Parker was first prescribed zantac at 6 weeks, and I think it was like 0.6ml two times a day?

Zantac is weight sensitive so it won't go on age for the dose, and they have a little book and they will work it out for you, the dose needs to be adjusted with increasing weight.

The daily dose is
mimimum= weight in kg x 5 divide 15
maximum- weight in kg x 10 divide 15

Then you divide that amount by how many times a day you give it.