I'm wondering if there is any chance your son's doctor could switch his medication to one of the ones that many places charge small amounts for; $4 for 30 days, $10 for 90 days worth.

Also, your doctor's office may have samples and would be glad to help you in this situation where you are waiting for insurance approval by giving you samples for now. I am sure the doctor doesn't want your son to go without his medication and some medications cause unpleasant side effects when they are stopped suddenly.

When my insurance changed, I told my doctor that I needed cheaper medications and he was able to switch them. I could not pay several hundred dollars a month for a prescription.