"my 7.5 year old son has been taking 10mg focalin for nearly a year.  immediately it was a &quot;miracle&quot; for us.  he had good behavior marks in school, could finish his work and we were getting along better at home too.  about a month ago it seemed like maybe he had outgrown his dose, we upped it to 15mg.  immediately again, great results.  but, we spent 4 hours in the er tonight getting 2 ekgs &amp; xrays because of his chest pains and irregular heartbeat.  final diagnosis: stop taking focalin.  as much as i loved the behavior and focus improvements he had from the drug, i love him more and can&#039;t risk damaging his heart."