciclovir (which is normally given for genital herpes) and seeing what happens?
What are your thoughts?

Thought I'd share: I just saw someone in a long covid group whose doctor prescribed acyclovir for her (after several months of symptoms).
 
I'm wondering what you think of this article in that case? Could it just be someone trying to make a name for himself by making big claims in the media? (It's not as if we haven't seen this type of behaviour before.)
https://www.psychiatryadvisor.com/h...tiviral-therapy-in-chronic-fatigue-treatment/

Didn't see this question, sorry. This is just phoney advertising, not responsible medical care.
I don't know the exact profile of safety with these drugs but in the past things like this have been associated with serious adverse effects. Maybe not often but not rare.
 
I took valtrex (valacyclovir) for 18 months due to recurrent cold sores that started after I got ME/CFS. For most of that 18 months, each time I ran out of valtrex, the cold sores would return. Eventually though, I could stop taking the valtrex and just get an occasional cold sore.

I tracked my ME/CFS symptoms on and off the Valtrex. Disappointingly, the anti-viral made no difference to my ME/CFS.
 
I took valtrex (valacyclovir) for 18 months due to recurrent cold sores that started after I got ME/CFS. For most of that 18 months, each time I ran out of valtrex, the cold sores would return. Eventually though, I could stop taking the valtrex and just get an occasional cold sore.

I tracked my ME/CFS symptoms on and off the Valtrex. Disappointingly, the anti-viral made no difference to my ME/CFS.

Did your ME/CFS involve a viral trigger?
 
I've tried Valtrex a few times, even tiny doses make me feel really unwell. In the end I titrated up to 1/1.5g a day over several weeks, but it just brought on a crash after some mild exertion which lasted about 4-6 weeks. It made my symptoms much worse, severe dizziness on valtrex + depression and joint aches.
 
On the anti-viral Amantadine:

Safety and efficacy of amantadine, modafinil, and methylphenidate for fatigue in multiple sclerosis..., 2020, Nourbakhsh et alThat study found Amantadine didn't help the fatigue of MS. On that thread, two members report trying it and not finding it effective. A study was linked that found that Amantadine did not help fatigue associated with Guillain‐Barré syndrome. A 2025 review confirmed the finding that amantadine is not useful in MS.


Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome, 1997, Plioplys et al
This old paper tested Amantadine in 30 people with CFS; the result was not positive. I don't know what dosage was used (paywall).
Amantadine was poorly tolerated by the CFS patients. Only 15 were able to complete 8 weeks of treatment, the others had to stop taking the medicine due to side effects. In those individuals who completed 8 weeks of treatment, there was no statistically significant difference in any of the clinical parameters that were followed.


Despite the lack of evidence, the Bateman Horne Center has recommended it as reported on this thread:
Cognitive impairment and fatigue medications: Methylphenidate (Ritalin), Modafinil, Armodafinil, amantadine
I recently discovered this resources list in the Bateman Horne Center resources website.
https://batemanhornecenter.org/education/me-cfs/
Have any of you tried any of the following? What was your experience?
Cognitive impairment and fatigue medications:

Methylphenidate (Ritalin)
Modafinil
Armodafinil
amantadine
To date, no member has replied to that thread with their experiences of amantadine. The Bateman Horne Center looks to continue to recommend amantadine, with the website linking this pdf which has a list of recommended medicines (no evidence is cited to support the recommendation):
https://batemanhornecenter.org/wp-c...cs-MECFS-Clinician-Coalition-V1-Feb.-2021.pdf
It notes:
100 mg once or twice daily : May help mild to moderate fatigue. May interact with psychiatric medications.


Amantadine was used to treat PASC fatigue in San Diego, USA, as reported in this paper,
Longitudinal analysis and treatment of neuropsychiatric symptoms in post-acute sequelae of COVID-19, 2023, Liu et al
There's a paywall, but I don't think there was a report of how useful it was.

Unfortunately, what seems to be a fairly passing mention in that paper has been inflated in this Chinese review of treatments for paediatric Long Covid:
Mechanisms and treatment progress of neurological diseases of COVID and L-C19 in children, 2025, Li et al
with the suggestion, poorly substantiated by the Liu et al paper, that it is being widely prescribed. That paper may lead to more use of amantadine.

My conclusion regarding amantadine is that there is no evidence for it being useful for fatigue or other symptoms in ME/CFS. However, ME/CFS clinicians may suggest it. If they do, I think you should ask for their evidence to support its use.
 
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