Surtir la receta literally means 'to fill the prescription'. By no means this is related to the over-the-counter purchase in Mexican territory of drugs that require prescription in the U.S. Surtir la receta means to give the physical punishment that is deserved, especially in a violent fashion.
Pancho: Le voy a dar en la madre en cuanto lo vea.
Memo: ¿Vas a surtirle la receta?
Pancho: ¡Con todo! Ya verás que le va a caer la voladora.
Pancho: I am gonna kick his ass as soon as I see him.
Memo: Are you gonna make him pay for what he did?
Pancho: Totally! You'll see, he is so frigging screwed.
Farmacias in Mexico City can be divided into two categories: the ones that sell branded products and the ones that sell generics. Among the latter group, the most ubiquitous chain is "Farmacias Similares", whose mascot (Dr. Simi) is really creepy.