Chemists.
The tricky thing is that sometimes medicaments with the same active pharmaceutical ingredient have different names around the word.
That is why, it is always a good idea to carry a sufficient supply of medication with you when you first arrive. Once you are about to run out, go to a pharmacist and show them the package and the package insert of your medicine and they will be able to provide you with an equal product.
Lékárna is the Czech word for pharmacy; they are usually recognizable by a green cross near the entrance.
Lekarna
Palackého 5
Prague 5
Phone: 224 946 982
Lekarna
Belgická 37
Prague 2
Phone: 222 519 731
Lekarna
Soukalova 3355
Prague 4
Phone: 244 402 270
Lekarna
Stefanikova 6
Prague 5
Phone: 257 320 918
Lekarna
Heydukova 10
Prague 8
Phone: 266 310 899