I think good ones to start with are mebendazole, quinfamida and decaris. If you are going to Tijuana then I think the very first pharmacy you pass by as you enter the border has decaris there. Right when you walk down the stairs there is a corner store there. Not 40 feet from the circular gate to the u.s. If not then you would need to walk across the walking bridge to Mcdonalds. Millenium pharmacy is on the corner of the same street closest to the u.s. They sell it there for sure. If you have other worms and Daxon is a very good all purpose drug that helps treats a multitude of parasites. You can find albendazole (zentel), praziquantel (cesol) and ivermectin there. Some of the other bendazoles aren't quite as common I think. The pharmacy next to McDonalds is pretty decent. I hope this helps.
David