For a Br Eng speaker, the answer would be τα ναρκωτικά and τα φάρμακα would be medicines. I say this because a Greek speaker arriving in Britain who tells the customs man that he has "drugs in his suitcase" instead of medicines might spend an uncomfortable hour waiting to be checked out!

I agree. I wrote drugs=ναρκωτικα

ΜΕΤΑΦΡΑΖΕΙ ΤΗΝ ΛΕΞΗ DRUGS=ΦΑΡΜΑΚΑ. ΕΝΩ ΕΙΝΑΙ ΝΑΡΚΩΤΙΚΑ MEDICINE=ΦΑΡΜΑΚΑ!

See here for the definition of "drugs"...

https://en.oxforddictionaries.com/definition/drug

https://dictionary.cambridge.org/dictionary/english/drug?q=drugs

https://www.collinsdictionary.com/dictionary/english/drug

The first definition of "drugs" is "medicine". We call a store that sells medicine a drugstore.