Biaxin The information I was given didn't list insomnia as a side effect, but I have experienced a terrible case of insomnia only after taking this medicine for 2 days. I wouldn't let the Dr. give me Levaquin for the sinus infection because of the insomnia side effect, but this is just as bad!! I will stop taking it and see if I can get some rest this weekend!!!!! Another on my list of medications to NOT take!!!