Get him on a multiple Vitamin-mineral supplement with antioxidants,Vit C and B Complex,experts say this has the same effiacy as Ritalinalso fish oil has been shown to be helpful, the health food storea carry a Homeopathic treatment called 'Attend" by Vaxa, said to work in 2 weeks ,it works on a sub-molecular level to naturally improve, Focus, concentration and Memory, Attend ballances the left/right brain activity and supports the central nervous system.
You might also want to consider retention before he gets any older. Things will be easier for him if he is not the youngest in his class all his life. He is probably in third grade and it is tough to do now, but it will help. With a short attention span things will only get harder for him in fourth and fifth grade. Good luck with the doctor's appointment, hopefully it is a simple medical problem that can be corrected with diet. If it is ADHD - well that is a medical problem that is correctable too. Good luck.