Good morning, I would like to assist you today.
I do understand your concerns for your son. Many children who have been diagnosed with ADHD have the capabilities of learning and doing well in school just like children without the diagnosis. Getting your son to focus and do well in school will take effort and consistency, but it is definitely achievable. I also truly understand your concern about the medication, and how that may have affected your son. I think as a parent, it is never a bad idea to get a second (and sometimes third) opinion of how to best manage your son's ADHD. I think that a good idea would be to take your son to his pediatrician and make him or her aware of your concerns about your son's focus in school. Make him or her aware that medication is not something that you want for your son, and that you are interested in any alternatives that can help your son along the way, including counseling. It might even be a good idea to research and find a pediatrician who specializes in a holistic medicine. Research has shown the holistic (non-drug/natural) approach to ADHD to be effective: http://www.helpguide.org/mental/adhd_add_teaching_strategies.htm
Here is a link to the Holistic Pediatrician Alliance: http://hpakids.org/
You can search in your area for a holistic pediatrician that may suite your family's needs. There are also steps that can be taken with your sons school, at home, and in advance that can help him to achieve at school. This article has a wealth of tips for helping your son in school, including staying in communication with teachers to set up a strategy for your son's learning, learning to manage his ADHD symptoms, as well as methods outside of school that can be used to encourage your son to focus and learn:http://www.helpguide.org/mental/adhd_add_teaching_strategies.htm
If there are any other questions or comments that you have, or if you feel that I have not provided a sufficient answer, please message for "earthsister," and I will do all that I can to assist you.