My heart goes out to you. I am sorry I don't know the answer to your question. But if I were you I would call the doctor and speak to him about what other options you have. Tell him the side effects, (which I'm sure he knows already) and let him know that you want to explore other options and you are not comfortable with giving this medication to your child. You can even tell him that you've been holding onto it since you filled the perscription, that might open his eyes to how serious you are about this. It's your child and if you feel that strongly about it then you should let the doctor know. You and your son's doctor should have a good, open relationship because you both have to care for and do what's best for your son.
My daughter is a Type 1 Diabetic, which means she is insulin dependent & has to get insulin shots for every meal she eats. She also has a speech delay and I recently found out she is Dyslexic. She is 6 years old. I was very uncomforatable with the way her school & medical professionals were choosing to deal with her situtation but I called them, went to their offices, asked for scheduled meetings. If something bothered me I let them know.
You said you read reviews that the medication had 10 times more side effects that Ritalin, that is enough to scare any parent away from the drug. Have you tried researching online to see what other options are out there for ADHD? Maybe you can find out what other choices are out there and then you can discuss those specific choices with your son's doctor.
I wish you the best and I hope you and your son will be okay.