why is my son taking Divalproex Sodium Delayed-Release ?

His doctor put him on Divalproex Sodium Delayed-Release and I just want to know if there is any danger overdosing on this pill as there is other people in our house who might take his pink medicine by mistake..it has 2702 on the side and also a big V on this oblong pill. but I never knew about such things as I don't even take an aspirin or a vitamin medicine