first off let me caution you that I am a clinical psychologist, and as such I do not prescribe medications. While I have knowledge about psychotropic medications and how they are used, I can not offer the same level of expertise as a psychiatrist. That said, I do have extensive experience with making psychiatric diagnoses in children, so I will limit my recommendations to addressing those concerns, and refer you to seek a psychiatrist's guidance to learn more about drug interactions.
The first matter of importance to consider is regarding your son's prescribing physician. If you son's conditions warrant more than one psychotropic drug, I would advise you to seek the care of a pediatric psychiatrist, and not a general practitioner unless that individual has a special training in treating psychiatric disorders. Psychiatrists are specialists, and have experience and deeper knowledge of psychiatric diagnosis, etiology, and treatment than a general practitioner.
Regarding the issue of the danger of these medications, stimulants such as Concerta are widely considered to be among the safest of all psychiatric medications. Cases of sudden death are very rare, and have been linked to undetected heart conditions (the recommendation to physicians is to obtain a thorough clinical history and to conduct examinations with the intent of ruling out contraindications). With regards to the Clonidine (often used to help children increase impulse control and decrease aggressive behaviors) and Zolpidem (brand name Ambien, which I would assume is being given to alleviate the difficulty with sleeping side effect of stimulants) these drugs are often used 'off label' to treat children. This is the case with many psychotropic drugs because of the difficulty of testing their efficacy and safety on child subjects during clinical trials. While Atomoxitine (Strattera) is an alternative to stimulants, it is still a psychotropic drug. As such, it comes with 'side-effects' and an unknown potential impact on the developing brain. It is not clear from my understanding of the literature that it is known to be safer than stimulants, though a psychiatrist will more extensive information on this matter.
Many psychotropics are approved for use to treat pediatric psychiatric disorders if the physician exercises appropriate caution. Use of these drugs in combination would not be an unusual practice if done responsibly. It is not uncommon for children with complex emotional and behavioral issues to receive more than one psychotropic medication. That said, it is always useful to respectfully ask the physician if the patient actually requires multiple drugs, or if therapeutic results could be obtained with fewer medications or lower dosages.
It seems the most pressing issues in your struggle to help your son are: wanting to have some input into his medical care, and questioning the diagnosis. With regards to wanting to be allowed to participate in his medical care, your attorney is the person to consult. Your custody agreement will have information regarding your rights with respect to agreeing to medical treatments and seeking second opinions. I would recommend you contact your attorney or a mediator to learn more about how to resolve this issue with as little conflict as possible.
With respect to the diagnosis, it is unclear from your post how your son was determined to have ADHD. While some physicians diagnosis on the basis of a quick interview, and some use symptom checklists, the most responsible way to determine if a child has ADHD is to refer him for psychological or neuropsychological assessment. ADHD is frequently diagnosed by the presence of symptoms, yet it is important to note that symptoms such as impulsivity or forgetfulness can also be caused by anxiety, depression, or other factors. It is necessary to rule-out other factors prior to jumping to the conclusion that ADHD is the best explanation for the child's presenting problem. I would encourage you to sit down with your son's mother and discuss having your son assessed by a licensed clinical psychologist (not a school psychologist in this case) or neuropsychologist. Once you have the data from the testing, you will be in an excellent position to advocate for your son.
Disclaimer: This post was written for informational purposes only. It is never intended to replace face-to-face psychological or psychiatric treatment. This post is not intended to create a clinician-patient relationship, nor to give or rule-out a diagnosis.
My mum put me on a holistic version of Ritalin called pycnogenol which dd not have any side effects, inf act on top of helping me with consontration it prevented me from getting sick as well. Because of it I did not have growth issues and now stand at an overly natural height of 5"10 (which is annoying for a girl) Also keep away from red dyes in food, it makes ADD/ADHD positive kids twice as hyperactive. Also the best thing for me was patience when people got fustrated at me, I got fustrated at myself (which results in screaming and crying). Break down study and homework sessions with snack breaks but keep him at the table other wise you'll loose him, forcing ADD Postivie Children to sit threw a 2 - 3 hour homework workload just won't work.
Good Luck xox