My son has been taking ADHD medication since seven and now is seventeen. The only one that has worked well and he has taken for six years now is vyvannse. I’d say he had some irritability when he first began the medication, but that leveled out after short while. Honestly, it has been heaven sent. We still have testy days from time to time but overall this medication has been a saving grace. It is quite expensive. It runs 264 for months supply of 50mg, which is overpriced but all medicine is these days. Best of luck on the change and just give it some time because it works really well.