Valtrex allergy but can't go without it

[merrick6887]

Hi Doctor,
I am between a rock and a hard place right now. I am a 29M and recently acquired HSV2 a couple of months ago. I've been experiencing a pretty severe systemic symptoms (terrible nausea, headaches, stomach pains, ears ringing loudly, overall just 'sick'). It is a rare reaction, but I spoke to a renowned HSV specialist recently and he said it can happen and can usually take about six months to abate.
If I take 500mg of valacyclovir twice a day, I can get through the workday and feel ok. The problem is, I seem to be allergic to it... if I take it for an extended period, my arms and legs get a bit red and rashy. Might Famvir be any different? Could I take Valtrex paired with an antihistamine like claritin or benadryl to alleviate the allergy symptoms? It appears I can't live without it at this point in time and would gladly take a rash over what I'll experience otherwise.

[Edward W Hook, MD]

I think you're mistaken.  You nee to work through this with someone who is willing to sort this out.  EWH

[merrick6887]

I know, but I've been through the ringer with blood tests and it seems to be the only possibility left (plus, the girl had it, after all). It all began with pretty bad burning in the groin a week after sex. I've read the blood tests are unreliable and can take up to 6+ months to be positive... is there any other way?

[Edward W Hook, MD]

Uh Oh!  In all honesty, the symptoms you report are not at all typical of HSV and when persons are allergic to VCV, the side effects are not dose depenedent.  You do ot know you  have herpes- you need to find out.  I am quite concerned that this is not VCV allergy but something else, perhaps heightened by your clear anxiety over your symptoms and perhaps their relationship to possible HSV.  I urge you to first find out if you do have HSV. In your case I would start with a type specific blood test for herpes.  If positve, then you need to explore the relationship of your symptoms to the drug.  If negative, you need to seek other explanations for your symptoms.  To do otherwise will only furstrate you and your doctors., First things first, find out if you have herpes.  EWH

[merrick6887]

Sorry, I should also mention one more thing: I haven't officially been diagnosed with HSV2. But the evidence is overwhelming... all of this began within a week after unprotected sex with someone who had HSV2. I've had a full STD screen and everything else came up negative (but nothing to swab to test for HSV2).

[merrick6887]

I should mention I've been back on it for about two weeks. About a week ago I tried skipping a day which didn't go well. It was almost two months ago when I contracted it. I've had good days while not on vcv... but not many. At this point the attacks just keep coming every week.

[merrick6887]

Doctor,

Thanks for getting back so quickly. I'm afraid to say it but the rashy skin is clearly linked to the valacyclovir. When I first contracted it, I took large doses daily (2,000-2,500mg), and the rash became very apparent and my doc had me stop taking it immediately. Now out of desperation I've been taking lower doses (500mg twice a day), and so far the rash is very very mild but it's there a bit.

Right now I cannot live without vcv because my symptoms have been pretty much continuous and systemic as I described above. Strangely, I do not have skin symptoms but do have very bad systemic symptoms that seem to almost never stop... I am an unusual case, what can I say. I should mention I am not immunocompromised in any way. Last time I tried skipping a day of vcv, I had severe nausea and pain for days and I can't jeopardize my job by missing more work because of it.

[Edward W Hook, MD]

Welcome to our Forum. Certainly a rash can be a result any drug, including valacyclovir.   It seems to me that you are assuming that this is a valacyclovir rash. Has this been verified by your doctor.  Are you sure that this is the case?   Could anything else be causing this problem?  Does it happen every time you take valacyclovir and stay there.  If the rash is due to VCV, it should not come and go as long as you are taking the drug?

Drug allergies may be either specific to the drug being taken or it may occur within a class of drugs.  Thus, if this is a valacyclovir reaction, you might not react to famciclovir (you would however be likely to react to acyclovir since VCV turns into acyclovir within the body).

Finally, you state you cannot live without VCV.  Why is this?  Was it your first outbreak that was severe (your post is not clear) and if so, I would point out that recurrences typically are far milder than initial outbreaks.  Antihistamines of the sort you describe might reduce symptoms related to valacyclovir but first I would want to be sure that the symptoms you are concerned about would occur and would be due to the VCV.

I've asked you several questions. Perhaps I can add more once you have answered them.  EWH