Omega 3 and prescription meds

I posted this also on the alternative board. I'd love any feedback anyone has, as I know VERY little about supplements.

I know basically nothing about the supplement treatments for symptoms so excuse my ignorance. My daughter has not been able to tolerate any stimulant medication for her ADHD symptoms. We currently have her on Desipramine for ADHD and anxiety symptoms. She is also taking Guanfacine to help with impulsiveness and tics. My question is if could/should add Omega 3 to help her with focus, as the Desipramine can help somewhat, but wont do what the stimulants did. I am wondering if we can even combine the two things and if so if it will help. Do people use both prescription meds and natural supplements together and with what kind of success. Also, what about side effects? She suffers greatly from side effects on stimulants (anxiety, tics, loss of appeteite and fatigue from some).

Chase had major acid reflux issues when he took the fish oil and a stimulant...I am not sure if it was the combo, or if he could just not tolerate the fish oil.  I only know that he had a month of almost every night of vomiting at about 2 oclock in the morning.  He would awake, be sick, and then go back to bed, self sufficient little guy that he is.  Sometimes I would hear him up, sometimes not.  By morning, he would usually be fine, inform me that he had been sick, then go off to school.  A few times, he was sick at school, or on the bus and had to come home.  I finally made the connection to the vomiting coinciding with the fish oil supplementation, and once we quit the fish oil, he has had no more trouble.

Apparently, acid reflux sometimes presents as frequent, unexplained vomiting in children....I discovered this in my research.....the fish oil is a fatty acid, the stims can exacerbate acid, and if one is already susceptible, it can be a problem.

That being said, many people have had great success both with fish oil alone and when in combination with the stims.  Chase just physically cannot tolerate the added acid, even though we bought a high grade brand, and gave it to him with food to avoid the usual problems....I am not sure how much help it is with focus, but I think it may help some.