amoxicillin trihydrate as in oral capsules? available in every pharmacy. generic is cheap, farmacias del pueblo sell at 1 pesos, regular pharmacies at 10-20 pesos per pill. goes up from there if you want specific manufacturer.
We have it here in three different colmados, check the ED. The freshest are from calmado RAMON on the main street. That's between GH and RSJ. And... he has icecold Bohemia to take the Amox.