After penicilin awesome week, help please

[Guest guest]

Hello,

my son had an awesome week after a shot of peniciline. He was more responsive,

more attentive, less anxious and show less stereotypical behaviors.

The second week after the shot he had a regression. His anxiety increased

significantly and he could not achieve the same educational goals he had been

succesful at the week before. He is having serious trouble with attention and

focus.

What shoud I look for?

thanks!