K.D.
I agree with the person who posted about taking a B complex, that has always helped my son somewhat with focus issues.
The other thing that has helped recently is an Amino Acid supplement (google for Platinum Plus Essential Amino Acids for the one we tried that has helped tremendously) and a zinc supplement (chelated zinc, 15 mg) to help the Amino Acid supplement work. I am amazed at how much these two supplements have helped and I wish I had tried them earlier. He is getting better grades, has a better attitude, remembering his dreams, and having a better memory overall.
Also, we avoid red food coloring as it has made him hyper since he was 2. It is in so many things, but it can be avoided.
For several months now we are trying to avoid high fructose corn syrup, preservatives, additives, etc. as I heard they can cause ADHD symptoms. I do a lot of shopping at Whole Foods and Trader Joes.
Btw, I totally sympathize. We tried a very mild medication once (an antiviral that has a side effect of reducing impulsivity) and he seemed to tolerate it well. But he still wasn't able to focus well, so we were told to increase the dosage. It made me cry to see what it did to him. He held his head and said his brain was racing and it really upset him. We reduced the dosage and it took a week before he felt normal again.
Good luck!