My experience has been similar to everyone else's. I occasionally get some horrendous allergy outbreaks on the Camino (never at home) and I was once prescribed some pretty strong drugs in a Lisbon hospital, when my condition got really bad and I had no idea what it was. Since then, I have just carried the boxes of those drugs with me whenever I walk. On the several occasions when the symptoms recurred, I just took the boxes to the pharmacist and got more. Pharmacists are likely to exercise a lot more discretion and flexibility than in the US and seem not to be so heavily regulated. In any event, I routinely get prescription drugs there without a prescription.
As Scruffy says, you're likely to find in many small towns that the pharmacists are the only ones with much formal education and are good resources. In my pre-cell phone years, when a family emergency arose at home, I found that pharmacies typically had internet even in little towns with nothing else. When I explained my problem, they always let me use their computers for contacting home.
Pharmacists in Spain are also much more willing to suggest remedies than US pharmacists, in my experience. They seem to serve a more important medical role for the pueblos.