My 7 Year Old Grandson Accidentally Injested A 0.5 Xanax,

My 7 year old grandson accidentally injested a 0.5 Xanax, 300 mg oxcarbazepine, and a 10mg baclofen. What should I do? I had laid them out on the counter to take at bedtime and ran to the restroom and when I came back they were gone. I asked him if he had taken them and he said yes. He also takes a 5mg Melatonin and 0.01 Clonidine that he had taken before this happened.