The Russian word for drugstore is аптека. Interestingly enough, it is related to the English word apothecary. The Ancient Greek prefix απο- meant ‘away’ and the root -θηκ- meant ‘put’, so αποθηκη meant a place you put something away, i.e., a storehouse. From Greek the word went into Latin as apothēca with that same meaning. Eventually the word went into German as Apotheke and into Baltic German as Apteke. Somewhere along the way its meaning specialized into a storehouse for spices (culinary and medicinal) and thence into medicinal spices, whence we get the modern meaning of pharmacy/drugstore. Incidentally, you can see a similar meaning to this day in the Finnish word apteekki and the Swedish and Norwegian word apotek. See how wonderful Russian is? It prepares you to be a tourist in Scandinava as well as Russia! The word declines like this:

Russian drugstores and American drugstores are very different. Russian drugstores primarily sell drugs and perhaps specialized infant formula. And for the most part you don't need a prescription. For instance, this last summer in Russia I came down with giardiasis. A doctor advised metronidazole. I went to the pharmacy, said the name of the drug, and they gave it to me. No prescription necessary. Despite the lack of written prescriptions for most drugs, the word pharmacy behaves pretty much like any other word, without any particular grammatical quirks:

American pharmacies nowadays are more like convenience stores than pharmacies, although of course they still sell medicine. But if I wake up at 2:00 a.m. with a craving for chocolate milk, where do I go? To the 24-hour pharmacy on the corner. When I need to quickly buy a couple batteries, where do I go? The pharmacy on the corner. A cheapo t-shirt? A birthday card? Perfume? A USB flash-drive? Yup, I go to the drugstore. Of course, that's not the cheapest place to go, but when you need a quick and dirty purchase, the pharmacy is even better than 7-11 or Circle K.