I'm happy that you have asked me to assist you with your child and hope that you can benefit from my many years of helping parents like you.
Can you tell me what the mg dose of the Tylenol tablet is?
they are 500mg each
The toxic dose is greater than 120mg/kg of body weight and at his weight he only took 71mg/kg, thus it is not likely to harm him at all.
His dose is only 100mg every 4-6 hours so while he did take a large dose by the guidelines above he should not suffer at all. If you are in doubt about how many he ate or are still concerned then take him in to an ER where his blood level can be drawn, from which the toxicity potential can be plotted on a graph for this very purpose.