Acyclovir making 2 year old crazy - Help!

[Guest guest]

We are trying Acyclovir (200 mg 1 time) on our 2 year old to treat a

possible virus in the inner ear (not ear infection) and PFAPA

(periodic fever syndrome). He has a sound/voice sensitivity at the 500

+- frequency range. His behavior is extremely erratic (bouncing off

the walls), happy one minute & very upset the next, insomnia, little

appetite and generally very unhappy. I think the loss of sleep is

really effecting him. The hearing sensitiviy is 10 times worse, if

anyone speaks to him he comes unglued. I am not sure if I should

continue or quit, we have been on it for almost 4 weeks. My questions:

1. Has anyone experienced extreme side effects? If so what.

2. Did anyone use this for hearing sensitivities and see results?

3. How long do you try this medication before you see results?

They did say it could get worse before better, but I see no improvements.

Any insight would be greatly appreciated.