Also a quick Google search will show you that Farmacias del Ahorro (small one in Cihuatlan near the square) also carries it. Not cheap but they can get it.

https://www.fahorro.com/catalog/product/view/id/51099/s/symbicort-160-mcg-4-5-mcg-oral-60-dosis/ahorropagos#:~:text=Farmacias%20del%20Ahorro%20%7C%20Symbicort%20160,en%20l%C3%ADnea%20a%20todo%20M%C3%A9xico