First, Yes, I am familiar with doctors who are arrogant, and really tell you nothing except your "marching orders" such as "Give depakote." After all, we are just stupid little folks with no brain. And they are busy and important and insurance does not pay them to sit around and "chat."
However, there are ways to improve that situation, such as write down questions in advance and be sure to ask them. Take a friend or family member with you to act as an advocate (unfortunately, it may be that a MALE accompanying you can elicit better treatment from some of these arrogant doctors). Another thing we can do is CALL the office with the questions. Then, of course, is the Internet with the medication sites. Many will let you pick "patient" or "physician" and clicking on the "physician" tab can get you the full information about the medication (at least as "full" as the company wishes to reveal. For the real scoop, just do a search on the med and "side-effects" and see what the masses of people taking it are really experiencing. Oh and also be sure to search on the med name and "withdrawal" as well.
Next is what to do about the headaches. Oh, poor baby!!! :(
Some things may help are cold cloths. I don't know if there is CoQ10 for toddlers. Sometimes a dietary change can help such as low carb and/or grain-free (sometimes dairy-free as well). She may want to consult with an Integrative MD who would know about natural tricks of the trade.
For now, she MUST CAL the doctor and make a pest of herself if need be. The boy is in pain. Take him to the ER if necessary!
My younger daughter used to have severe migraines starting from age 2. The pediatrician let her have pediatric liquid Advil (at that time it was prescription).
I really feel for that little boy and his mom.