I can't tell you about the other med, but I know from personal experiance that Retalin is NOT the drug to be used for autism.
You could try a shot at the thyroid disorder community. They may not be able to give specific info about how the meds work with autism, but they can say whether or not the drug worked for them.
http://www.medhelp.org/forums/show/73
Also keep in mind, there is no drug in the world to treat autism.
Which leads to a personal question but I'll just state bluntly if there was such a drug out and given the choice to take it, I would refuse. I mean why change something that makes me part of who I am? Nothing is perfect. There are drawbacks, but there are strengths too.
Drugs may be able to reduce some of the depression or anxiety, but that's about it.
If there are physical issues needing resolved, you want meds to treat those conditions without affecting anything else. (at least I would believe, that way to avoid unwanted side effects) I think giving that other community a try as well would be a good idea. That way you can get more answers to look at.