There are two types of Intuniv. Long-acting seems to have less fatigue for our child with primary diagnosis of anxiety. Lots of other things on top of that, but anxiety is the main challenge and often presents as ADHD. Intuniv is basically a tiny dose of high blood pressure medication. Be careful using with OTC allergy meds that might intensify fatigue.
DC's psychiatrist is very cautious about meds in pre-teens and communicated a lot with pediatrician and school counselor before prescribing. The Intuniv and CBT over 9 months has helped to take some of the edge off DC's explosiveness at home and impulsiveness at school. We have the same child, and love them deeply, but we've definitely progressed out of crisis mode into manageable, but still challenging stage.
Can't wait for puberty...
good luck OP and others