Two cents from an Italian: first, do not stop at the first pharmacy. While pharmacists may be wary of selling too powerful drugs to unknown people, they may exercise some discretion; if the first pharmacist does not give you what you need, a second one may. Bring the drug you are taking with you and they may find an equivalent.
Second, if your search for a doctor fails, try an hospital emergency room. If your ailment is not life threatening, be ready to get assigned a low precedence code (for a exemple, a green or white code), wait several hours (five hours is quite standard, they will treat serious cases first), and be ready for a small payment.