If there is improvement in other areas, then I could see continuing for a few more days. Otherwise, call the psychiatrist today and ask to try ritalin. It is another stimulant, and is also short acting (not all day). Some people do better on one stimulant than another. If ritalin works, there are long acting versions that give coverage all day and don't require the need for a dose during the school day (less hassle for you and difficult child and difficult child can't forget to go take his medications at school). If neither medication works, then you have to look for other solutions. Strattera might help, or it might be the wrong diagnosis or he may just not respond to the medications well.
I did sort of chuckle at the talking nonstop. My difficult child did this, but he started long before we put him on medications. He even talked all night in his sleep. It was constant unless he was reading or playing a video game. By age 4 he had hundreds of books - part because he loved them and part because he would stop talking as he read!
My son has Aspergers, a type of Autism Spectrum Disorders (ASD) and yes, ADHD IS a par of that, but medications were very important and very helpful to him. There is no way he could have gotten through school with ANY type of supports/accommodations with-o medications. It just could not have happened. Not only would he never have listened or done ANYTHING that anyone wanted him to, he was also very aggressive and mean, esp to females. It made the years before he was diagnosis'd a TON of fun - NOT.
With the stims for adhd, Wiz LIKED himself. He could concentrate and complete a train of thought, pay attention on the soccer field and not have to work as hard to do what was expected at school. When we added risperdal, his aggression decreased noticeably. Just because a child has an autistic spectrum disorder and adhd is part of that disorder, does NOT mean that medications are a bad thing. For SOME they are. MWM's son was misdx'd and on a lot of the wrong medications until they just took him off all of them because they did more harm than good. My son got the right diagnosis and medications were a HUGE change for the good. medications are a super personal decision, and it is not easy to find the right medications - it takes a lot of trial and error.
Do you think the diagnosis is right? What was it based on? Are you willing to try another medication? One good thing about trialing stims is that they are fast in, fast out. There is no build up to know if they will work, although sometimes it takes a week or two for the body to fully adjust. They also come out of the body as fast as they go in, so you don't have weeks of tapering the drug to have it leave the body. Esp if you use the hsort acting versions rather than the long acting (same medication, just formulated differently).
Has he gone to school while taking the adderall? What did the teacher say about the talking? If they are seeing the problems, maybe they should also see the solution, at least for one day. It might give another perspective. Also, have you volunteered in the classroom or seen him with his peers? It might be helpful to do this at least 1-2 times (if you can), then you might see what the teachers are talking about when they say he is hyper. Often we are so used to what our kdis do that it seems normal to us. This was quite true wth my difficult child because he was my first child. He was all I knew, and all husband knew. But when we saw him around other kids we saw the differences.
I am not saying your child is or isn't misdiagnosed. What is being done to treat the anxiety? I do know kids who seemed adhd, but when another disorder was treated the adhd sx went away. Anxiety can cause a child to behave in ways that seem like adhd, and I cannot think that stims would help that. If he truly has adhd they should, but they also could add to the anxiety. Are they treating the anxiety at all? With medications or other things? Have you tried meditation, self hypnosis, etc?? Biofeedback is esp helpful - and yes, kids as young as your son CAN learn. You can find things to use at home to teach this. There is a gizmo called a Stress Eraser that you put your index finger in and concentrate on calming yourself and it gives you a display of lights that you try to change as you calm yourself. It is pretty basic biofeedback and can be useful to help anyone. Often kids are able to learn and use biofeedback far easier and more effectively than adults.
Another thing that can look like adhd is food allergies/intolerances. The gluten free/casein free diet is very helpful to some people. Casein is a type of protein in dairy that is often put into other foods, and gluten is a protein in certain grains like wheat. More and more people are finding that anxiety, adhd, aggression and even some symptoms of autism are greatly improved or eliminated when the girlfriend/cf diet is followed rigorously. You do NOT need digestive problems to have problems with gluten and casein. The allergy tests for problems with food are not very reliable and it is entirely possible to have allergy tests show no problem but to show huge improvement on the girlfriend/cf diet anyway. There are a TON of products out that are girlfriend/cf and taste really great now, so it is NOT as hard as it used to be. It might be a way to help with the problems, and can't hurt to look into and to try if it seems promising.
These are just ideas. Sorry if this is too much info.